diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures.spec.ts b/packages/@lwc/engine-server/src/__tests__/fixtures.spec.ts
index b9a54d4eb8..2f63877a16 100755
--- a/packages/@lwc/engine-server/src/__tests__/fixtures.spec.ts
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures.spec.ts
@@ -11,15 +11,12 @@ import { rollup } from 'rollup';
 import lwcRollupPlugin from '@lwc/rollup-plugin';
 import { testFixtureDir, formatHTML } from '@lwc/test-utils-lwc-internals';
 import { setFeatureFlagForTest } from '../index';
-import type { FeatureFlagName } from '@lwc/features/dist/types';
 import type { RollupLwcOptions } from '@lwc/rollup-plugin';
 import type * as lwc from '../index';
 
 interface FixtureModule {
-    tagName: string;
     default: typeof lwc.LightningElement;
-    props?: { [key: string]: any };
-    features?: any[];
+    props?: { [key: string]: unknown };
 }
 
 vi.setConfig({ testTimeout: 10_000 /* 10 seconds */ });
@@ -132,20 +129,10 @@ function testFixtures(options?: RollupLwcOptions) {
 
             let result;
             let err;
-            let features: FeatureFlagName[] = [];
             try {
-                const module = (await import(compiledFixturePath)) as FixtureModule;
-
-                features = module!.features ?? [];
-                features.forEach((flag) => {
-                    lwcEngineServer!.setFeatureFlagForTest(flag, true);
-                });
+                const { default: module } = (await import(compiledFixturePath)) as FixtureModule;
                 result = formatHTML(
-                    lwcEngineServer!.renderComponent(
-                        module!.tagName,
-                        module!.default,
-                        config?.props ?? {}
-                    )
+                    lwcEngineServer!.renderComponent('fixture-test', module, config?.props ?? {})
                 );
             } catch (_err: any) {
                 if (_err?.name === 'AssertionError') {
@@ -154,10 +141,6 @@ function testFixtures(options?: RollupLwcOptions) {
                 err = _err?.message || 'An empty error occurred?!';
             }
 
-            features.forEach((flag) => {
-                lwcEngineServer!.setFeatureFlagForTest(flag, false);
-            });
-
             return {
                 'expected.html': result,
                 'error.txt': err,
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/expected.html
index 0e6e634163..3ee5777c96 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/expected.html
index f821309f78..b9049e0df6 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
@@ -6,4 +6,4 @@
       </div>
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each-with-rendered-item/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each-with-rendered-item/expected.html
index e512105443..8320a94d31 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each-with-rendered-item/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each-with-rendered-item/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     ab
     <div data-foo="1">
@@ -6,4 +6,4 @@
     </div>
     de
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each-with-rendered-item/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each-with-rendered-item/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each-with-rendered-item/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each-with-rendered-item/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each/expected.html
index 841e1096c3..00d1c4a05f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     ab
     <div>
@@ -6,4 +6,4 @@
     </div>
     de
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-for-each/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-iterator/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-iterator/expected.html
index 841e1096c3..00d1c4a05f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-iterator/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-iterator/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     ab
     <div>
@@ -6,4 +6,4 @@
     </div>
     de
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-iterator/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-iterator/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-iterator/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep-iterator/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep/expected.html
index dcc1ec185d..313e776d4c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       abc
     </div>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep2/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep2/expected.html
index 841e1096c3..00d1c4a05f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep2/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep2/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     ab
     <div>
@@ -6,4 +6,4 @@
     </div>
     de
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep2/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep2/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep2/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/deep2/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/emptier/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/emptier/expected.html
index 0e6e634163..3ee5777c96 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/emptier/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/emptier/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/emptier/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/emptier/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/emptier/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/emptier/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty/expected.html
index 0e6e634163..3ee5777c96 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty1/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty1/expected.html
index 0e6e634163..3ee5777c96 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty1/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty1/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty1/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty1/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty1/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty1/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty2/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty2/expected.html
index 0e6e634163..3ee5777c96 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty2/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty2/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty2/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty2/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty2/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty2/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty3/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty3/expected.html
index 0e6e634163..3ee5777c96 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty3/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty3/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty3/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty3/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty3/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/empty3/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping-single/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping-single/expected.html
index 84f3b7dd97..240b27bf86 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping-single/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping-single/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       &amp;minus;
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping-single/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping-single/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping-single/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping-single/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping/expected.html
index 84f3b7dd97..240b27bf86 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       &amp;minus;
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/html-escaping/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/if-as-sibling/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/if-as-sibling/expected.html
index 6dde279973..7a556b9f26 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/if-as-sibling/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/if-as-sibling/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       ‍‍‍
@@ -7,4 +7,4 @@
       ‍‍
     </div>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/if-as-sibling/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/if-as-sibling/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/if-as-sibling/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/if-as-sibling/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/just-comments/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/just-comments/expected.html
index 9b9b476fdb..b174a7c0ab 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/just-comments/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/just-comments/expected.html
@@ -1,6 +1,6 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/just-comments/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/just-comments/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/just-comments/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/just-comments/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/lwcIf-as-sibling/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/lwcIf-as-sibling/expected.html
index d3872f658a..5efee2b7b7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/lwcIf-as-sibling/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/lwcIf-as-sibling/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       ‍
@@ -11,4 +11,4 @@
       ‍‍
     </div>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/lwcIf-as-sibling/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/lwcIf-as-sibling/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/lwcIf-as-sibling/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/lwcIf-as-sibling/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-dynamic/expected.html
index 0b6046e94e..1166f16679 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-dynamic/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       haha0true
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-dynamic/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-literals-outside/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-literals-outside/expected.html
index 2996fd08ab..37fa2b7b7c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-literals-outside/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-literals-outside/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       totoyolototoyolo
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-literals-outside/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-literals-outside/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-literals-outside/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty-literals-outside/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty/expected.html
index 9bf7cdc895..9eb6955362 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       yolototo
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty1/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty1/expected.html
index 16b1733ab0..158d94f5ac 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty1/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty1/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       bar
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty1/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty1/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty1/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty1/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty2/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty2/expected.html
index 16b1733ab0..158d94f5ac 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty2/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty2/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       bar
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty2/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty2/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty2/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty2/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty3/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty3/expected.html
index f289dd5b7c..f2988475a0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty3/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty3/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       barbaz
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty3/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty3/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty3/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/nonempty3/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/text-comment-text-comment/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/text-comment-text-comment/expected.html
index 0e6e634163..3ee5777c96 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/text-comment-text-comment/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/text-comment-text-comment/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/text-comment-text-comment/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/text-comment-text-comment/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/text-comment-text-comment/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/text-comment-text-comment/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/comments-then-element/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/comments-then-element/expected.html
index f3d70401af..ed7f1134d1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/comments-then-element/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/comments-then-element/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
@@ -9,4 +9,4 @@
       </div>
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/comments-then-element/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/comments-then-element/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/comments-then-element/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/comments-then-element/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier-with-text-comment-text/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier-with-text-comment-text/expected.html
index 0b67b66ca9..ec91d3249e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier-with-text-comment-text/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier-with-text-comment-text/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       <!--a-->
@@ -12,4 +12,4 @@
       <!--e-->
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier-with-text-comment-text/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier-with-text-comment-text/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier-with-text-comment-text/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier-with-text-comment-text/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier/expected.html
index b4d5bbd885..2d54c69e90 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
@@ -7,4 +7,4 @@
       <!--yolo-->
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/emptier/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/empty copy/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/empty copy/expected.html
index 79ceaa13f4..585a9edc16 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/empty copy/expected.html	
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/empty copy/expected.html	
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <!---->
     ‍
@@ -6,4 +6,4 @@
     <!-- preserved comment after true -->
     <!-- preserved comment after false -->
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/empty copy/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/empty copy/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/empty copy/index.js	
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/empty copy/index.js	
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/just-comments/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/just-comments/expected.html
index 8958106119..836ac4b050 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/just-comments/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/just-comments/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       <!--a-->
@@ -6,4 +6,4 @@
       <!--c-->
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/just-comments/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/just-comments/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/just-comments/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/just-comments/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments/expected.html
index 810e2325ee..736449cccb 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       <!-- yolo -->
@@ -8,4 +8,4 @@
       <!-- yolo -->
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments2/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments2/expected.html
index 810e2325ee..736449cccb 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments2/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments2/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       <!-- yolo -->
@@ -8,4 +8,4 @@
       <!-- yolo -->
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments2/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments2/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments2/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments2/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments3/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments3/expected.html
index 4c4b5d65a2..9e5cdefaf7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments3/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments3/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       <!-- yolo -->
@@ -8,4 +8,4 @@
       <!-- yolo -->
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments3/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments3/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments3/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-on/preserve-comments3/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-getter/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-getter/expected.html
index 4b6d956f1a..723d0693a7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-getter/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-getter/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -11,4 +11,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-getter/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-getter/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-getter/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-getter/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter-getter/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter-getter/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter-getter/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter-getter/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter/expected.html
index 4b6d956f1a..723d0693a7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -11,4 +11,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/decorated-setter/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/inherited/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/api/inherited/expected.html
index cc6553bd1b..3fbda59116 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/inherited/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/inherited/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -21,4 +21,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/inherited/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/api/inherited/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/inherited/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/inherited/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/property/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/api/property/expected.html
index 73ad529907..4cadf4dec3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/property/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/property/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -11,4 +11,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/api/property/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/api/property/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/api/property/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/api/property/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-and-class-modify/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-and-class-modify/expected.html
index 7424950db4..ec440f2215 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-and-class-modify/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-and-class-modify/expected.html
@@ -1,4 +1,4 @@
-<x-cmp aria-label="haha" class="woot yolo" data-foo="bar" data-lwc-host-mutated="aria-label bar class data-foo foo">
+<fixture-test aria-label="haha" class="woot yolo" data-foo="bar" data-lwc-host-mutated="aria-label bar class data-foo foo">
   <template shadowrootmode="open">
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-and-class-modify/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-and-class-modify/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-and-class-modify/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-and-class-modify/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria-modify/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria-modify/expected.html
index 4e3c99df65..7568bc97c6 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria-modify/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria-modify/expected.html
@@ -1,4 +1,4 @@
-<x-cmp aria-activedescendant="foo" aria-busy="true" data-lwc-host-mutated="aria-activedescendant aria-busy">
+<fixture-test aria-activedescendant="foo" aria-busy="true" data-lwc-host-mutated="aria-activedescendant aria-busy">
   <template shadowrootmode="open">
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria-modify/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria-modify/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria-modify/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria-modify/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/dynamic/expected.html
index 6baed8c3be..9ab86867a0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -121,4 +121,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/dynamic/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/static/expected.html
index cd33fb0ad4..04d41af511 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/static/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child aria-activedescendant="foo" aria-atomic="foo" aria-autocomplete="foo" aria-braillelabel="foo" aria-brailleroledescription="foo" aria-busy="foo" aria-checked="foo" aria-colcount="foo" aria-colindex="foo" aria-colindextext="foo" aria-colspan="foo" aria-controls="foo" aria-current="foo" aria-describedby="foo" aria-description="foo" aria-details="foo" aria-disabled="foo" aria-errormessage="foo" aria-expanded="foo" aria-flowto="foo" aria-haspopup="foo" aria-hidden="foo" aria-invalid="foo" aria-keyshortcuts="foo" aria-label="foo" aria-labelledby="foo" aria-level="foo" aria-live="foo" aria-modal="foo" aria-multiline="foo" aria-multiselectable="foo" aria-orientation="foo" aria-owns="foo" aria-placeholder="foo" aria-posinset="foo" aria-pressed="foo" aria-readonly="foo" aria-relevant="foo" aria-required="foo" aria-roledescription="foo" aria-rowcount="foo" aria-rowindex="foo" aria-rowindextext="foo" aria-rowspan="foo" aria-selected="foo" aria-setsize="foo" aria-sort="foo" aria-valuemax="foo" aria-valuemin="foo" aria-valuenow="foo" aria-valuetext="foo" role="foo">
       <template shadowrootmode="open">
@@ -7,4 +7,4 @@
     <div aria-activedescendant="foo" aria-atomic="foo" aria-autocomplete="foo" aria-braillelabel="foo" aria-brailleroledescription="foo" aria-busy="foo" aria-checked="foo" aria-colcount="foo" aria-colindex="foo" aria-colindextext="foo" aria-colspan="foo" aria-controls="foo" aria-current="foo" aria-describedby="foo" aria-description="foo" aria-details="foo" aria-disabled="foo" aria-errormessage="foo" aria-expanded="foo" aria-flowto="foo" aria-haspopup="foo" aria-hidden="foo" aria-invalid="foo" aria-keyshortcuts="foo" aria-label="foo" aria-labelledby="foo" aria-level="foo" aria-live="foo" aria-modal="foo" aria-multiline="foo" aria-multiselectable="foo" aria-orientation="foo" aria-owns="foo" aria-placeholder="foo" aria-posinset="foo" aria-pressed="foo" aria-readonly="foo" aria-relevant="foo" aria-required="foo" aria-roledescription="foo" aria-rowcount="foo" aria-rowindex="foo" aria-rowindextext="foo" aria-rowspan="foo" aria-selected="foo" aria-setsize="foo" aria-sort="foo" aria-valuemax="foo" aria-valuemin="foo" aria-valuenow="foo" aria-valuetext="foo" role="foo">
     </div>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/static/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-aria/static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean-expr/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean-expr/expected.html
index 17eea8b190..861dae4541 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean-expr/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean-expr/expected.html
@@ -1,5 +1,5 @@
-<x-attribute-boolean-expr>
+<fixture-test>
   <template shadowrootmode="open">
     <input disabled readonly title="foo">
   </template>
-</x-attribute-boolean-expr>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean-expr/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean-expr/index.js
index a8ff7a3d90..0a386e61f0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean-expr/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean-expr/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-boolean-expr';
 export { default } from 'x/attribute-boolean-expr';
-export * from 'x/attribute-boolean-expr';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean/expected.html
index 08f1b8de93..34615d0cd7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean/expected.html
@@ -1,5 +1,5 @@
-<x-attribute-boolean>
+<fixture-test>
   <template shadowrootmode="open">
     <input readonly required type="checkbox">
   </template>
-</x-attribute-boolean>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean/index.js
index b932b80e30..90d609e41f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-boolean/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-boolean';
 export { default } from 'x/attribute-boolean';
-export * from 'x/attribute-boolean';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/array/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/array/expected.html
index c351b15558..a8081a7ac0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/array/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/array/expected.html
@@ -1,6 +1,6 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <button class="button__icon">
     </button>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/array/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/array/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/array/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/array/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/child/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/child/expected.html
index 7ff2494fe4..6b4fc2ad78 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/child/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/child/expected.html
@@ -1,8 +1,8 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child class="button__icon">
       <template shadowrootmode="open">
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/child/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/child/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/child/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/child/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/component/expected.html
index 7ff2494fe4..6b4fc2ad78 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/component/expected.html
@@ -1,8 +1,8 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child class="button__icon">
       <template shadowrootmode="open">
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/component/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/dynamic/expected.html
index a014566e41..13d808f985 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -171,4 +171,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/dynamic/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/object/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/object/expected.html
index c351b15558..a8081a7ac0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/object/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/object/expected.html
@@ -1,6 +1,6 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <button class="button__icon">
     </button>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/object/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/object/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/object/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/object/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/static/expected.html
index ab0806af6b..9fc0128bfe 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/static/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -61,4 +61,4 @@
     <div class="newlines">
     </div>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/static/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/unstyled/static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/dynamic/expected.html
index 981f56e801..bdd02d6c92 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child class="lwc-5h3d35cke7v-host" data-lwc-host-scope-token="lwc-5h3d35cke7v-host">
       <template shadowrootmode="open">
@@ -235,4 +235,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/dynamic/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/static/expected.html
index 5323facc7e..3a4bcc4564 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/static/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child class="lwc-5h3d35cke7v-host" data-lwc-host-scope-token="lwc-5h3d35cke7v-host">
       <template shadowrootmode="open">
@@ -111,4 +111,4 @@
     <div class="newlines">
     </div>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/static/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-child/static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/dynamic/expected.html
index afc418d9b7..50e0996efc 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-parent class="lwc-ts1rr7v761-host" data-lwc-host-scope-token="lwc-ts1rr7v761-host">
+<fixture-test class="lwc-ts1rr7v761-host" data-lwc-host-scope-token="lwc-ts1rr7v761-host">
   <template shadowrootmode="open">
     <style class="lwc-ts1rr7v761" type="text/css">
       :host {background: green;}
@@ -174,4 +174,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/dynamic/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/static/expected.html
index 1f66349137..e33e9e1d91 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/static/expected.html
@@ -1,4 +1,4 @@
-<x-parent class="lwc-ts1rr7v761-host" data-lwc-host-scope-token="lwc-ts1rr7v761-host">
+<fixture-test class="lwc-ts1rr7v761-host" data-lwc-host-scope-token="lwc-ts1rr7v761-host">
   <template shadowrootmode="open">
     <style class="lwc-ts1rr7v761" type="text/css">
       :host {background: green;}
@@ -84,4 +84,4 @@
     <div class="lwc-ts1rr7v761 newlines">
     </div>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/static/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles-only-in-parent/static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/dynamic/expected.html
index bd44bdcea4..a9d9464c89 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-parent class="lwc-ts1rr7v761-host" data-lwc-host-scope-token="lwc-ts1rr7v761-host">
+<fixture-test class="lwc-ts1rr7v761-host" data-lwc-host-scope-token="lwc-ts1rr7v761-host">
   <template shadowrootmode="open">
     <style class="lwc-ts1rr7v761" type="text/css">
       :host {background: green;}
@@ -276,4 +276,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/dynamic/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/static/expected.html
index 0c6290949a..bf0afd6296 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/static/expected.html
@@ -1,4 +1,4 @@
-<x-parent class="lwc-ts1rr7v761-host" data-lwc-host-scope-token="lwc-ts1rr7v761-host">
+<fixture-test class="lwc-ts1rr7v761-host" data-lwc-host-scope-token="lwc-ts1rr7v761-host">
   <template shadowrootmode="open">
     <style class="lwc-ts1rr7v761" type="text/css">
       :host {background: green;}
@@ -94,4 +94,4 @@
     <div class="lwc-ts1rr7v761 newlines">
     </div>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/static/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-class/with-scoped-styles/static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-aria/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-aria/expected.html
index 1dbbfe8046..45abd01dec 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-aria/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-aria/expected.html
@@ -1,8 +1,8 @@
-<x-attribute-component-aria>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child aria-valuemax="100" aria-valuemin="0" aria-valuenow="20" role="progressbar">
       <template shadowrootmode="open">
       </template>
     </x-child>
   </template>
-</x-attribute-component-aria>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-aria/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-aria/index.js
index 4e20b5a665..602a92ebaf 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-aria/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-aria/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-component-aria';
 export { default } from 'x/attribute-component-aria';
-export * from 'x/attribute-component-aria';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-global-html/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-global-html/expected.html
index c4a1b8b6e4..77a082d866 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-global-html/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-global-html/expected.html
@@ -1,4 +1,4 @@
-<x-attribute-component-global-html>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child accesskey="A" class="bar foo" data-test="test" draggable="true" hidden id="foo" spellcheck="true" style="color: red; background: blue;" tabindex="-1">
       <template shadowrootmode="open">
@@ -14,4 +14,4 @@
       </template>
     </x-child>
   </template>
-</x-attribute-component-global-html>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-global-html/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-global-html/index.js
index 8f6d4757bd..f00f43861a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-global-html/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-component-global-html/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-component-global-html';
 export { default } from 'x/attribute-component-global-html';
-export * from 'x/attribute-component-global-html';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-escape/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-escape/expected.html
index ec74613e35..6f9dffee09 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-escape/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-escape/expected.html
@@ -1,4 +1,4 @@
-<x-attribute-dynamic-escape>
+<fixture-test>
   <template shadowrootmode="open">
     <div data-attr="&quot;>
     </div>
@@ -6,4 +6,4 @@
     <div attr=&quot;">
     </div>
   </template>
-</x-attribute-dynamic-escape>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-escape/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-escape/index.js
index 437903400a..dedcd82a6c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-escape/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-escape/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-dynamic-escape';
 export { default } from 'x/attribute-dynamic-escape';
-export * from 'x/attribute-dynamic-escape';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-with-scoped-css/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-with-scoped-css/expected.html
index 1c8dcb098b..cd3f3781c1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-with-scoped-css/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-with-scoped-css/expected.html
@@ -1,4 +1,4 @@
-<x-attribute-dynamic-with-scoped-css class="lwc-47oqt8q93b2-host" data-lwc-host-scope-token="lwc-47oqt8q93b2-host">
+<fixture-test class="lwc-47oqt8q93b2-host" data-lwc-host-scope-token="lwc-47oqt8q93b2-host">
   <template shadowrootmode="open">
     <style class="lwc-47oqt8q93b2" type="text/css">
       div.lwc-47oqt8q93b2 {color: black;}div.kree.lwc-47oqt8q93b2 {color: blue;}
@@ -7,4 +7,4 @@
       In the middle of my backswing?!
