test(fixtures): eradicate index.js (#5222)

* refactor: create rollup plugin for virtual modules

* test(fixtures): refactor fixture config defs to individual files

they're not actually shared

* test(fixtures): update to use config.json instead of index.js

* chore: eradicate index.js

* chore: fix file extension

* chore: oops forgot this part

Author: wjhsf

.github/workflows/unit.yml

@@ -53,7 +53,7 @@ jobs:
             - name: Check licenses are up to date
               run: node ./scripts/tasks/generate-license-files.js --test
             - name: Verify @lwc/shared is tree-shakable
-              run: node ./scripts/tasks/verify-treeshakable.js ./packages/@lwc/shared/dist/index.js
+              run: node ./scripts/tasks/verify-treeshakable.mjs ./packages/@lwc/shared/dist/index.js
             - name: Verify that dependencies are declared
               run: node ./scripts/tasks/check-imports-are-declared-dependencies.js
             - name: Check formatting

.husky/pre-push

@@ -1,5 +1,5 @@
 set -e
 node ./scripts/tasks/check-and-rewrite-package-json.js --test
 node ./scripts/tasks/generate-license-files.js --test
-node ./scripts/tasks/verify-treeshakable.js ./packages/@lwc/shared/dist/index.js
+node ./scripts/tasks/verify-treeshakable.mjs ./packages/@lwc/shared/dist/index.js
 node ./scripts/tasks/check-imports-are-declared-dependencies.js

packages/@lwc/babel-plugin-component/