     </div>
   </template>
-</x-attribute-dynamic-with-scoped-css>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-with-scoped-css/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-with-scoped-css/index.js
index 1b0cb998bd..922e829cec 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-with-scoped-css/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic-with-scoped-css/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-dynamic-with-scoped-css';
 export { default } from 'x/attribute-dynamic-with-scoped-css';
-export * from 'x/attribute-dynamic-with-scoped-css';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic/expected.html
index 9a57cdb0b1..c28fc3c866 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-attribute-dynamic>
+<fixture-test>
   <template shadowrootmode="open">
     <div data-foo="foo">
     </div>
@@ -9,4 +9,4 @@
     <div class="foo" data-foo="foo" style="color: red;">
     </div>
   </template>
-</x-attribute-dynamic>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic/index.js
index c52dab3616..64945ded7a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-dynamic';
 export { default } from 'x/attribute-dynamic';
-export * from 'x/attribute-dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-empty-string/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-empty-string/expected.html
index f68f72b596..fb47ce298d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-empty-string/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-empty-string/expected.html
@@ -1,4 +1,4 @@
-<x-test>
+<fixture-test>
   <template shadowrootmode="open">
     <div data-foo>
     </div>
@@ -7,4 +7,4 @@
     <div data-foo>
     </div>
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-empty-string/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-empty-string/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-empty-string/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-empty-string/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/undeclared/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/undeclared/expected.html
index 2d3393114f..99021d1133 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/undeclared/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/undeclared/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child accesskey="foo" aria-activedescendant="foo" aria-atomic="foo" aria-autocomplete="foo" aria-busy="foo" aria-checked="foo" aria-colcount="foo" aria-colindex="foo" aria-colspan="foo" aria-controls="foo" aria-current="foo" aria-describedby="foo" aria-details="foo" aria-disabled="foo" aria-errormessage="foo" aria-expanded="foo" aria-flowto="foo" aria-haspopup="foo" aria-hidden="foo" aria-invalid="foo" aria-keyshortcuts="foo" aria-label="foo" aria-labelledby="foo" aria-level="foo" aria-live="foo" aria-modal="foo" aria-multiline="foo" aria-multiselectable="foo" aria-orientation="foo" aria-owns="foo" aria-placeholder="foo" aria-posinset="foo" aria-pressed="foo" aria-readonly="foo" aria-relevant="foo" aria-required="foo" aria-roledescription="foo" aria-rowcount="foo" aria-rowindex="foo" aria-rowspan="foo" aria-selected="foo" aria-setsize="foo" aria-sort="foo" aria-valuemax="foo" aria-valuemin="foo" aria-valuenow="foo" aria-valuetext="foo" dir="foo" draggable="foo" exportparts="foo" id="foo" lang="foo" role="foo" spellcheck="foo" tabindex="foo" title="foo">
       <template shadowrootmode="open">
@@ -329,4 +329,4 @@
       </template>
     </x-child>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/undeclared/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/undeclared/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/undeclared/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/undeclared/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/with-@api/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/with-@api/expected.html
index 9a61b50795..eae746749d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/with-@api/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/with-@api/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child exportparts="foo">
       <template shadowrootmode="open">
@@ -329,4 +329,4 @@
       </template>
     </x-child>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/with-@api/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/with-@api/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/with-@api/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/with-@api/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/without-@api/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/without-@api/expected.html
index 72e5459916..03c3222a10 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/without-@api/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/without-@api/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child accesskey="foo" aria-activedescendant="foo" aria-atomic="foo" aria-autocomplete="foo" aria-busy="foo" aria-checked="foo" aria-colcount="foo" aria-colindex="foo" aria-colspan="foo" aria-controls="foo" aria-current="foo" aria-describedby="foo" aria-details="foo" aria-disabled="foo" aria-errormessage="foo" aria-expanded="foo" aria-flowto="foo" aria-haspopup="foo" aria-hidden="foo" aria-invalid="foo" aria-keyshortcuts="foo" aria-label="foo" aria-labelledby="foo" aria-level="foo" aria-live="foo" aria-modal="foo" aria-multiline="foo" aria-multiselectable="foo" aria-orientation="foo" aria-owns="foo" aria-placeholder="foo" aria-posinset="foo" aria-pressed="foo" aria-readonly="foo" aria-relevant="foo" aria-required="foo" aria-roledescription="foo" aria-rowcount="foo" aria-rowindex="foo" aria-rowspan="foo" aria-selected="foo" aria-setsize="foo" aria-sort="foo" aria-valuemax="foo" aria-valuemin="foo" aria-valuenow="foo" aria-valuetext="foo" dir="foo" draggable="foo" exportparts="foo" id="foo" lang="foo" role="foo" spellcheck="foo" tabindex="foo" title="foo">
       <template shadowrootmode="open">
@@ -329,4 +329,4 @@
       </template>
     </x-child>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/without-@api/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/without-@api/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/without-@api/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/as-component-prop/without-@api/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/basic/expected.html
index c749602bab..78a0783f8d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/basic/expected.html
@@ -1,6 +1,6 @@
-<x-attribute-global-html>
+<fixture-test>
   <template shadowrootmode="open">
     <div accesskey="A" class="bar foo" contenteditable="true" data-test="test" draggable="true" hidden id="foo" itemprop="foo" lang="fr" spellcheck="true" style="color: red; background: blue;" tabindex="-1" title="foo">
     </div>
   </template>
-</x-attribute-global-html>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/basic/index.js
index 87e7aa8eca..a53e256853 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-global-html/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-global-html';
 export { default } from 'x/attribute-global-html';
-export * from 'x/attribute-global-html';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-live-bindings/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-live-bindings/expected.html
index a4703c9711..4c20e55d85 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-live-bindings/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-live-bindings/expected.html
@@ -1,4 +1,4 @@
-<x-attribute-live-bindings>
+<fixture-test>
   <template shadowrootmode="open">
     <p>
       Checked: 
@@ -21,4 +21,4 @@
       <input type="text">
     </p>
   </template>
-</x-attribute-live-bindings>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-live-bindings/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-live-bindings/index.js
index c9d40f7cd8..b3ce3cba87 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-live-bindings/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-live-bindings/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-live-bindings';
 export { default } from 'x/attribute-live-bindings';
-export * from 'x/attribute-live-bindings';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-modify-uppercase/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-modify-uppercase/expected.html
index eb4f3a5f72..582b52f0b1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-modify-uppercase/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-modify-uppercase/expected.html
@@ -1,4 +1,4 @@
-<x-cmp aria-label="haha" data-foo="bar" data-lwc-host-mutated="aria-label data-bar data-foo">
+<fixture-test aria-label="haha" data-foo="bar" data-lwc-host-mutated="aria-label data-bar data-foo">
   <template shadowrootmode="open">
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-modify-uppercase/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-modify-uppercase/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-modify-uppercase/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-modify-uppercase/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-namespace/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-namespace/expected.html
index ea4609bec8..7098ad9956 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-namespace/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-namespace/expected.html
@@ -1,4 +1,4 @@
-<x-attribute-namespace>
+<fixture-test>
   <template shadowrootmode="open">
     <a xml:lang="french">
     </a>
@@ -6,4 +6,4 @@
       <image xlink:title="bonjour"/>
     </svg>
   </template>
-</x-attribute-namespace>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-namespace/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-namespace/index.js
index 1e912da3a9..10987fa422 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-namespace/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-namespace/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-namespace';
 export { default } from 'x/attribute-namespace';
-export * from 'x/attribute-namespace';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-null/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-null/expected.html
index 938c885cc2..c4c824186e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-null/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-null/expected.html
@@ -1,4 +1,4 @@
-<x-test aria-describedby="undefined" aria-label="null" aria-labelledby="undefined" data-bar-set-attribute="null" data-foo-set-attribute="null" data-lwc-host-mutated="aria-describedby aria-description aria-label aria-labelledby data-bar-set-attribute data-foo-set-attribute">
+<fixture-test aria-describedby="undefined" aria-label="null" aria-labelledby="undefined" data-bar-set-attribute="null" data-foo-set-attribute="null" data-lwc-host-mutated="aria-describedby aria-description aria-label aria-labelledby data-bar-set-attribute data-foo-set-attribute">
   <template shadowrootmode="open">
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-null/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-null/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-null/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-null/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-scoped-id/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-scoped-id/expected.html
index ee3e782b27..24c659cc29 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-scoped-id/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-scoped-id/expected.html
@@ -1,4 +1,4 @@
-<x-attribute-scoped-id>
+<fixture-test>
   <template shadowrootmode="open">
     <div class="sanjo" id="sanjo">
     </div>
@@ -21,4 +21,4 @@
       </map>
     </div>
   </template>
-</x-attribute-scoped-id>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-scoped-id/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-scoped-id/index.js
index ca6d309e25..4640fa7d4d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-scoped-id/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-scoped-id/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-scoped-id';
 export { default } from 'x/scoped-id';
-export * from 'x/scoped-id';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-static/expected.html
index e514649378..ba7d782cee 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-static/expected.html
@@ -1,6 +1,6 @@
-<x-attribute-static>
+<fixture-test>
   <template shadowrootmode="open">
     <div class="bar foo foo-bar" data-foo="foo" style="color: red; background-color: blue;">
     </div>
   </template>
-</x-attribute-static>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-static/index.js
index 2d9bfb318f..02425a4dde 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-static';
 export { default } from 'x/attribute-static';
-export * from 'x/attribute-static';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/basic/expected.html
index 46af873ead..adf63541ad 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/basic/expected.html
@@ -1,4 +1,4 @@
-<x-attribute-style>
+<fixture-test>
   <template shadowrootmode="open">
     <div style="color: red;">
     </div>
@@ -33,4 +33,4 @@
       </template>
     </x-child>
   </template>
-</x-attribute-style>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/basic/index.js
index f9705aa749..0ee6ccf569 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attribute-style';
 export { default } from 'x/attribute-style';
-export * from 'x/attribute-style';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/dynamic/expected.html
index 6f64793a8a..748a42ab5d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -271,4 +271,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/dynamic/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attribute-style/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attributes-aria/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/attributes-aria/expected.html
index 511c7650b9..de032b3b15 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attributes-aria/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attributes-aria/expected.html
@@ -1,4 +1,4 @@
-<x-attributes-aria>
+<fixture-test>
   <template shadowrootmode="open">
     <span id="label-id">
       This is a section
@@ -10,4 +10,4 @@
       I am a progress bar
     </div>
   </template>
-</x-attributes-aria>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/attributes-aria/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/attributes-aria/index.js
index 3dcacc5703..d81fd39281 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/attributes-aria/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/attributes-aria/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-attributes-aria';
 export { default } from 'x/attributes-aria';
-export * from 'x/attributes-aria';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all-alias/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all-alias/expected.html
index ffea7153d0..cb48579e82 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all-alias/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all-alias/expected.html
@@ -1,4 +1,4 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       getComponentDef
@@ -11,4 +11,4 @@
       renderComponent
     </div>
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all-alias/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all-alias/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all-alias/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all-alias/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all/expected.html
index ffea7153d0..cb48579e82 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all/expected.html
@@ -1,4 +1,4 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       getComponentDef
@@ -11,4 +11,4 @@
       renderComponent
     </div>
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-all/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-named/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-named/expected.html
index ffea7153d0..cb48579e82 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-named/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-named/expected.html
@@ -1,4 +1,4 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       getComponentDef
@@ -11,4 +11,4 @@
       renderComponent
     </div>
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-named/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-named/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-named/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/barrel-lwc-exports/export-named/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-basic/expected.html
index 7bf1562487..4a119a34b7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-basic/expected.html
@@ -1,8 +1,8 @@
-<x-comments-basic>
+<fixture-test>
   <template shadowrootmode="open">
     <!-- This is an HTML comment -->
     <button>
       click me
     </button>
   </template>
-</x-comments-basic>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-basic/index.js
index 7c3b99a842..9ed72ec5b9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-basic';
 export { default } from 'x/comments-basic';
-export * from 'x/comments-basic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-foreach/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-foreach/expected.html
index bc05045b0d..a1d6e51909 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-foreach/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-foreach/expected.html
@@ -1,4 +1,4 @@
-<x-comments-foreach>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <!-- color -->
@@ -15,4 +15,4 @@
       </li>
     </ul>
   </template>
-</x-comments-foreach>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-foreach/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-foreach/index.js
index e448189081..ab4909abdc 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-foreach/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-foreach/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-foreach';
 export { default } from 'x/comments-foreach';
-export * from 'x/comments-foreach';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-if/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-if/expected.html
index c94ed2ad96..5f0463a664 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-if/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-if/expected.html
@@ -1,8 +1,8 @@
-<x-comments-if>
+<fixture-test>
   <template shadowrootmode="open">
     <!-- HTML comment inside if:true -->
     <p>
       true branch
     </p>
   </template>
-</x-comments-if>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-if/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-if/index.js
index e28debea77..b1c5ed5ff7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-if/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-if/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-if';
 export { default } from 'x/comments-if';
-export * from 'x/comments-if';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-slot/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-slot/expected.html
index 590437d0ea..48cc3f8dc5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-slot/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-slot/expected.html
@@ -1,4 +1,4 @@
-<x-comments-slot>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -13,4 +13,4 @@
       </p>
     </x-child>
   </template>
-</x-comments-slot>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-slot/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-slot/index.js
index db8e9ca207..54e1c46bda 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-slot/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-slot/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-slot';
 export { default } from 'x/comments-slot';
-export * from 'x/comments-slot';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve-off/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve-off/expected.html
index 2373bd192b..80682ada84 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve-off/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve-off/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       text
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve-off/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve-off/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve-off/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve-off/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve/expected.html
index 2bd90962e1..0062e34b48 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve/expected.html
@@ -1,4 +1,4 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       ‍
@@ -6,4 +6,4 @@
       text
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/comments-text-preserve/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/component/expected.html
index 808d1ec6cc..73d0af7165 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/component/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -6,4 +6,4 @@
       </template>
     </x-child>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/component/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/computed/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/computed/expected.html
index 684d681396..566232e5c2 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/computed/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/computed/expected.html
@@ -1,5 +1,5 @@
-<x-computed>
+<fixture-test>
   <template shadowrootmode="open">
     7 + 3 = 10
   </template>
-</x-computed>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/computed/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/computed/index.js
index db6f0e1131..118f60cd9c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/computed/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/computed/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-computed';
 export { default } from 'x/computed';
-export * from 'x/computed';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-deep/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-deep/expected.html
index aff71baf5d..1af2702308 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-deep/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-deep/expected.html
@@ -1,4 +1,4 @@
-<x-provider>
+<fixture-test>
   <template shadowrootmode="open">
     <x-middle>
       <template shadowrootmode="open">
@@ -12,4 +12,4 @@
       </template>
     </x-middle>
   </template>
-</x-provider>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-deep/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-deep/index.js
index 94cb0e9241..1ff274646a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-deep/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-deep/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-provider';
 export { default } from 'x/provider';
-export * from 'x/provider';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-installation-on-non-element/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-installation-on-non-element/index.js
index 94cb0e9241..1ff274646a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-installation-on-non-element/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-installation-on-non-element/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-provider';
 export { default } from 'x/provider';
-export * from 'x/provider';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-nested/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-nested/expected.html
index 6d2dba7e10..d2151013a7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-nested/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-nested/expected.html
@@ -1,4 +1,4 @@
-<x-provider>
+<fixture-test>
   <template shadowrootmode="open">
     <x-provider-nested>
       <template shadowrootmode="open">
@@ -12,4 +12,4 @@
       </template>
     </x-provider-nested>
   </template>
-</x-provider>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-nested/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-nested/index.js
index 94cb0e9241..1ff274646a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-nested/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-nested/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-provider';
 export { default } from 'x/provider';
-export * from 'x/provider';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-no-provider/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-no-provider/expected.html
index b1a850f7a0..c74191994c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-no-provider/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-no-provider/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-consumer>
       <template shadowrootmode="open">
@@ -8,4 +8,4 @@
       </template>
     </x-consumer>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-no-provider/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-no-provider/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-no-provider/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-no-provider/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-shadowed/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-shadowed/expected.html
index 4fb623ce2b..4dd20d0947 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-shadowed/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-shadowed/expected.html
@@ -1,4 +1,4 @@
-<x-provider>
+<fixture-test>
   <template shadowrootmode="open">
     <x-middle>
       <template shadowrootmode="open">
@@ -12,4 +12,4 @@
       </template>
     </x-middle>
   </template>
-</x-provider>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-shadowed/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-shadowed/index.js
index 94cb0e9241..1ff274646a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-shadowed/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-shadowed/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-provider';
 export { default } from 'x/provider';
-export * from 'x/provider';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-method/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-method/expected.html
index 4ab67b81f5..e8350646e9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-method/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-method/expected.html
@@ -1,4 +1,4 @@
-<x-provider>
+<fixture-test>
   <template shadowrootmode="open">
     <x-consumer>
       <template shadowrootmode="open">
@@ -8,4 +8,4 @@
       </template>
     </x-consumer>
   </template>
-</x-provider>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-method/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-method/index.js
index 94cb0e9241..1ff274646a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-method/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-method/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-provider';
 export { default } from 'x/provider';
-export * from 'x/provider';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-setter/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-setter/expected.html
index 4ab67b81f5..e8350646e9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-setter/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-setter/expected.html
@@ -1,4 +1,4 @@
-<x-provider>
+<fixture-test>
   <template shadowrootmode="open">
     <x-consumer>
       <template shadowrootmode="open">
@@ -8,4 +8,4 @@
       </template>
     </x-consumer>
   </template>
-</x-provider>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-setter/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-setter/index.js
index 94cb0e9241..1ff274646a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-setter/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple-setter/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-provider';
 export { default } from 'x/provider';
-export * from 'x/provider';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple/expected.html
index 4ab67b81f5..e8350646e9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple/expected.html
@@ -1,4 +1,4 @@
-<x-provider>
+<fixture-test>
   <template shadowrootmode="open">
     <x-consumer>
       <template shadowrootmode="open">
@@ -8,4 +8,4 @@
       </template>
     </x-consumer>
   </template>
-</x-provider>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple/index.js
index 94cb0e9241..1ff274646a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-simple/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-provider';
 export { default } from 'x/provider';
-export * from 'x/provider';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/light/expected.html
index 61738a2a38..b1a089164c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/light/expected.html
@@ -1,4 +1,4 @@
-<x-root>
+<fixture-test>
   <x-provider>
     <!---->
     <x-consumer>
@@ -8,4 +8,4 @@
     </x-consumer>
     <!---->
   </x-provider>
-</x-root>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/light/index.js
index 64dd80573e..03f4f81873 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-root';
 export { default } from 'x/root';
-export * from 'x/root';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/scoped/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/scoped/expected.html
index a0c8f044b0..aab46dd9d1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/scoped/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/scoped/expected.html
@@ -1,4 +1,4 @@
-<x-root>
+<fixture-test>
   <x-provider>
     <!---->
     <!---->
@@ -13,4 +13,4 @@
     <!---->
     <!---->
   </x-provider>
-</x-root>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/scoped/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/scoped/index.js
index 64dd80573e..03f4f81873 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/scoped/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/scoped/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-root';
 export { default } from 'x/root';
-export * from 'x/root';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/shadow/expected.html
index e79e22387a..1574e41959 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-root>
+<fixture-test>
   <template shadowrootmode="open">
     <x-provider>
       <template shadowrootmode="open">
@@ -14,4 +14,4 @@
       </x-consumer>
     </x-provider>
   </template>
-</x-root>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/shadow/index.js
index 64dd80573e..03f4f81873 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/context-slotted/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-root';
 export { default } from 'x/root';
-export * from 'x/root';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/custom-styles-with-newlines/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/custom-styles-with-newlines/expected.html
index 57333c5180..e7c70fed4d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/custom-styles-with-newlines/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/custom-styles-with-newlines/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div style="
             color: blue;
@@ -6,4 +6,4 @@
         ">
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/custom-styles-with-newlines/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/custom-styles-with-newlines/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/custom-styles-with-newlines/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/custom-styles-with-newlines/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/decorator-api/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/decorator-api/expected.html
index 53018a4e26..ab2b9580e8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/decorator-api/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/decorator-api/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -17,4 +17,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/decorator-api/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/decorator-api/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/decorator-api/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/decorator-api/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/deeply-nested/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/deeply-nested/expected.html
index 33bead581c..3d698d3a25 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/deeply-nested/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/deeply-nested/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       <!---->
@@ -1228,4 +1228,4 @@
       <!---->
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/deeply-nested/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/deeply-nested/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/deeply-nested/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/deeply-nested/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/delegates-focus/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/delegates-focus/expected.html
index d775de0f19..c2bd7d0a60 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/delegates-focus/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/delegates-focus/expected.html
@@ -1,7 +1,7 @@
-<x-delegates-focus>
+<fixture-test>
   <template shadowrootdelegatesfocus shadowrootmode="open">
     <button>
       Focus!
     </button>
   </template>
-</x-delegates-focus>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/delegates-focus/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/delegates-focus/index.js
index d90fdecef1..98ce8965bd 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/delegates-focus/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/delegates-focus/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-delegates-focus';
 export { default } from 'x/delegates-focus';
-export * from 'x/delegates-focus';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/directive-external/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/directive-external/expected.html
index c7e30c481b..4172117aa7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/directive-external/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/directive-external/expected.html
@@ -1,4 +1,4 @@
-<x-test>
+<fixture-test>
   <template shadowrootmode="open">
     <x-hello>
       <template shadowrootmode="open">
@@ -18,4 +18,4 @@
     <foo-bar bar="configured bar" foo="configured foo">
     </foo-bar>
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/directive-external/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/directive-external/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/directive-external/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/directive-external/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/light/expected.html
index 120c3cbe3c..33bdaf58dd 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     a
     <!---->
@@ -20,4 +20,4 @@
     <!---->
     d
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/shadow/expected.html
index 7296bb8ba4..386172f0eb 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -18,4 +18,4 @@
       </div>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/duplicate-slots-in-template/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/expected.html
index d8359986f8..bcd10dd4c3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/expected.html
@@ -1,9 +1,9 @@
-<x-dynamic-component>
+<fixture-test>
   <template shadowrootmode="open">
-    <x-test>
+    <x-static>
       <template shadowrootmode="open">
         Test dynamic component!
       </template>
-    </x-test>
+    </x-static>
   </template>
-</x-dynamic-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/index.js
index 3b52a8cf57..17572b381f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component';
 export { default } from 'x/dynamic';
-export * from 'x/dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/dynamic/dynamic.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/dynamic/dynamic.js
index d051bccad0..147da3fe89 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/dynamic/dynamic.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/dynamic/dynamic.js
@@ -1,5 +1,5 @@
 import { LightningElement, track } from 'lwc';
-import Test from 'x/test';
+import Test from 'x/static';
 
 export default class DynamicCtor extends LightningElement {
     @track customCtor = Test;
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/test/test.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/static/static.html
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/test/test.html
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/static/static.html
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/test/test.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/static/static.js
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/test/test.js
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/basic/modules/x/static/static.js
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/invalid-ctor-function/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/invalid-ctor-function/index.js
index 0fdf153b63..c9589ae983 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/invalid-ctor-function/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/invalid-ctor-function/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component-invalid-ctor';
 export { default } from 'x/dynamic-invalid-ctor';
-export * from 'x/dynamic-invalid-ctor';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/invalid-ctor/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/invalid-ctor/index.js
index 0fdf153b63..c9589ae983 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/invalid-ctor/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/invalid-ctor/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component-invalid-ctor';
 export { default } from 'x/dynamic-invalid-ctor';
-export * from 'x/dynamic-invalid-ctor';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/expected.html
index 219a8931a2..1060ad88fe 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/expected.html
@@ -1,14 +1,14 @@
-<x-dynamic-component>
+<fixture-test>
   <template shadowrootmode="open">
-    <x-test>
+    <x-static>
       <template shadowrootmode="open">
         Test dynamic component!
       </template>
-    </x-test>
-    <x-test>
+    </x-static>
+    <x-static>
       <template shadowrootmode="open">
         Test dynamic component!
       </template>
-    </x-test>
+    </x-static>
   </template>
-</x-dynamic-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/index.js
index 3b52a8cf57..17572b381f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component';
 export { default } from 'x/dynamic';
-export * from 'x/dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/dynamic/dynamic.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/dynamic/dynamic.html
index bb7c0eb1d9..9539ed4ea4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/dynamic/dynamic.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/dynamic/dynamic.html
@@ -1,4 +1,4 @@
 <template>
-    <x-test></x-test>
+    <x-static></x-static>
     <lwc:component lwc:is={customCtor}></lwc:component>
 </template>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/dynamic/dynamic.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/dynamic/dynamic.js
index d051bccad0..147da3fe89 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/dynamic/dynamic.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/dynamic/dynamic.js
@@ -1,5 +1,5 @@
 import { LightningElement, track } from 'lwc';
-import Test from 'x/test';
+import Test from 'x/static';
 
 export default class DynamicCtor extends LightningElement {
     @track customCtor = Test;
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/test/test.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/static/static.html
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/test/test.html
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/static/static.html
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/test/test.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/static/static.js
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/test/test.js
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/mixed/modules/x/static/static.js
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/no-ctor/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/no-ctor/expected.html
index d8fbe3c1a0..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/no-ctor/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/no-ctor/expected.html
@@ -1,4 +1,4 @@
-<x-dynamic-component-no-ctor>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-dynamic-component-no-ctor>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/no-ctor/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/no-ctor/index.js
index 4504931f55..32902605b1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/no-ctor/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/no-ctor/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component-no-ctor';
 export { default } from 'x/dynamic-no-ctor';
-export * from 'x/dynamic-no-ctor';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/scoped-styles/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/scoped-styles/expected.html
index 2f6716c113..dfefb7b229 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/scoped-styles/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/scoped-styles/expected.html
@@ -1,4 +1,4 @@
-<x-dynamic-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-scoped-style class="lwc-2d8pgjj85pu-host" data-lwc-host-scope-token="lwc-2d8pgjj85pu-host">
       <template shadowrootmode="open">
@@ -12,4 +12,4 @@
       </template>
     </x-scoped-style>
   </template>
-</x-dynamic-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/scoped-styles/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/scoped-styles/index.js
index 3b52a8cf57..17572b381f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/scoped-styles/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/scoped-styles/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component';
 export { default } from 'x/dynamic';
-export * from 'x/dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/expected.html
index 886d6dc1d4..dd4c388de9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/expected.html
@@ -1,11 +1,11 @@
-<x-dynamic-component>
+<fixture-test>
   <template shadowrootmode="open">
-    <x-test>
+    <x-static>
       a
       <!---->
       fallback
       <!---->
       b
-    </x-test>
+    </x-static>
   </template>
-</x-dynamic-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/index.js
index 3b52a8cf57..17572b381f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component';
 export { default } from 'x/dynamic';
-export * from 'x/dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/dynamic/dynamic.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/dynamic/dynamic.js
index d051bccad0..147da3fe89 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/dynamic/dynamic.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/dynamic/dynamic.js
@@ -1,5 +1,5 @@
 import { LightningElement, track } from 'lwc';
-import Test from 'x/test';
+import Test from 'x/static';
 
 export default class DynamicCtor extends LightningElement {
     @track customCtor = Test;
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/test/test.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/static/static.html
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/test/test.html
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/static/static.html
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/test/test.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/static/static.js
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/test/test.js
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light-fallback/modules/x/static/static.js
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/expected.html
index de8cba90f3..efee4342f5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/expected.html
@@ -1,6 +1,6 @@
-<x-dynamic-component>
+<fixture-test>
   <template shadowrootmode="open">
-    <x-test>
+    <x-static>
       a
       <!---->
       <div>
@@ -8,6 +8,6 @@
       </div>
       <!---->
       b
-    </x-test>
+    </x-static>
   </template>
-</x-dynamic-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/index.js
index 3b52a8cf57..17572b381f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component';
 export { default } from 'x/dynamic';
-export * from 'x/dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/dynamic/dynamic.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/dynamic/dynamic.js
index d051bccad0..147da3fe89 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/dynamic/dynamic.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/dynamic/dynamic.js
@@ -1,5 +1,5 @@
 import { LightningElement, track } from 'lwc';
-import Test from 'x/test';
+import Test from 'x/static';
 
 export default class DynamicCtor extends LightningElement {
     @track customCtor = Test;
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/test/test.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/static/static.html
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/test/test.html
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/static/static.html
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/test/test.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/static/static.js
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/test/test.js
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/light/modules/x/static/static.js
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/expected.html
index 8f4236b230..3183e007e8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/expected.html
@@ -1,6 +1,6 @@
-<x-dynamic-component>
+<fixture-test>
   <template shadowrootmode="open">
-    <x-test>
+    <x-static>
       a
       <!---->
       <!---->
@@ -10,6 +10,6 @@
       <!---->
       <!---->
       b
-    </x-test>
+    </x-static>
   </template>
-</x-dynamic-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/index.js
index 3b52a8cf57..17572b381f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component';
 export { default } from 'x/dynamic';
-export * from 'x/dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/dynamic/dynamic.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/dynamic/dynamic.js
index d051bccad0..147da3fe89 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/dynamic/dynamic.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/dynamic/dynamic.js
@@ -1,5 +1,5 @@
 import { LightningElement, track } from 'lwc';
-import Test from 'x/test';
+import Test from 'x/static';
 
 export default class DynamicCtor extends LightningElement {
     @track customCtor = Test;
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/test/test.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/static/static.html
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/test/test.html
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/static/static.html
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/test/test.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/static/static.js
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/test/test.js
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/scoped-slots/modules/x/static/static.js
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/expected.html
index b080fb15c5..a648322ab6 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/expected.html
@@ -1,6 +1,6 @@
-<x-dynamic-component>
+<fixture-test>
   <template shadowrootmode="open">
-    <x-test>
+    <x-static>
       <template shadowrootmode="open">
         a
         <slot>
@@ -11,6 +11,6 @@
       <div>
         Slot me in!
       </div>
-    </x-test>
+    </x-static>
   </template>
-</x-dynamic-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/index.js
index 3b52a8cf57..17572b381f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component';
 export { default } from 'x/dynamic';
-export * from 'x/dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/dynamic/dynamic.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/dynamic/dynamic.js
index d051bccad0..147da3fe89 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/dynamic/dynamic.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/dynamic/dynamic.js
@@ -1,5 +1,5 @@
 import { LightningElement, track } from 'lwc';
-import Test from 'x/test';
+import Test from 'x/static';
 
 export default class DynamicCtor extends LightningElement {
     @track customCtor = Test;
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/test/test.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/static/static.html
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/test/test.html
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/static/static.html
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/test/test.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/static/static.js
similarity index 100%
rename from packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/test/test.js
rename to packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-components/slots/shadow/modules/x/static/static.js
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-imports/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-imports/basic/expected.html
index 1b5e90b198..c10e8f1319 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-imports/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-imports/basic/expected.html
@@ -1,5 +1,5 @@
-<x-dynamic-component>
+<fixture-test>
   <template shadowrootmode="open">
     Importee: 
   </template>
-</x-dynamic-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-imports/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-imports/basic/index.js
index 3b52a8cf57..17572b381f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-imports/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-imports/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dynamic-component';
 export { default } from 'x/dynamic';
-export * from 'x/dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-slots/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-slots/expected.html
index 5ee62d5630..e65d512c76 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-slots/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-slots/expected.html
@@ -1,4 +1,4 @@
-<x-slots>
+<fixture-test>
   <template shadowrootmode="open">
     <x-receiver>
       <template shadowrootmode="open">
@@ -28,4 +28,4 @@
       G
     </x-receiver>
   </template>
-</x-slots>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-slots/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-slots/index.js
index ef585717fe..bcedbda48e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-slots/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/dynamic-slots/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-slots';
 export { default } from 'x/slots';
-export * from 'x/slots';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/empty-text-with-comments-non-static-optimized/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/empty-text-with-comments-non-static-optimized/expected.html
index 2373bd192b..80682ada84 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/empty-text-with-comments-non-static-optimized/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/empty-text-with-comments-non-static-optimized/expected.html
@@ -1,7 +1,7 @@
-<x-comments-text>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
       text
     </span>
   </template>
-</x-comments-text>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/empty-text-with-comments-non-static-optimized/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/empty-text-with-comments-non-static-optimized/index.js
index 4bd94488e9..b89d321c27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/empty-text-with-comments-non-static-optimized/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/empty-text-with-comments-non-static-optimized/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-comments-text';
 export { default } from 'x/comments-text';
-export * from 'x/comments-text';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/component-as-default/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/component-as-default/expected.html
index 1dd9a11014..1800c82fec 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/component-as-default/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/component-as-default/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-shadow>
       <template shadowrootmode="open">
@@ -16,4 +16,4 @@ <h1>
     <x-light>
     </x-light>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/component-as-default/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/component-as-default/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/component-as-default/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/component-as-default/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-named/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-named/expected.html
index 1e9fcc7096..1f367c97a0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-named/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-named/expected.html
@@ -1,5 +1,5 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
     As the children proclaim, you only live once!
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-named/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-named/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-named/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-named/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-unnamed/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-unnamed/expected.html
index 1e9fcc7096..1f367c97a0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-unnamed/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-unnamed/expected.html
@@ -1,5 +1,5 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
     As the children proclaim, you only live once!
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-unnamed/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-unnamed/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-unnamed/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-class-unnamed/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-identifier/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-identifier/expected.html
index 1e9fcc7096..1f367c97a0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-identifier/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-identifier/expected.html
@@ -1,5 +1,5 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
     As the children proclaim, you only live once!
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-identifier/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-identifier/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-identifier/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/exports/default-identifier/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/face-callback/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/face-callback/expected.html
index 039b0f6aa2..80b13f88d0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/face-callback/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/face-callback/expected.html
@@ -1,4 +1,4 @@
-<face-container>
+<fixture-test>
   <template shadowrootmode="open">
     <form>
       <face-control>
@@ -11,4 +11,4 @@
       </face-control>
     </form>
   </template>
-</face-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/face-callback/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/face-callback/index.js
index 05baaca494..782828c589 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/face-callback/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/face-callback/index.js
@@ -1,3 +1 @@
-export const tagName = 'face-container';
 export { default } from 'face/container';
-export * from 'face/container';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/basic/expected.html
index 4953a27813..3b62ecf650 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/basic/expected.html
@@ -1,4 +1,4 @@
-<x-for-each-block>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <li>
@@ -12,4 +12,4 @@
       </li>
     </ul>
   </template>
-</x-for-each-block>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/basic/index.js
index 56055e6ebf..086512800a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-for-each-block';
 export { default } from 'x/for-each-block';
-export * from 'x/for-each-block';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/child-nested/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/child-nested/expected.html
index eebd34fac8..e8e465b996 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/child-nested/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/child-nested/expected.html
@@ -1,4 +1,4 @@
-<x-for-each-child-nested>
+<fixture-test>
   <template shadowrootmode="open">
     <ol>
       <li>
@@ -35,4 +35,4 @@
       </li>
     </ol>
   </template>
-</x-for-each-child-nested>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/child-nested/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/child-nested/index.js
index 06de211808..f0d37e93f0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/child-nested/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/child-nested/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-for-each-child-nested';
 export { default } from 'x/for-each-child-nested';
-export * from 'x/for-each-child-nested';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/item-and-index/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/item-and-index/expected.html
index 8e5795078d..48a83d174c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/item-and-index/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/item-and-index/expected.html
@@ -1,4 +1,4 @@
-<x-container>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <li data-index="0" data-item="one">
@@ -33,4 +33,4 @@
       </x-child>
     </ul>
   </template>
-</x-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/item-and-index/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/item-and-index/index.js
index 9763122105..420d88855d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/item-and-index/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/item-and-index/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-container';
 export { default } from 'x/container';
-export * from 'x/container';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/nested/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/nested/expected.html
index 2db1a43d3c..7146209687 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/nested/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/nested/expected.html
@@ -1,4 +1,4 @@
-<x-for-each-nested>
+<fixture-test>
   <template shadowrootmode="open">
     <ol>
       <li>
@@ -31,4 +31,4 @@
       </li>
     </ol>
   </template>
-</x-for-each-nested>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/nested/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/nested/index.js
index fa09c22291..a3671cb667 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/nested/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/nested/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-for-each-nested';
 export { default } from 'x/for-each-nested';
-export * from 'x/for-each-nested';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/static-content/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/static-content/expected.html
index 1654df27d0..df5c6d76d7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/static-content/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/static-content/expected.html
@@ -1,4 +1,4 @@
-<x-container>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <li>
@@ -27,4 +27,4 @@
       </li>
     </ul>
   </template>
-</x-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/static-content/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/static-content/index.js
index 9763122105..420d88855d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/static-content/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/for-each-block/static-content/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-container';
 export { default } from 'x/container';
-export * from 'x/container';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list-noop/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list-noop/expected.html
index 4593cc3fb9..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list-noop/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list-noop/expected.html
@@ -1,4 +1,4 @@
-<x-getter-class-list-noop>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-getter-class-list-noop>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list-noop/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list-noop/index.js
index a0d56c0d92..f5cfa3216c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list-noop/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list-noop/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-getter-class-list-noop';
 export { default } from 'x/getter-class-list-noop';
-export * from 'x/getter-class-list-noop';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list/expected.html
index f5e5d8382b..90de4ea7d5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list/expected.html
@@ -1,4 +1,4 @@
-<x-getter-class-list class="a c d-e" data-lwc-host-mutated="class">
+<fixture-test class="a c d-e" data-lwc-host-mutated="class">
   <template shadowrootmode="open">
   </template>
-</x-getter-class-list>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list/index.js
index 1caea43648..922308b8ee 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-class-list/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-getter-class-list';
 export { default } from 'x/getter-class-list';
-export * from 'x/getter-class-list';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-is-connected/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-is-connected/expected.html
index 6a91b448ed..20ce408769 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-is-connected/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-is-connected/expected.html
@@ -1,4 +1,4 @@
-<x-getter-is-connected>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <li>
@@ -12,4 +12,4 @@
       </li>
     </ul>
   </template>
-</x-getter-is-connected>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-is-connected/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-is-connected/index.js
index e2d5754198..e10ea9bd5c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/getter-is-connected/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/getter-is-connected/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-getter-is-connected';
 export { default } from 'x/getter-is-connected';
-export * from 'x/getter-is-connected';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/global-html-attributes/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/global-html-attributes/expected.html
index 887da4a64a..d403bb2fc9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/global-html-attributes/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/global-html-attributes/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child accesskey="tata" aria-label="titi" dir="auto" draggable="false" id="tutu" lang="jp" role="scrollbar" spellcheck="false" tabindex="0" title="tete">
       <template shadowrootmode="open">
@@ -75,4 +75,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/global-html-attributes/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/global-html-attributes/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/global-html-attributes/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/global-html-attributes/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-connected-callback/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-connected-callback/expected.html
index 73bc33918f..9eef69a575 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-connected-callback/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-connected-callback/expected.html
@@ -1,4 +1,4 @@
-<x-test data-lwc-host-mutated="data-mutated-in-connected-callback" data-mutated-in-connected-callback="true">
+<fixture-test data-lwc-host-mutated="data-mutated-in-connected-callback" data-mutated-in-connected-callback="true">
   <template shadowrootmode="open">
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-connected-callback/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-connected-callback/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-connected-callback/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-connected-callback/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-render/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-render/expected.html
index c09bc5e40a..5bc9098172 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-render/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-render/expected.html
@@ -1,4 +1,4 @@
-<x-test data-mutated-in-render="true">
+<fixture-test data-mutated-in-render="true">
   <template shadowrootmode="open">
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-render/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-render/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-render/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/host-mutate-in-render/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-block/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/if-block/expected.html
index 6ea75c1383..696215dd5e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-block/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-block/expected.html
@@ -1,4 +1,4 @@
-<x-if-block>
+<fixture-test>
   <template shadowrootmode="open">
     <h1>
       True!
@@ -19,4 +19,4 @@ <h1>
       I am rendered because I am untrustworthy!
     </p>
   </template>
-</x-if-block>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-block/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/if-block/index.js
index cf5b2db0fe..f2db46f1b7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-block/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-block/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-if-block';
 export { default } from 'x/if-block';
-export * from 'x/if-block';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot-content/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot-content/expected.html
index 1347291394..38907a86c8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot-content/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot-content/expected.html
@@ -1,4 +1,4 @@
-<x-if-conditional-slot-content>
+<fixture-test>
   <template shadowrootmode="open">
     <div class="active-if-blocks">
       <x-conditional-slot-content>
@@ -53,4 +53,4 @@
       </x-conditional-slot-content>
     </div>
   </template>
-</x-if-conditional-slot-content>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot-content/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot-content/index.js
index 9988f09501..c4f41234d8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot-content/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot-content/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-if-conditional-slot-content';
 export { default } from 'x/if-conditional-slot-content';
-export * from 'x/if-conditional-slot-content';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot/expected.html
index c47a21c4f3..bd8cb460e0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot/expected.html
@@ -1,4 +1,4 @@
-<x-if-conditional-slot>
+<fixture-test>
   <template shadowrootmode="open">
     <div class="active-if-blocks">
       <x-parent>
@@ -55,4 +55,4 @@
       </x-parent>
     </div>
   </template>
-</x-if-conditional-slot>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot/index.js
index cd48a8f718..1ff6771dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-conditional-slot/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-if-conditional-slot';
 export { default } from 'x/if-conditional-slot';
-export * from 'x/if-conditional-slot';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-custom-element-child/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/if-custom-element-child/expected.html
index 99c71e4217..f9413c1632 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-custom-element-child/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-custom-element-child/expected.html
@@ -1,4 +1,4 @@
-<x-if-custom-element-child>
+<fixture-test>
   <template shadowrootmode="open">
     <div class="active-if-blocks">
       <x-custom-element-child>
@@ -23,4 +23,4 @@
       </x-custom-element-child>
     </div>
   </template>
-</x-if-custom-element-child>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-custom-element-child/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/if-custom-element-child/index.js
index 3bb1eefb24..2d553ade29 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-custom-element-child/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-custom-element-child/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-if-custom-element-child';
 export { default } from 'x/if-custom-element-child';
-export * from 'x/if-custom-element-child';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-element-child/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/if-element-child/expected.html
index 7410b9a455..3963fb84ef 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-element-child/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-element-child/expected.html
@@ -1,4 +1,4 @@
-<x-if-element-child>
+<fixture-test>
   <template shadowrootmode="open">
     <div class="active-if-blocks">
       <x-element-child>
@@ -17,4 +17,4 @@
       </x-element-child>
     </div>
   </template>
-</x-if-element-child>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-element-child/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/if-element-child/index.js
index ea637943bd..1283080298 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-element-child/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-element-child/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-if-element-child';
 export { default } from 'x/if-element-child';
-export * from 'x/if-element-child';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-false/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-false/expected.html
index 7e141df075..122bb6ec50 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-false/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-false/expected.html
@@ -1,8 +1,8 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       No HTML bookend comments should render below:
     </div>
     I am rendered.
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-false/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-false/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-false/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-false/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-true/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-true/expected.html
index 7e141df075..122bb6ec50 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-true/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-true/expected.html
@@ -1,8 +1,8 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       No HTML bookend comments should render below:
     </div>
     I am rendered.
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-true/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-true/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-true/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/if-true-if-true/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/import-lwc-from-helper/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/import-lwc-from-helper/expected.html
index ce996e78e1..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/import-lwc-from-helper/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/import-lwc-from-helper/expected.html
@@ -1,4 +1,4 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/import-lwc-from-helper/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/import-lwc-from-helper/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/import-lwc-from-helper/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/import-lwc-from-helper/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/inner-outer-html/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/inner-outer-html/expected.html
index 552399789e..71d253a4fd 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/inner-outer-html/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/inner-outer-html/expected.html
@@ -1,4 +1,4 @@
-<x-inner>
+<fixture-test>
   <template shadowrootmode="open">
     <div data-expect-no-warning data-id="div-inner-static" inner-h-t-m-l="replaced">
       original
@@ -85,4 +85,4 @@
       injected
     </p>
   </template>
-</x-inner>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/inner-outer-html/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/inner-outer-html/index.js
index 278d09e0d3..7a176769c5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/inner-outer-html/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/inner-outer-html/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-inner';
 export { default } from 'x/inner';
-export * from 'x/inner';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/basic/expected.html
index d9dff3a59f..dc7f04f210 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/basic/expected.html
@@ -1,4 +1,4 @@
-<x-iterator-block>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <li>
@@ -16,4 +16,4 @@
       </li>
     </ul>
   </template>
-</x-iterator-block>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/basic/index.js
index 8538f1b9e7..7e4a134f61 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-iterator-block';
 export { default } from 'x/iterator-block';
-export * from 'x/iterator-block';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/missing-value/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/missing-value/expected.html
index 7290bb2ca4..55d60d841d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/missing-value/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/missing-value/expected.html
@@ -1,6 +1,6 @@
-<x-iterator-block>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
     </ul>
   </template>
-</x-iterator-block>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/missing-value/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/missing-value/index.js
index 8538f1b9e7..7e4a134f61 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/missing-value/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/missing-value/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-iterator-block';
 export { default } from 'x/iterator-block';
-export * from 'x/iterator-block';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/multiple/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/multiple/expected.html
index bd899daeee..35087ef51d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/multiple/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/multiple/expected.html
@@ -1,4 +1,4 @@
-<x-iterator-block>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <li>
@@ -29,4 +29,4 @@
       </li>
     </ul>
   </template>
-</x-iterator-block>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/multiple/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/multiple/index.js
index 8538f1b9e7..7e4a134f61 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/multiple/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/multiple/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-iterator-block';
 export { default } from 'x/iterator-block';
-export * from 'x/iterator-block';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/variables/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/variables/expected.html
index e3ddeb9697..9f9dfacfc8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/variables/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/variables/expected.html
@@ -1,4 +1,4 @@
-<x-container>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <li data-first="true" data-index="0" data-item="one" data-last="false">
@@ -33,4 +33,4 @@
       </x-child>
     </ul>
   </template>
-</x-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/variables/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/variables/index.js
index 9763122105..420d88855d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/variables/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/iterator-block/variables/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-container';
 export { default } from 'x/container';
-export * from 'x/container';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/boolean-true/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/boolean-true/expected.html
index 0e31e08c9c..4f35d8fd25 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/boolean-true/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/boolean-true/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <button autofocus>
     </button>
@@ -54,4 +54,4 @@
     <option selected>
     </option>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/boolean-true/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/boolean-true/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/boolean-true/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/boolean-true/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/dynamic/expected.html
index 717b8d9ff7..9969cddef5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -742,4 +742,4 @@
       </template>
     </x-child>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/dynamic/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/empty-string/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/empty-string/expected.html
index 0e31e08c9c..4f35d8fd25 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/empty-string/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/empty-string/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <button autofocus>
     </button>
@@ -54,4 +54,4 @@
     <option selected>
     </option>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/empty-string/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/empty-string/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/empty-string/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/empty-string/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/invalid-string/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/invalid-string/expected.html
index 4f5e1ea5fc..f816172ec4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/invalid-string/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/invalid-string/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <button autofocus="yolo">
     </button>
@@ -54,4 +54,4 @@
     <option selected="yolo">
     </option>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/invalid-string/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/invalid-string/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/invalid-string/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/invalid-string/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-false-uppercase/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-false-uppercase/expected.html
index 96a1a10d9c..2cbdf0ef9b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-false-uppercase/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-false-uppercase/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <button autofocus="FALSE">
     </button>
@@ -54,4 +54,4 @@
     <option selected="FALSE">
     </option>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-false-uppercase/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-false-uppercase/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-false-uppercase/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-false-uppercase/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-true-uppercase/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-true-uppercase/expected.html
index 1d42e088cd..88fcb9f96c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-true-uppercase/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-true-uppercase/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <button autofocus="TRUE">
     </button>
@@ -54,4 +54,4 @@
     <option selected="TRUE">
     </option>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-true-uppercase/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-true-uppercase/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-true-uppercase/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/correct-tag-attr-pair/string-true-uppercase/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/dynamic/expected.html
index e4c64f9cbb..46845ee6b8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -265,4 +265,4 @@
       </template>
     </x-child>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/dynamic/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static-on-component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static-on-component/expected.html
index 818c539306..477f7b3815 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static-on-component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static-on-component/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child tabindex="0">
       <template shadowrootmode="open">
@@ -253,4 +253,4 @@
       </template>
     </x-child>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static-on-component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static-on-component/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static-on-component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static-on-component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static/expected.html
index fa6f053c19..c0ea8b5f98 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div tabindex="0">
     </div>
@@ -127,4 +127,4 @@
     <div title="yolo">
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/default-def-html-attributes/static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/dynamic/expected.html
index 889f72718c..274f401aaa 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -105,4 +105,4 @@
       </template>
     </x-child>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/dynamic/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/static/expected.html
index 1559392ada..2ad884c631 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/static/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div autofocus>
     </div>
@@ -33,4 +33,4 @@
     <div formnovalidate="yolo">
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/static/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/incorrect-tag-attr-pair/static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/dynamic/expected.html
index fd924266f1..a156421951 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <input type="checkbox">
     <input type="checkbox">
@@ -40,4 +40,4 @@
     <input disabled>
     <input disabled>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/dynamic/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/static/expected.html
index 46503f62e8..1b96cbb581 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/static/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <input>
     <input type="checkbox">
@@ -21,4 +21,4 @@
     <input disabled="TRUE">
     <input disabled="yolo">
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/static/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/input/static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/spellcheck/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/spellcheck/expected.html
index 33d9eed3b6..10b95dbe27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/spellcheck/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/spellcheck/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <textarea spellcheck>
     </textarea>
@@ -43,4 +43,4 @@
     <textarea spellcheck="[object Object]">
     </textarea>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/spellcheck/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/spellcheck/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/spellcheck/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/known-boolean-attributes/spellcheck/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lifecycle-hooks/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lifecycle-hooks/expected.html
index e25ebd0360..836c7dacc3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lifecycle-hooks/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lifecycle-hooks/expected.html
@@ -1,4 +1,4 @@
-<x-lifecycle-hooks>
+<fixture-test>
   <template shadowrootmode="open">
     <ul>
       <li>
@@ -21,4 +21,4 @@
       </li>
     </ul>
   </template>
-</x-lifecycle-hooks>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lifecycle-hooks/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lifecycle-hooks/index.js
index 638976a6c8..2138107608 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lifecycle-hooks/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lifecycle-hooks/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-lifecycle-hooks';
 export { default } from 'x/lifecycle-hooks';
-export * from 'x/lifecycle-hooks';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-multiple/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-multiple/expected.html
index 755a99f732..9a46184615 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-multiple/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-multiple/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <style type="text/css">
     p {background-color: blue;}
   </style>
@@ -24,4 +24,4 @@
       two
     </p>
   </x-two>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-multiple/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-multiple/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-multiple/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-multiple/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles-render/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles-render/expected.html
index ee65d460a4..1ec13e9483 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles-render/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles-render/expected.html
@@ -1,8 +1,8 @@
-<x-basic class="lwc-7q48250iir7-host" data-lwc-host-scope-token="lwc-7q48250iir7-host">
+<fixture-test class="lwc-7q48250iir7-host" data-lwc-host-scope-token="lwc-7q48250iir7-host">
   <style class="lwc-7q48250iir7" type="text/css">
     p.lwc-7q48250iir7 {background-color: blue;}
   </style>
   <p class="lwc-7q48250iir7">
     Hello
   </p>
-</x-basic>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles-render/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles-render/index.js
index 12a4de763d..2dac65f07e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles-render/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles-render/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-basic';
 export { default } from 'x/basic';
-export * from 'x/basic';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles/expected.html
index ec51b4b24d..654e01cac5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles/expected.html
@@ -1,4 +1,4 @@
-<x-basic class="lwc-1rssj1tib70-host" data-lwc-host-scope-token="lwc-1rssj1tib70-host">
+<fixture-test class="lwc-1rssj1tib70-host" data-lwc-host-scope-token="lwc-1rssj1tib70-host">
   <style class="lwc-1rssj1tib70" type="text/css">
     p {color: red;}
   </style>
@@ -8,4 +8,4 @@
   <p class="lwc-1rssj1tib70">
     Hello
   </p>
-</x-basic>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles/index.js
index 12a4de763d..2dac65f07e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-scoped-styles/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-basic';
 export { default } from 'x/basic';
-export * from 'x/basic';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-styles-dir-host/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-styles-dir-host/expected.html
index 2582dc7578..c45678dcfb 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-styles-dir-host/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-styles-dir-host/expected.html
@@ -1,4 +1,4 @@
-<x-basic class="lwc-1rssj1tib70-host" data-lwc-host-scope-token="lwc-1rssj1tib70-host">
+<fixture-test class="lwc-1rssj1tib70-host" data-lwc-host-scope-token="lwc-1rssj1tib70-host">
   <style class="lwc-1rssj1tib70" type="text/css">
      :dir(rtl) {margin-left: 0;}:host {color: red;}
   </style>
@@ -8,4 +8,4 @@
   <p class="lwc-1rssj1tib70">
     Hello
   </p>
-</x-basic>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-styles-dir-host/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-styles-dir-host/index.js
index 12a4de763d..2dac65f07e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-styles-dir-host/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom-styles-dir-host/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-basic';
 export { default } from 'x/basic';
-export * from 'x/basic';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom/expected.html
index 8d6ef7570b..d72ea0fec5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom/expected.html
@@ -1,8 +1,8 @@
-<x-basic>
+<fixture-test>
   <style type="text/css">
     p {color: red;}
   </style>
   <p>
     Hello
   </p>
-</x-basic>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom/index.js
index ab7e62ac60..2dac65f07e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/light-dom/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-basic';
 export { default } from 'x/basic';
-export * from 'x/basic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dom-manual/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dom-manual/expected.html
index 3e03c16cb1..40c19b6eb1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dom-manual/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dom-manual/expected.html
@@ -1,6 +1,6 @@
-<x-lwc-dom-manual>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
     </div>
   </template>
-</x-lwc-dom-manual>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dom-manual/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dom-manual/index.js
index e4dc91e4cf..c14e3c6f97 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dom-manual/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dom-manual/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-lwc-dom-manual';
 export { default } from 'x/lwc-dom-manual';
-export * from 'x/lwc-dom-manual';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dynamic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dynamic/expected.html
index 7e9b2f20eb..d7302e32fa 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dynamic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dynamic/expected.html
@@ -1,4 +1,4 @@
-<x-lwc-dynamic>
+<fixture-test>
   <template shadowrootmode="open">
     <x-lazy>
       <template shadowrootmode="open">
@@ -6,4 +6,4 @@
       </template>
     </x-lazy>
   </template>
-</x-lwc-dynamic>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dynamic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dynamic/index.js
index 5a8c73b46f..f0b3ce5964 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dynamic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-dynamic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-lwc-dynamic';
 export { default } from 'x/lwc-dynamic';
-export * from 'x/lwc-dynamic';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else-empty/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else-empty/expected.html
index 8fecb48c25..8577ab91b5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else-empty/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else-empty/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       This should render a single pair of bookends with nothing inside:
@@ -6,4 +6,4 @@
     <!---->
     <!---->
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else-empty/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else-empty/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else-empty/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else-empty/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else/expected.html
index 922761b9c6..52c15e210d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <!---->
     I am rendered.
@@ -7,4 +7,4 @@
     Render me!
     <!---->
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if-else/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if/expected.html
index 283f940377..87706a9b26 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <!---->
     I am rendered.
     <!---->
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else-if/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else/expected.html
index d9dab77faa..3985fdcdf6 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <!---->
     I am true!
@@ -7,4 +7,4 @@
     I am not false!
     <!---->
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-else/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-no-content/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-no-content/expected.html
index 277942cd42..59b6b60c41 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-no-content/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-no-content/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     I should be followed by one set of empty bookend comments.
     <!---->
     <!---->
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-no-content/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-no-content/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-no-content/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if-no-content/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if/expected.html
index 735209f54b..24762200a7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <!---->
     I am rendered!
     <!---->
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-if/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-inner-html/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-inner-html/expected.html
index ad6411933a..ce4b1f0390 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-inner-html/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-inner-html/expected.html
@@ -1,4 +1,4 @@
-<x-lwc-inner-html>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Hello 
@@ -15,4 +15,4 @@
       </p>
     </div>
   </template>
-</x-lwc-inner-html>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-inner-html/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-inner-html/index.js
index eebc2088bc..b9a2d82ca1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-inner-html/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/lwc-inner-html/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-lwc-inner-html';
 export { default } from 'x/lwc-inner-html';
-export * from 'x/lwc-inner-html';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/method-get-attribute/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/method-get-attribute/expected.html
index ff1cb46676..94362dcf8c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/method-get-attribute/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/method-get-attribute/expected.html
@@ -1,4 +1,4 @@
-<x-method-get-attribute>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -22,4 +22,4 @@
       </template>
     </x-child>
   </template>
-</x-method-get-attribute>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/method-get-attribute/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/method-get-attribute/index.js
index a9a2abd99e..44764f569a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/method-get-attribute/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/method-get-attribute/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-method-get-attribute';
 export { default } from 'x/method-get-attribute';
-export * from 'x/method-get-attribute';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/method-remove-attribute/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/method-remove-attribute/expected.html
index 478484fac5..b4d065c699 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/method-remove-attribute/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/method-remove-attribute/expected.html
@@ -1,4 +1,4 @@
-<x-method-remove-attribute data-a data-c data-lwc-host-mutated="data-a data-b data-c data-unknown">
+<fixture-test data-a data-c data-lwc-host-mutated="data-a data-b data-c data-unknown">
   <template shadowrootmode="open">
   </template>
-</x-method-remove-attribute>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/method-remove-attribute/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/method-remove-attribute/index.js
index cbf50c664c..4def7c5a99 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/method-remove-attribute/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/method-remove-attribute/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-method-remove-attribute';
 export { default } from 'x/method-remove-attribute';
-export * from 'x/method-remove-attribute';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/method-set-attribute/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/method-set-attribute/expected.html
index 145ceae755..efd65a66b1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/method-set-attribute/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/method-set-attribute/expected.html
@@ -1,4 +1,4 @@
-<x-method-set-attribute data-boolean="true" data-empty-string data-lwc-host-mutated="data-boolean data-empty-string data-null data-number data-override data-string" data-null="null" data-number="1" data-override="override" data-string="test">
+<fixture-test data-boolean="true" data-empty-string data-lwc-host-mutated="data-boolean data-empty-string data-null data-number data-override data-string" data-null="null" data-number="1" data-override="override" data-string="test">
   <template shadowrootmode="open">
   </template>
-</x-method-set-attribute>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/method-set-attribute/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/method-set-attribute/index.js
index 773e7efabe..bafba24070 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/method-set-attribute/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/method-set-attribute/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-method-set-attribute';
 export { default } from 'x/method-set-attribute';
-export * from 'x/method-set-attribute';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/methods-noop/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/methods-noop/expected.html
index a81a8a56d1..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/methods-noop/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/methods-noop/expected.html
@@ -1,4 +1,4 @@
-<x-methods-noop>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-methods-noop>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/methods-noop/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/methods-noop/index.js
index f78b38fcb0..84295536ee 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/methods-noop/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/methods-noop/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-methods-noop';
 export { default } from 'x/methods-noop';
-export * from 'x/methods-noop';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/methods-unsupported/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/methods-unsupported/expected.html
index d37b0a5c46..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/methods-unsupported/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/methods-unsupported/expected.html
@@ -1,4 +1,4 @@
-<x-methods-unsupported>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-methods-unsupported>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/methods-unsupported/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/methods-unsupported/index.js
index 2351639dd9..5974214728 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/methods-unsupported/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/methods-unsupported/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-methods-unsupported';
 export { default } from 'x/methods-unsupported';
-export * from 'x/methods-unsupported';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-basic/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-child/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-child/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-child/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-child/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-deep-child/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-deep-child/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-deep-child/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-deep-child/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-slotted/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-slotted/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-slotted/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/no-boundary-protection-slotted/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/no-dup-styles/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/no-dup-styles/expected.html
index 8597e5d82c..24c8883195 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/no-dup-styles/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/no-dup-styles/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -15,4 +15,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/no-dup-styles/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/no-dup-styles/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/no-dup-styles/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/no-dup-styles/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/no-template/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/no-template/expected.html
index 5cdcad4479..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/no-template/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/no-template/expected.html
@@ -1,4 +1,4 @@
-<x-test>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/no-template/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/no-template/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/no-template/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/no-template/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/non-lwc-class/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/non-lwc-class/expected.html
index fc2d57cdb1..e43b6d1d62 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/non-lwc-class/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/non-lwc-class/expected.html
@@ -1,5 +1,5 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
     Value: foobar
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/non-lwc-class/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/non-lwc-class/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/non-lwc-class/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/non-lwc-class/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties-template/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties-template/expected.html
index d2cc0d66c4..397fe1c562 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties-template/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties-template/expected.html
@@ -1,4 +1,4 @@
-<x-overwrite-properties-template>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -32,4 +32,4 @@
       </template>
     </x-child>
   </template>
-</x-overwrite-properties-template>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties-template/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties-template/index.js
index a748786432..594a72df35 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties-template/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties-template/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-overwrite-properties-template';
 export { default } from 'x/overwrite-properties-template';
-export * from 'x/overwrite-properties-template';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties/expected.html
index 4664bc8e85..bea70a445b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties/expected.html
@@ -1,4 +1,4 @@
-<x-overwrite-properties>
+<fixture-test>
   <template shadowrootmode="open">
     <p>
       my name
@@ -28,4 +28,4 @@
       my event listeners
     </p>
   </template>
-</x-overwrite-properties>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties/index.js
index 0a74f4f2a0..a139b73e71 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/overwrite-properties/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-overwrite-properties';
 export { default } from 'x/overwrite-properties';
-export * from 'x/overwrite-properties';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/parent-child-connected-callback/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/parent-child-connected-callback/expected.html
index cdb5683c85..ff6ec31fb6 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/parent-child-connected-callback/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/parent-child-connected-callback/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       connectedCallback called
@@ -20,4 +20,4 @@
       </x-slotted>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/parent-child-connected-callback/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/parent-child-connected-callback/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/parent-child-connected-callback/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/parent-child-connected-callback/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/prohibited-variable-name/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/prohibited-variable-name/expected.html
index 3f43fcbd96..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/prohibited-variable-name/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/prohibited-variable-name/expected.html
@@ -1,4 +1,4 @@
-<x-dont-do-it-stupid>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-dont-do-it-stupid>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/prohibited-variable-name/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/prohibited-variable-name/index.js
index 14f1a20355..a46f16d7ca 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/prohibited-variable-name/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/prohibited-variable-name/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-dont-do-it-stupid';
 export { default } from 'x/dontDoItStupid';
-export * from 'x/dontDoItStupid';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/basic/expected.html
index 8553c35329..bdb5305296 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/basic/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -12,4 +12,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/basic/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/dynamic-child/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/dynamic-child/expected.html
index 8553c35329..bdb5305296 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/dynamic-child/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/dynamic-child/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -12,4 +12,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/dynamic-child/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/dynamic-child/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/dynamic-child/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/dynamic-child/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/pseudo-attribute/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/pseudo-attribute/expected.html
index fe862287af..fda8208582 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/pseudo-attribute/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/pseudo-attribute/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <template shadowrootmode="open">
@@ -12,4 +12,4 @@
       </template>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/pseudo-attribute/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/pseudo-attribute/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/pseudo-attribute/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/read-only-props/pseudo-attribute/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/attr-to-prop/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/attr-to-prop/expected.html
index 698ced6625..10da4fcc2b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/attr-to-prop/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/attr-to-prop/expected.html
@@ -1,4 +1,4 @@
-<x-test aria-current="connectedCallback" aria-label="connectedCallback" data-lwc-host-mutated="aria-current aria-label">
+<fixture-test aria-current="connectedCallback" aria-label="connectedCallback" data-lwc-host-mutated="aria-current aria-label">
   <template shadowrootmode="open">
     <div>
       ariaLabel: connectedCallback
@@ -7,4 +7,4 @@
       ariaCurrent: default property value for overridden ariaCurrent
     </div>
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/attr-to-prop/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/attr-to-prop/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/attr-to-prop/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/attr-to-prop/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/prop-to-attr/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/prop-to-attr/expected.html
index 4d41f7a6a8..d9dc4d70ad 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/prop-to-attr/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/prop-to-attr/expected.html
@@ -1,4 +1,4 @@
-<x-test aria-label="connectedCallback" data-lwc-host-mutated="aria-label">
+<fixture-test aria-label="connectedCallback" data-lwc-host-mutated="aria-label">
   <template shadowrootmode="open">
     <div>
       ariaLabel: connectedCallback
@@ -7,4 +7,4 @@
       ariaCurrent: connectedCallback
     </div>
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/prop-to-attr/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/prop-to-attr/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/prop-to-attr/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reflection/prop-to-attr/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/rehydration/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/rehydration/expected.html
index 9694de0907..c6d4d6044c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/rehydration/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/rehydration/expected.html
@@ -1,5 +1,5 @@
-<x-rehydration>
+<fixture-test>
   <template shadowrootmode="open">
     0
   </template>
-</x-rehydration>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/rehydration/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/rehydration/index.js
index cf080a7b53..6293943a4e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/rehydration/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/rehydration/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-rehydration';
 export { default } from 'x/rehydration';
-export * from 'x/rehydration';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-correct-tags/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-correct-tags/expected.html
index 862326ccfa..099aeea0e0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-correct-tags/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-correct-tags/expected.html
@@ -1,4 +1,4 @@
-<x-elements class="lwc-4q9u0sqsfc0-host" data-lwc-host-scope-token="lwc-4q9u0sqsfc0-host">
+<fixture-test class="lwc-4q9u0sqsfc0-host" data-lwc-host-scope-token="lwc-4q9u0sqsfc0-host">
   <template shadowrootmode="open">
     <style class="lwc-4q9u0sqsfc0" type="text/css">
       :host {background: blue;}
@@ -36,4 +36,4 @@
       <image class="lwc-4q9u0sqsfc0" xlink:title="title"/>
     </svg>
   </template>
-</x-elements>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-correct-tags/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-correct-tags/index.js
index 99eaa6cf88..1298e3ad67 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-correct-tags/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-correct-tags/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-elements';
 export { default } from 'x/elements';
-export * from 'x/elements';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-dynamic-value/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-dynamic-value/expected.html
index a6d0a48fdf..f30b77534b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-dynamic-value/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-dynamic-value/expected.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       ‍
@@ -46,4 +46,4 @@
       6.02214076e+23
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-dynamic-value/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-dynamic-value/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-dynamic-value/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-dynamic-value/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-light-component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-light-component/expected.html
index 10501286b5..ccc2af9120 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-light-component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-light-component/expected.html
@@ -1,2 +1,2 @@
-<x-test>
-</x-test>
\ No newline at end of file
+<fixture-test>
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-light-component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-light-component/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-light-component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-light-component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-shadow-component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-shadow-component/expected.html
index 5cdcad4479..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-shadow-component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-shadow-component/expected.html
@@ -1,4 +1,4 @@
-<x-test>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-shadow-component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-shadow-component/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-shadow-component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/default-template-shadow-component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-default-component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-default-component/expected.html
index 5cdcad4479..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-default-component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-default-component/expected.html
@@ -1,4 +1,4 @@
-<x-test>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-default-component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-default-component/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-default-component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-default-component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-shadow-component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-shadow-component/expected.html
index 5cdcad4479..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-shadow-component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-shadow-component/expected.html
@@ -1,4 +1,4 @@
-<x-test>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-shadow-component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-shadow-component/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-shadow-component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/light-template-shadow-component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-default-component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-default-component/expected.html
index 5cdcad4479..b19f0d19e5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-default-component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-default-component/expected.html
@@ -1,4 +1,4 @@
-<x-test>
+<fixture-test>
   <template shadowrootmode="open">
   </template>
-</x-test>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-default-component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-default-component/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-default-component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-default-component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-light-component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-light-component/expected.html
index 10501286b5..ccc2af9120 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-light-component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-light-component/expected.html
@@ -1,2 +1,2 @@
-<x-test>
-</x-test>
\ No newline at end of file
+<fixture-test>
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-light-component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-light-component/index.js
index bf9eb21437..bad417b8e3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-light-component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-mode-mismatch/shadow-template-light-component/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-test';
 export { default } from 'x/test';
-export * from 'x/test';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-with-unused-default-template/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/render-with-unused-default-template/expected.html
index 7d901f4cb7..1d6e4b66b2 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-with-unused-default-template/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-with-unused-default-template/expected.html
@@ -1,5 +1,5 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     Use me!!!
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/render-with-unused-default-template/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/render-with-unused-default-template/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/render-with-unused-default-template/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/render-with-unused-default-template/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/light/expected.html
index 1130c9b17d..556878c6fa 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     a
     <!---->
@@ -24,4 +24,4 @@
     <!---->
     d
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/shadow/expected.html
index 9b3f40fb6d..71f602fd2a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -36,4 +36,4 @@
       default6
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reordered-duplicate-nonexistent-slots/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reserved-keywords/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/reserved-keywords/expected.html
index 405936de6e..dcc9fe4fdb 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reserved-keywords/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reserved-keywords/expected.html
@@ -1,7 +1,7 @@
-<x-cmp>
+<fixture-test>
   <template shadowrootmode="open">
     <h1>
       hello
     </h1>
   </template>
-</x-cmp>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/reserved-keywords/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/reserved-keywords/index.js
index 55d4302e11..8a4b4a1ce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/reserved-keywords/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/reserved-keywords/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-cmp';
 export { default } from 'x/cmp';
-export * from 'x/cmp';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/advanced/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/advanced/expected.html
index 9b19697270..81dce454fd 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/advanced/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/advanced/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -49,4 +49,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/advanced/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/advanced/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/advanced/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/advanced/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/basic/expected.html
index 4233039c5b..ac82dadce7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/basic/expected.html
@@ -1,4 +1,4 @@
-<x-basic-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-basic-child>
       <div>
@@ -12,4 +12,4 @@
       </div>
     </x-basic-child>
   </template>
-</x-basic-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/basic/index.js
index 8ee445fea1..1d05726a56 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-basic-parent';
 export { default } from 'x/basicParent';
-export * from 'x/basicParent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names-attr-value/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names-attr-value/expected.html
index faeb7b5774..a3bed81824 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names-attr-value/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names-attr-value/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -31,4 +31,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names-attr-value/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names-attr-value/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names-attr-value/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names-attr-value/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names/expected.html
index 487d34bce0..54489f2d48 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -34,4 +34,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep-different-variable-names/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep/expected.html
index 9f5951b257..fe5c8fae00 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -34,4 +34,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/deep/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/default-slot/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/default-slot/expected.html
index 4377beae87..0fc5ef7632 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/default-slot/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/default-slot/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -12,4 +12,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/default-slot/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/default-slot/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/default-slot/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/default-slot/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/expression/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/expression/expected.html
index ba14e335aa..0ca1950f66 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/expression/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/expression/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -12,4 +12,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/expression/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/expression/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/expression/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/expression/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/for-each/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/for-each/expected.html
index 343baa3d9c..e752aebe07 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/for-each/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/for-each/expected.html
@@ -1,4 +1,4 @@
-<x-parent-of-child-with-for-each>
+<fixture-test>
   <template shadowrootmode="open">
     <style type="text/css">
       span {background-color: blue;}
@@ -26,4 +26,4 @@
       </ul>
     </x-child-with-for-each>
   </template>
-</x-parent-of-child-with-for-each>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/for-each/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/for-each/index.js
index 36c1edffa0..56baeec11b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/for-each/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/for-each/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent-of-child-with-for-each';
 export { default } from 'x/parentOfChildWithForEach';
-export * from 'x/parentOfChildWithForEach';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-2/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-2/expected.html
index bc5b3c817e..7d0313cb6a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-2/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-2/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -15,4 +15,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-2/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-2/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-2/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-2/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-3/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-3/expected.html
index 0ef40cedf9..904e679d14 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-3/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-3/expected.html
@@ -1,6 +1,6 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-3/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-3/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-3/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside-3/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside/expected.html
index 91fdf5fba8..5e70fbac24 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -15,4 +15,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-inside/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside-2/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside-2/expected.html
index 5e96bbcca5..f8f5abfb52 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside-2/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside-2/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -24,4 +24,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside-2/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside-2/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside-2/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside-2/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside/expected.html
index 0c03d18051..06c303c6f5 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -14,4 +14,4 @@
       </div>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/mixed-with-light-dom-slots-outside/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/named-slot/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/named-slot/expected.html
index a60adf648d..e5240b5b7c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/named-slot/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/named-slot/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <div>
@@ -17,4 +17,4 @@
       </p>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/named-slot/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/named-slot/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/named-slot/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/named-slot/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-var-name-in-child-and-scoped-slot/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-var-name-in-child-and-scoped-slot/expected.html
index 0055a1b155..da346b65f8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-var-name-in-child-and-scoped-slot/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-var-name-in-child-and-scoped-slot/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <aside>
@@ -27,4 +27,4 @@
       </aside>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-var-name-in-child-and-scoped-slot/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-var-name-in-child-and-scoped-slot/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-var-name-in-child-and-scoped-slot/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-var-name-in-child-and-scoped-slot/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-variable-used-outside/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-variable-used-outside/expected.html
index 184c61b587..b5d412d009 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-variable-used-outside/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-variable-used-outside/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <p>
       -1
@@ -26,4 +26,4 @@
       -1
     </p>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-variable-used-outside/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-variable-used-outside/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-variable-used-outside/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/same-variable-used-outside/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/undefined-var-name-in-child-and-scoped-slot/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/undefined-var-name-in-child-and-scoped-slot/expected.html
index f4d8732b68..a567adf934 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/undefined-var-name-in-child-and-scoped-slot/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/undefined-var-name-in-child-and-scoped-slot/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <x-child>
       <aside>
@@ -27,4 +27,4 @@
       </aside>
     </x-child>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/undefined-var-name-in-child-and-scoped-slot/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/undefined-var-name-in-child-and-scoped-slot/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/undefined-var-name-in-child-and-scoped-slot/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-slots/undefined-var-name-in-child-and-scoped-slot/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-styles-with-existing-class/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-styles-with-existing-class/expected.html
index a480a0fab2..a09682d84f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-styles-with-existing-class/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-styles-with-existing-class/expected.html
@@ -1,4 +1,4 @@
-<x-component class="lwc-6a8uqob2ku4-host" data-lwc-host-scope-token="lwc-6a8uqob2ku4-host">
+<fixture-test class="lwc-6a8uqob2ku4-host" data-lwc-host-scope-token="lwc-6a8uqob2ku4-host">
   <template shadowrootmode="open">
     <style class="lwc-6a8uqob2ku4" type="text/css">
       div.lwc-6a8uqob2ku4 {background-color: wheat;}
@@ -8,4 +8,4 @@
     <div class="bar lwc-6a8uqob2ku4">
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-styles-with-existing-class/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-styles-with-existing-class/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-styles-with-existing-class/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/scoped-styles-with-existing-class/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/shadow-dom-styles-dir-host/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/shadow-dom-styles-dir-host/expected.html
index 6147ab8798..bf12db9074 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/shadow-dom-styles-dir-host/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/shadow-dom-styles-dir-host/expected.html
@@ -1,4 +1,4 @@
-<x-basic class="lwc-1rssj1tib70-host" data-lwc-host-scope-token="lwc-1rssj1tib70-host">
+<fixture-test class="lwc-1rssj1tib70-host" data-lwc-host-scope-token="lwc-1rssj1tib70-host">
   <template shadowrootmode="open">
     <style class="lwc-1rssj1tib70" type="text/css">
        :dir(rtl) {margin-left: 0;}:host {color: red;}
@@ -10,4 +10,4 @@
       Hello
     </p>
   </template>
-</x-basic>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/shadow-dom-styles-dir-host/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/shadow-dom-styles-dir-host/index.js
index 12a4de763d..2dac65f07e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/shadow-dom-styles-dir-host/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/shadow-dom-styles-dir-host/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-basic';
 export { default } from 'x/basic';
-export * from 'x/basic';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/scoped-slots/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/scoped-slots/expected.html
index 1ce037982f..1a9b90734e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/scoped-slots/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/scoped-slots/expected.html
@@ -1,4 +1,4 @@
-<x-light-container>
+<fixture-test>
   <x-scoped-slot-parent>
     <x-scoped-slot-child>
       <x-leaf>
@@ -14,4 +14,4 @@ <h2>
       </x-leaf>
     </x-scoped-slot-child>
   </x-scoped-slot-parent>
-</x-light-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/scoped-slots/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/scoped-slots/index.js
index ee7369077e..413a2a15dc 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/scoped-slots/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/scoped-slots/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-light-container';
 export { default } from 'x/lightContainer';
-export * from 'x/lightContainer';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling-component/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling-component/expected.html
index 63ea1759fe..b02c2f38b6 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling-component/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling-component/expected.html
@@ -1,4 +1,4 @@
-<x-dangling-container>
+<fixture-test>
   <x-slot>
     <x-leaf>
       <!---->
@@ -13,4 +13,4 @@
       <!---->
     </x-leaf>
   </x-slot>
-</x-dangling-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling-component/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling-component/index.js
index b202a15a0a..420d88855d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling-component/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling-component/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-dangling-container';
 export { default } from 'x/container';
-export * from 'x/container';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling/expected.html
index adfb2329a5..8ebe936914 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling/expected.html
@@ -1,4 +1,4 @@
-<x-dangling-container>
+<fixture-test>
   <x-slot>
     <x-leaf>
       <!---->
@@ -13,4 +13,4 @@ <h2>
       <!---->
     </x-leaf>
   </x-slot>
-</x-dangling-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling/index.js
index b202a15a0a..420d88855d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/dangling/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-dangling-container';
 export { default } from 'x/container';
-export * from 'x/container';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/light/expected.html
index 775c4c9602..2dfd1f0cc1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/light/expected.html
@@ -1,4 +1,4 @@
-<x-light-container>
+<fixture-test>
   <x-slot>
     <x-leaf>
       <!---->
@@ -13,4 +13,4 @@ <h1>
       <!---->
     </x-leaf>
   </x-slot>
-</x-light-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/light/index.js
index 2230255735..420d88855d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/light/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-light-container';
 export { default } from 'x/container';
-export * from 'x/container';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/mixed/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/mixed/expected.html
index 320de2c749..b4be730c61 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/mixed/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/mixed/expected.html
@@ -1,4 +1,4 @@
-<x-mixed-container>
+<fixture-test>
   <template shadowrootmode="open">
     <x-light-parent>
       <x-shadow-leaf>
@@ -37,4 +37,4 @@
       </div>
     </x-shadow-parent>
   </template>
-</x-mixed-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/mixed/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/mixed/index.js
index 278804639e..420d88855d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/mixed/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/mixed/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-mixed-container';
 export { default } from 'x/container';
-export * from 'x/container';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/shadow/expected.html
index c1af072344..73a782dc99 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-shadow-container>
+<fixture-test>
   <template shadowrootmode="open">
     <x-slot>
       <template shadowrootmode="open">
@@ -23,4 +23,4 @@ <h1 slot="bottom">
       </h1>
     </x-slot>
   </template>
-</x-shadow-container>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/shadow/index.js
index 8c80133fc7..420d88855d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-forwarding/slots/shadow/index.js
@@ -1,4 +1 @@
-export const tagName = 'x-shadow-container';
 export { default } from 'x/container';
-export * from 'x/container';
-export const features = [];
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/light/expected.html
index 76c9148546..e3d6543ac8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     !
     <!---->
@@ -69,4 +69,4 @@
     <!---->
     $
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/shadow/expected.html
index 72602880e8..26802867d7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -88,4 +88,4 @@
       8
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/ifTrue/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/light/expected.html
index c7c802d0b0..1198f0a7cd 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     !
     <!---->
@@ -73,4 +73,4 @@
     <!---->
     $
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/shadow/expected.html
index eeca2ac5ec..4ab7613786 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -92,4 +92,4 @@
       8
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/advanced/lwcIf/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/light/expected.html
index f719e7fd75..a64d0cdc78 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     a
     <!---->
@@ -19,4 +19,4 @@
     <!---->
     c
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/shadow/expected.html
index 84480b9c44..9ee358545c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -24,4 +24,4 @@
       </div>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/element/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/light/expected.html
index ef83eb1476..8db41c489a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     a
     <!---->
@@ -19,4 +19,4 @@
     <!---->
     c
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/shadow/expected.html
index 60c6b2c781..a371814c5f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -24,4 +24,4 @@
       </x-external>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/external/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/light/expected.html
index 24d9d79a41..7e35c6804b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     a
     <!---->
@@ -15,4 +15,4 @@
     <!---->
     c
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/shadow/expected.html
index dda18b9423..a8bc259a40 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -20,4 +20,4 @@
       </div>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/ifTrue/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/light/expected.html
index ff21d3ea66..43d629f13e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/light/expected.html
@@ -1,7 +1,7 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     <!---->
     123
     <!---->
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/shadow/expected.html
index b73385dd06..8b55e1a5b8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -8,4 +8,4 @@
       123
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slot/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/light/expected.html
index ed7cbfce7c..ea833339ec 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     <!---->
     <div>
@@ -10,4 +10,4 @@
     </div>
     <!---->
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/shadow/expected.html
index f021775307..8824a78087 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -14,4 +14,4 @@
       </div>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf-inside-slotted-element/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/light/expected.html
index 24d9d79a41..7e35c6804b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     a
     <!---->
@@ -15,4 +15,4 @@
     <!---->
     c
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/shadow/expected.html
index dda18b9423..a8bc259a40 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -20,4 +20,4 @@
       </div>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/lwcIf/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/light/expected.html
index 2acdfd8250..ff1e4d8e3f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/light/expected.html
@@ -1,7 +1,7 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     <!---->
     fallback for foo
     <!---->
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/shadow/expected.html
index cbcb19bdfa..19f4edb511 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -21,4 +21,4 @@
       8
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/ifTrue/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/light/expected.html
index 2acdfd8250..ff1e4d8e3f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/light/expected.html
@@ -1,7 +1,7 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     <!---->
     fallback for foo
     <!---->
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/shadow/expected.html
index f9472c6fb3..4091a0e577 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -25,4 +25,4 @@
       8
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/nested-elements/lwcIf/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/light/expected.html
index 87e50dcca7..2d3451bb11 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     <div>
       Inner!
@@ -15,4 +15,4 @@
     ‍‍
     <!---->
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/shadow/expected.html
index 87c4cd0b6c..b7972d9ba4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -21,4 +21,4 @@
       ‍‍
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if-as-sibling/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/light/expected.html
index 1a64f58200..bd7fbb8a97 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <div>
     Outer!
   </div>
@@ -23,4 +23,4 @@
     ‍‍
     <!---->
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/shadow/expected.html
index 7c926a3133..0d8d19cd81 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Outer!
@@ -29,4 +29,4 @@
       ‍‍
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/if/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/light/expected.html
index 87e50dcca7..2d3451bb11 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     <div>
       Inner!
@@ -15,4 +15,4 @@
     ‍‍
     <!---->
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/shadow/expected.html
index 87c4cd0b6c..b7972d9ba4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -21,4 +21,4 @@
       ‍‍
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf-as-sibling/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/light/expected.html
index a2b2521187..c3f29b6985 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <div>
     Outer!
   </div>
@@ -25,4 +25,4 @@
     <!---->
   </x-inner>
   <!---->
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/shadow/expected.html
index 3b8130e249..d185ffa716 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Outer!
@@ -31,4 +31,4 @@
     </x-inner>
     <!---->
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slot-not-at-top-level/with-adjacent-text-nodes/lwcIf/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slotchange/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slotchange/expected.html
index 2207d1616d..b1fd6f513a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slotchange/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slotchange/expected.html
@@ -1,4 +1,4 @@
-<x-slotchange>
+<fixture-test>
   <template shadowrootmode="open">
     <x-receiver>
       <template shadowrootmode="open">
@@ -11,4 +11,4 @@
       </div>
     </x-receiver>
   </template>
-</x-slotchange>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slotchange/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slotchange/index.js
index 65ea1f4bfe..72b3402902 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slotchange/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slotchange/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-slotchange';
 export { default } from 'x/slotchange';
-export * from 'x/slotchange';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/light/expected.html
index cab2f97a97..c73717e6d9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     a
     <!---->
@@ -10,4 +10,4 @@
     <!---->
     c
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/shadow/expected.html
index 569fbf11fd..d8a02d2ecf 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -14,4 +14,4 @@
       </template>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/fallback/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/light/expected.html
index ada6887b85..43ae95bb9a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/shadow/expected.html
index bc3c9ecc25..f989e85f15 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -9,4 +9,4 @@
       </div>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/implicit-no-template/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/light/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/light/expected.html
index f45b9a6e77..2a003e399d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/light/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/light/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <x-inner>
     a
     <!---->
@@ -12,4 +12,4 @@
     <!---->
     c
   </x-inner>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/light/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/light/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/light/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/light/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/shadow/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/shadow/expected.html
index 4c95c428f8..7c36666b96 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/shadow/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/shadow/expected.html
@@ -1,4 +1,4 @@
-<x-outer>
+<fixture-test>
   <template shadowrootmode="open">
     <x-inner>
       <template shadowrootmode="open">
@@ -18,4 +18,4 @@
       </div>
     </x-inner>
   </template>
-</x-outer>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/shadow/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/shadow/index.js
index 17a015b5ea..c8a6d12734 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/shadow/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-basic/slotted/shadow/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-outer';
 export { default } from 'x/outer';
-export * from 'x/outer';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-fallback/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-fallback/expected.html
index b580e98b7d..ee2c9f9235 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-fallback/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-fallback/expected.html
@@ -1,4 +1,4 @@
-<x-slots-fallback>
+<fixture-test>
   <template shadowrootmode="open">
     <x-receiver>
       <template shadowrootmode="open">
@@ -19,4 +19,4 @@
       </div>
     </x-receiver>
   </template>
-</x-slots-fallback>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-fallback/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-fallback/index.js
index 84b952463e..6c40a3e062 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-fallback/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-fallback/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-slots-fallback';
 export { default } from 'x/slots-fallback';
-export * from 'x/slots-fallback';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-nested/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-nested/expected.html
index 733b574752..f813387e0a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-nested/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-nested/expected.html
@@ -1,4 +1,4 @@
-<x-slots-nested>
+<fixture-test>
   <template shadowrootmode="open">
     <x-parent>
       <template shadowrootmode="open">
@@ -16,4 +16,4 @@
       </div>
     </x-parent>
   </template>
-</x-slots-nested>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-nested/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-nested/index.js
index fe935d1225..d672d22d94 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-nested/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-nested/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-slots-nested';
 export { default } from 'x/slots-nested';
-export * from 'x/slots-nested';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-unknown/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-unknown/expected.html
index 9429525b50..2b4e349cac 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-unknown/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-unknown/expected.html
@@ -1,4 +1,4 @@
-<x-slots-unknown>
+<fixture-test>
   <template shadowrootmode="open">
     <x-receiver>
       <template shadowrootmode="open">
@@ -13,4 +13,4 @@
       </div>
     </x-receiver>
   </template>
-</x-slots-unknown>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-unknown/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-unknown/index.js
index 7dcc710af4..0946bf9495 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots-unknown/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots-unknown/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-slots-unknown';
 export { default } from 'x/slots-unknown';
-export * from 'x/slots-unknown';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slots/expected.html
index 5ee62d5630..e65d512c76 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots/expected.html
@@ -1,4 +1,4 @@
-<x-slots>
+<fixture-test>
   <template shadowrootmode="open">
     <x-receiver>
       <template shadowrootmode="open">
@@ -28,4 +28,4 @@
       G
     </x-receiver>
   </template>
-</x-slots>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slots/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slots/index.js
index ef585717fe..bcedbda48e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slots/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slots/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-slots';
 export { default } from 'x/slots';
-export * from 'x/slots';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slotted-content-nested/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/slotted-content-nested/expected.html
index 55df76a192..0c65121411 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slotted-content-nested/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slotted-content-nested/expected.html
@@ -1,4 +1,4 @@
-<x-slots>
+<fixture-test>
   <template shadowrootmode="open">
     <x-receiver>
       <template shadowrootmode="open">
@@ -19,4 +19,4 @@
       </div>
     </x-receiver>
   </template>
-</x-slots>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/slotted-content-nested/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/slotted-content-nested/index.js
index ef585717fe..bcedbda48e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/slotted-content-nested/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/slotted-content-nested/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-slots';
 export { default } from 'x/slots';
-export * from 'x/slots';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/ssr-internals/expected-ssr.html b/packages/@lwc/engine-server/src/__tests__/fixtures/ssr-internals/expected-ssr.html
index 1008a98dec..3bbce02bf3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/ssr-internals/expected-ssr.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/ssr-internals/expected-ssr.html
@@ -1,4 +1,4 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <p>
       this only matters for ssr-compiler; engine-server does not have the same internals
@@ -13,4 +13,4 @@
       public props overridden: false
     </p>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/ssr-internals/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/ssr-internals/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/ssr-internals/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/ssr-internals/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-dynamic-render/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-dynamic-render/expected.html
index eab23b9e8c..164e84f4a0 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-dynamic-render/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-dynamic-render/expected.html
@@ -1,4 +1,4 @@
-<x-stylish class="lwc-72njdrv8nr1-host" data-lwc-host-scope-token="lwc-72njdrv8nr1-host">
+<fixture-test class="lwc-72njdrv8nr1-host" data-lwc-host-scope-token="lwc-72njdrv8nr1-host">
   <template shadowrootmode="open">
     <style class="lwc-72njdrv8nr1" type="text/css">
       h1 {border: 1px solid goldenrod;}
@@ -16,4 +16,4 @@ <h1 class="lwc-72njdrv8nr1">
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-dynamic-render/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-dynamic-render/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-dynamic-render/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-dynamic-render/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-class/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-class/expected.html
index d02f743429..4ad8d36df3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-class/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-class/expected.html
@@ -1,4 +1,4 @@
-<x-stylish class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
+<fixture-test class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
   <template shadowrootmode="open">
     <style class="lwc-1l667kdb4s5" type="text/css">
       .yolo {background: royalblue;}
@@ -10,4 +10,4 @@ <h1 class="lwc-1l667kdb4s5 yolo">
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-class/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-class/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-class/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-class/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-dynamic-class/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-dynamic-class/expected.html
index d02f743429..4ad8d36df3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-dynamic-class/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-dynamic-class/expected.html
@@ -1,4 +1,4 @@
-<x-stylish class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
+<fixture-test class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
   <template shadowrootmode="open">
     <style class="lwc-1l667kdb4s5" type="text/css">
       .yolo {background: royalblue;}
@@ -10,4 +10,4 @@ <h1 class="lwc-1l667kdb4s5 yolo">
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-dynamic-class/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-dynamic-class/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-dynamic-class/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped-with-dynamic-class/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped/expected.html
index 4d6271bef8..e68b46a0f7 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped/expected.html
@@ -1,4 +1,4 @@
-<x-stylish class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
+<fixture-test class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
   <template shadowrootmode="open">
     <style class="lwc-1l667kdb4s5" type="text/css">
       h1 {background: royalblue;}
@@ -10,4 +10,4 @@ <h1 class="lwc-1l667kdb4s5">
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/scoped-and-unscoped/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-class/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-class/expected.html
index 2c5d117ad4..26ca09e765 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-class/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-class/expected.html
@@ -1,4 +1,4 @@
-<x-stylish>
+<fixture-test>
   <template shadowrootmode="open">
     <style type="text/css">
       .yolo {background: royalblue;}
@@ -7,4 +7,4 @@ <h1 class="yolo">
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-class/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-class/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-class/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-class/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-dynamic-class/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-dynamic-class/expected.html
index 2c5d117ad4..26ca09e765 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-dynamic-class/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-dynamic-class/expected.html
@@ -1,4 +1,4 @@
-<x-stylish>
+<fixture-test>
   <template shadowrootmode="open">
     <style type="text/css">
       .yolo {background: royalblue;}
@@ -7,4 +7,4 @@ <h1 class="yolo">
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-dynamic-class/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-dynamic-class/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-dynamic-class/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only-with-dynamic-class/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only/expected.html
index cc7f1c52e1..33df11f71e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only/expected.html
@@ -1,4 +1,4 @@
-<x-stylish>
+<fixture-test>
   <template shadowrootmode="open">
     <style type="text/css">
       h1 {background: royalblue;}
@@ -7,4 +7,4 @@ <h1>
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-only/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles-and-class/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles-and-class/expected.html
index c54dcc2222..36ed374708 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles-and-class/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles-and-class/expected.html
@@ -1,4 +1,4 @@
-<x-stylish class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
+<fixture-test class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
   <template shadowrootmode="open">
     <style class="lwc-1l667kdb4s5" type="text/css">
       h1.lwc-1l667kdb4s5 {opacity: 0.5;}
@@ -10,4 +10,4 @@ <h1 class="lwc-1l667kdb4s5 yolo">
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles-and-class/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles-and-class/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles-and-class/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles-and-class/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles/expected.html
index dd77e070bb..37b998ea63 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles/expected.html
@@ -1,4 +1,4 @@
-<x-stylish class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
+<fixture-test class="lwc-1l667kdb4s5-host" data-lwc-host-scope-token="lwc-1l667kdb4s5-host">
   <template shadowrootmode="open">
     <style class="lwc-1l667kdb4s5" type="text/css">
       h1.lwc-1l667kdb4s5 {opacity: 0.5;}
@@ -10,4 +10,4 @@ <h1 class="lwc-1l667kdb4s5">
       hello
     </h1>
   </template>
-</x-stylish>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles/index.js
index e731a3c77c..2f5ca4ed74 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/static-stylesheets/unscoped-with-scoped-template-styles/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-stylish';
 export { default } from 'x/stylish';
-export * from 'x/stylish';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/style-class-whitespace/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/style-class-whitespace/expected.html
index 26ecbc7e98..049c3e365e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/style-class-whitespace/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/style-class-whitespace/expected.html
@@ -1,4 +1,4 @@
-<x-foo>
+<fixture-test>
   <template shadowrootmode="open">
     <div style="color: red !important;">
     </div>
@@ -55,4 +55,4 @@
     <div class="bar foo">
     </div>
   </template>
-</x-foo>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/style-class-whitespace/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/style-class-whitespace/index.js
index f9fc715d9f..4bc63acf20 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/style-class-whitespace/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/style-class-whitespace/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-foo';
 export { default } from 'x/foo';
-export * from 'x/foo';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/style-newline/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/style-newline/expected.html
index 0020c51a8c..be3b1596ba 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/style-newline/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/style-newline/expected.html
@@ -1,8 +1,8 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div style="color: yellow;">
     </div>
     <span style="color: purple; background-color: orange;">
     </span>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/style-newline/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/style-newline/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/style-newline/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/style-newline/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-multiple-levels/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-multiple-levels/index.js
index 2d0f6dfe87..28055c0dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-multiple-levels/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-multiple-levels/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-styles';
 export { default } from 'x/styles';
-export * from 'x/styles';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-trailing-close-tag/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-trailing-close-tag/index.js
index 2d0f6dfe87..28055c0dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-trailing-close-tag/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-trailing-close-tag/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-styles';
 export { default } from 'x/styles';
-export * from 'x/styles';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-trailing-open-tag/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-trailing-open-tag/index.js
index 2d0f6dfe87..28055c0dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-trailing-open-tag/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-trailing-open-tag/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-styles';
 export { default } from 'x/styles';
-export * from 'x/styles';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-unclosed-open-tag/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-unclosed-open-tag/index.js
index 2d0f6dfe87..28055c0dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-unclosed-open-tag/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-invalid-unclosed-open-tag/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-styles';
 export { default } from 'x/styles';
-export * from 'x/styles';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-safe/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-safe/expected.html
index f16594b959..24d68efd27 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-safe/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-safe/expected.html
@@ -1,7 +1,7 @@
-<x-styles>
+<fixture-test>
   <template shadowrootmode="open">
     <style type="text/css">
       [data-foo="'&<>"] {color: black;}[data-foo='"'] {color: white;}
     </style>
   </template>
-</x-styles>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-safe/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-safe/index.js
index 2d0f6dfe87..28055c0dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-safe/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-safe/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-styles';
 export { default } from 'x/styles';
-export * from 'x/styles';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-unsafe/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-unsafe/index.js
index 2d0f6dfe87..28055c0dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-unsafe/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-escaping-unsafe/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-styles';
 export { default } from 'x/styles';
-export * from 'x/styles';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-keyframes/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-keyframes/expected.html
index 0a741b097b..cf1b408342 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-keyframes/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-keyframes/expected.html
@@ -1,4 +1,4 @@
-<x-styles>
+<fixture-test>
   <template shadowrootmode="open">
     <style type="text/css">
       @keyframes spin {0% {transform: rotate(0deg);}100% {transform: rotate(360deg);}}.spin {animation: 1s linear infinite spin;}
@@ -6,4 +6,4 @@
     <div class="spin">
     </div>
   </template>
-</x-styles>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-keyframes/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-keyframes/index.js
index 2d0f6dfe87..28055c0dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-keyframes/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-keyframes/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-styles';
 export { default } from 'x/styles';
-export * from 'x/styles';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-shared/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-shared/expected.html
index a5bd1313b1..c7fe2b4be6 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-shared/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-shared/expected.html
@@ -1,4 +1,4 @@
-<x-parent>
+<fixture-test>
   <template shadowrootmode="open">
     <style type="text/css">
       div {border: 1px solid turquoise;}
@@ -23,4 +23,4 @@
       Hello parent
     </div>
   </template>
-</x-parent>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-shared/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-shared/index.js
index d5a55ceefa..f717b3a35a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles-shared/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles-shared/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-parent';
 export { default } from 'x/parent';
-export * from 'x/parent';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/styles/expected.html
index c68eeb5e3d..146ccd051a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles/expected.html
@@ -1,4 +1,4 @@
-<x-styles>
+<fixture-test>
   <template shadowrootmode="open">
     <style type="text/css">
       :host {color: red;}.foo {color: blue;}.foo .bar {color: green;}
@@ -8,4 +8,4 @@
       </p>
     </div>
   </template>
-</x-styles>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/styles/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/styles/index.js
index 2d0f6dfe87..28055c0dd8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/styles/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/styles/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-styles';
 export { default } from 'x/styles';
-export * from 'x/styles';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/fancy/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/fancy/expected.html
index b933ae595d..bc594c18cd 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/fancy/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/fancy/expected.html
@@ -1,7 +1,7 @@
-<x-component data-lwc-host-mutated="data-yolo" data-yolo>
+<fixture-test data-lwc-host-mutated="data-yolo" data-yolo>
   <template shadowrootmode="open">
     <div>
       base mixin hello
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/fancy/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/fancy/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/fancy/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/fancy/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/mixin/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/mixin/expected.html
index 6cad51894b..0e3421ca0a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/mixin/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/mixin/expected.html
@@ -1,4 +1,4 @@
-<x-component data-lwc-host-mutated="data-yolo" data-yolo>
+<fixture-test data-lwc-host-mutated="data-yolo" data-yolo>
   <template shadowrootmode="open">
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/mixin/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/mixin/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/mixin/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/mixin/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/no-template-in-superclass/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/no-template-in-superclass/expected.html
index 3d20afa5f1..85e45e204d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/no-template-in-superclass/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/no-template-in-superclass/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       hello world
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/no-template-in-superclass/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/no-template-in-superclass/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/no-template-in-superclass/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/no-template-in-superclass/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/not-superclass/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/not-superclass/expected.html
index dfd20141b8..424e212f10 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/not-superclass/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/not-superclass/expected.html
@@ -1,5 +1,5 @@
-<x-component data-lwc-host-mutated="data-yolo" data-yolo>
+<fixture-test data-lwc-host-mutated="data-yolo" data-yolo>
   <template shadowrootmode="open">
     yay ook ook ook
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/not-superclass/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/not-superclass/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/not-superclass/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/not-superclass/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/override/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/override/expected.html
index 3d20afa5f1..85e45e204d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/override/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/override/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       hello world
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/override/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/override/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/override/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/override/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/no-template-in-subclass/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/no-template-in-subclass/expected.html
index c9d7568cf8..4625596236 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/no-template-in-subclass/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/no-template-in-subclass/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       foobar
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/no-template-in-subclass/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/no-template-in-subclass/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/no-template-in-subclass/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/no-template-in-subclass/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/render-in-subclass/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/render-in-subclass/expected.html
index 3ca4b516a7..05596028f8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/render-in-subclass/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/render-in-subclass/expected.html
@@ -1,5 +1,5 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     From subclass! foobar
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/render-in-subclass/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/render-in-subclass/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/render-in-subclass/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/render-in-subclass/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/template-in-subclass/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/template-in-subclass/expected.html
index c9d7568cf8..4625596236 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/template-in-subclass/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/template-in-subclass/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       foobar
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/template-in-subclass/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/template-in-subclass/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/template-in-subclass/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/template-in-subclass/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-subclass/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-subclass/expected.html
index 82f0e42608..1aa5844c48 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-subclass/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-subclass/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       yolo
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-subclass/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-subclass/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-subclass/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-subclass/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-superclass/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-superclass/expected.html
index c9d7568cf8..4625596236 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-superclass/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-superclass/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       foobar
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-superclass/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-superclass/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-superclass/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/render-in-superclass/unused-default-in-superclass/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/basic/expected.html
index 9061812395..6b6256368b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/basic/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       hello
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/basic/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/render-in-subclass/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/render-in-subclass/expected.html
index 6334f2b8af..412ec4d6de 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/render-in-subclass/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/render-in-subclass/expected.html
@@ -1,7 +1,7 @@
-<x-sub>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Hello from the subclass, world!
     </div>
   </template>
-</x-sub>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/render-in-subclass/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/render-in-subclass/index.js
index 5ab115aa5b..13c7fbfc99 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/render-in-subclass/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/render-in-subclass/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-sub';
 export { default } from 'x/sub';
-export * from 'x/sub';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-render-in-super-super/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-render-in-super-super/expected.html
index 10d4747c0e..ef7705d297 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-render-in-super-super/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-render-in-super-super/expected.html
@@ -1,7 +1,7 @@
-<x-sub>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Hello from the super-super class, world!
     </div>
   </template>
-</x-sub>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-render-in-super-super/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-render-in-super-super/index.js
index 5ab115aa5b..13c7fbfc99 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-render-in-super-super/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-render-in-super-super/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-sub';
 export { default } from 'x/sub';
-export * from 'x/sub';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super-render-in-super/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super-render-in-super/expected.html
index c434240160..7551dfeb8f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super-render-in-super/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super-render-in-super/expected.html
@@ -1,7 +1,7 @@
-<x-sub>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Hello from the super class, world!
     </div>
   </template>
-</x-sub>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super-render-in-super/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super-render-in-super/index.js
index 5ab115aa5b..13c7fbfc99 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super-render-in-super/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super-render-in-super/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-sub';
 export { default } from 'x/sub';
-export * from 'x/sub';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super/expected.html
index eb7ff134a0..70ad316157 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super/expected.html
@@ -1,7 +1,7 @@
-<x-sub>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Hello world
     </div>
   </template>
-</x-sub>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super/index.js
index 5ab115aa5b..13c7fbfc99 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/template-in-superclass/template-in-super-super/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-sub';
 export { default } from 'x/sub';
-export * from 'x/sub';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/with-props/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/with-props/expected.html
index f906190c7f..436ccbd24d 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/with-props/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/with-props/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Hello hahaha yolo
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/with-props/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/with-props/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/with-props/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/superclass/with-props/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/svgs/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/svgs/expected.html
index 452511dc85..25bd171394 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/svgs/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/svgs/expected.html
@@ -1,4 +1,4 @@
-<x-svgs>
+<fixture-test>
   <template shadowrootmode="open">
     <svg height="150" width="400">
       <defs>
@@ -23,4 +23,4 @@
       <path/>
     </svg>
   </template>
-</x-svgs>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/svgs/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/svgs/index.js
index a4de3b811e..720c0fccf4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/svgs/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/svgs/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-svgs';
 export { default } from 'x/svgs';
-export * from 'x/svgs';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/tag-name/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/tag-name/expected.html
index 7cbeea8a66..6d3719911b 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/tag-name/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/tag-name/expected.html
@@ -1,7 +1,7 @@
-<x-tag-name>
+<fixture-test>
   <template shadowrootmode="open">
     <span>
-      X-TAG-NAME
+      FIXTURE-TEST
     </span>
   </template>
-</x-tag-name>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/tag-name/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/tag-name/index.js
index 3921947682..06d7749701 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/tag-name/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/tag-name/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-tag-name';
 export { default } from 'x/tag-name';
-export * from 'x/tag-name';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation-escape/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation-escape/expected.html
index d171915458..e9a8b0313e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation-escape/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation-escape/expected.html
@@ -1,5 +1,5 @@
-<x-text-interpolation-escape>
+<fixture-test>
   <template shadowrootmode="open">
     I &lt;b&gt;should&lt;/b&gt; escape &#x27;this&#x27; &amp; &quot;that&quot;
   </template>
-</x-text-interpolation-escape>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation-escape/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation-escape/index.js
index 637dfed584..efca9069d2 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation-escape/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation-escape/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-text-interpolation-escape';
 export { default } from 'x/text-interpolation-escape';
-export * from 'x/text-interpolation-escape';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation/expected.html
index 9b81597a42..b5a789aeb8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation/expected.html
@@ -1,4 +1,4 @@
-<x-text-interpolation>
+<fixture-test>
   <template shadowrootmode="open">
     <p>
       Public property: public-prop
@@ -7,4 +7,4 @@
       Private property: private-prop
     </p>
   </template>
-</x-text-interpolation>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation/index.js
index 16390c9264..233bb0111f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/text-interpolation/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-text-interpolation';
 export { default } from 'x/text-interpolation';
-export * from 'x/text-interpolation';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/text-static/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/text-static/expected.html
index 37c7dc5cb6..db08c4469c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/text-static/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/text-static/expected.html
@@ -1,5 +1,5 @@
-<x-text-static>
+<fixture-test>
   <template shadowrootmode="open">
     Static text
   </template>
-</x-text-static>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/text-static/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/text-static/index.js
index 2034aa1e61..dddccbd998 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/text-static/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/text-static/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-text-static';
 export { default } from 'x/text-static';
-export * from 'x/text-static';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/this-dot-host-element/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/this-dot-host-element/index.js
index 2f505148a7..09032c2b4c 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/this-dot-host-element/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/this-dot-host-element/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-this-dot-host-element';
 export { default } from 'x/this-dot-host-element';
-export * from 'x/this-dot-host-element';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/track-revoked-proxy-fails/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/track-revoked-proxy-fails/expected.html
index 6538e926a9..fb2a1f447e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/track-revoked-proxy-fails/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/track-revoked-proxy-fails/expected.html
@@ -1,5 +1,5 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     I should render!
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/track-revoked-proxy-fails/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/track-revoked-proxy-fails/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/track-revoked-proxy-fails/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/track-revoked-proxy-fails/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/very-deeply-nested-each/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/very-deeply-nested-each/expected.html
index 0f1a1b5d5b..e056afaf10 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/very-deeply-nested-each/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/very-deeply-nested-each/expected.html
@@ -1,7 +1,7 @@
-<x-component>
+<fixture-test>
   <template shadowrootmode="open">
     <div data-value="yolo">
       yolo
     </div>
   </template>
-</x-component>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/very-deeply-nested-each/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/very-deeply-nested-each/index.js
index cd34090d2c..ff988e5ee9 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/very-deeply-nested-each/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/very-deeply-nested-each/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-component';
 export { default } from 'x/component';
-export * from 'x/component';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/basic/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/basic/expected.html
index b3477dc689..e79b724657 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/basic/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/basic/expected.html
@@ -1,5 +1,5 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     Wire adapter invoked: true
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/basic/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/basic/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/basic/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/basic/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/get-set/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/get-set/expected.html
index 430f214a18..4eb992a43f 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/get-set/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/get-set/expected.html
@@ -1,7 +1,7 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     <div>
       Wired? set
     </div>
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/get-set/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/get-set/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/get-set/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/get-set/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/method-prop/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/method-prop/expected.html
index ca77f1f1f5..72ab150cb3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/method-prop/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/method-prop/expected.html
@@ -1,5 +1,5 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     propAndMethod
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/method-prop/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/method-prop/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/method-prop/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/method-prop/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/prop-method/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/prop-method/expected.html
index ca77f1f1f5..72ab150cb3 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/prop-method/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/prop-method/expected.html
@@ -1,5 +1,5 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     propAndMethod
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/prop-method/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/prop-method/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/prop-method/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/collision/prop-method/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/config/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/config/expected.html
index 73debe9ade..1f6bcba4b8 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/config/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/config/expected.html
@@ -1,4 +1,4 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     Wire adapter value: {
     : ,
@@ -17,4 +17,4 @@
     why: undefined,
 }
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/config/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/config/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/config/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/config/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/deep-reference/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/deep-reference/expected.html
index ee0e2cba98..cbb89f6a2e 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/deep-reference/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/deep-reference/expected.html
@@ -1,7 +1,7 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     Wire adapter value: {
     deep: yolo
 }
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/deep-reference/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/deep-reference/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/deep-reference/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/deep-reference/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/computed-prop-updates-incorrectly/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/computed-prop-updates-incorrectly/expected.html
index 1c8de4df88..6e6fde6656 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/computed-prop-updates-incorrectly/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/computed-prop-updates-incorrectly/expected.html
@@ -1,4 +1,4 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     <p>
       Prop named symbol that should not be used: wire data
@@ -7,4 +7,4 @@
       Prop with symbol key that should be used: unset
     </p>
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/computed-prop-updates-incorrectly/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/computed-prop-updates-incorrectly/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/computed-prop-updates-incorrectly/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/computed-prop-updates-incorrectly/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-getter/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-getter/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-getter/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-getter/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-method/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-method/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-method/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-method/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-setter/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-setter/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-setter/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-on-computed-setter/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-colliding-prop-then-method/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-colliding-prop-then-method/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-colliding-prop-then-method/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-colliding-prop-then-method/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-expression/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-expression/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-expression/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-expression/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-let-variable/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-let-variable/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-let-variable/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-let-variable/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-regexp-literal/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-regexp-literal/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-regexp-literal/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-regexp-literal/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-template-literal/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-template-literal/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-template-literal/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-computed-prop-is-template-literal/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-using-2-wired-decorators/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-using-2-wired-decorators/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-using-2-wired-decorators/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-using-2-wired-decorators/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-method-is-combined-with-@api/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-method-is-combined-with-@api/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-method-is-combined-with-@api/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-method-is-combined-with-@api/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-property-is-combined-with-@api/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-property-is-combined-with-@api/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-property-is-combined-with-@api/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-property-is-combined-with-@api/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-property-is-combined-with-@track/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-property-is-combined-with-@track/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-property-is-combined-with-@track/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/errors/throws-when-wired-property-is-combined-with-@track/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/field/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/field/expected.html
index d753c1fdb7..0e83a81401 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/field/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/field/expected.html
@@ -1,8 +1,8 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     wired field value: {
     key1: foo,
     key2: [fixed,array],
 }
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/field/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/field/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/field/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/field/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/get-set/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/get-set/expected.html
index ed0cb1dd75..65e3a34b2a 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/get-set/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/get-set/expected.html
@@ -1,5 +1,5 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     getterOnly setterOnly getterWithSetter setterWithGetter bothDecorated
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/get-set/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/get-set/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/get-set/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/get-set/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/imported-member/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/imported-member/expected.html
index 76e91d6766..e1d0c458b1 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/imported-member/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/imported-member/expected.html
@@ -1,7 +1,7 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     Wire adapter value: {
     value: yolo
 }
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/imported-member/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/imported-member/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/imported-member/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/imported-member/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/method/expected.html b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/method/expected.html
index d753c1fdb7..0e83a81401 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/method/expected.html
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/method/expected.html
@@ -1,8 +1,8 @@
-<x-wire>
+<fixture-test>
   <template shadowrootmode="open">
     wired field value: {
     key1: foo,
     key2: [fixed,array],
 }
   </template>
-</x-wire>
\ No newline at end of file
+</fixture-test>
\ No newline at end of file
diff --git a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/method/index.js b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/method/index.js
index fafb890973..12b9eb94e4 100644
--- a/packages/@lwc/engine-server/src/__tests__/fixtures/wire/method/index.js
+++ b/packages/@lwc/engine-server/src/__tests__/fixtures/wire/method/index.js
@@ -1,3 +1 @@
-export const tagName = 'x-wire';
 export { default } from 'x/wire';
-export * from 'x/wire';
diff --git a/packages/@lwc/ssr-compiler/src/__tests__/fixtures.spec.ts b/packages/@lwc/ssr-compiler/src/__tests__/fixtures.spec.ts
index bc8aa372ad..7f2c82a91f 100644
--- a/packages/@lwc/ssr-compiler/src/__tests__/fixtures.spec.ts
+++ b/packages/@lwc/ssr-compiler/src/__tests__/fixtures.spec.ts
@@ -13,13 +13,10 @@ import { testFixtureDir, formatHTML } from '@lwc/test-utils-lwc-internals';
 import { serverSideRenderComponent } from '@lwc/ssr-runtime';
 import { DEFAULT_SSR_MODE, type CompilationMode } from '@lwc/shared';
 import { expectedFailures } from './utils/expected-failures';
-import type { FeatureFlagName } from '@lwc/features/dist/types';
 
 interface FixtureModule {
-    tagName: string;
-    default: any;
-    props?: { [key: string]: any };
-    features?: FeatureFlagName[];
+    default: Parameters<typeof serverSideRenderComponent>[1];
+    props?: { [key: string]: unknown };
 }
 
 vi.setConfig({ testTimeout: 10_000 /* 10 seconds */ });
@@ -102,7 +99,7 @@ describe.concurrent('fixtures', () => {
                 };
             }
 
-            const module = (await import(compiledFixturePath)) as FixtureModule;
+            const { default: module } = (await import(compiledFixturePath)) as FixtureModule;
 
             let result;
             let error;
@@ -110,8 +107,8 @@ describe.concurrent('fixtures', () => {
             try {
                 result = formatHTML(
                     await serverSideRenderComponent(
-                        module!.tagName,
-                        module!.default,
+                        'fixture-test',
+                        module,
                         config?.props ?? {},
                         SSR_MODE
                     )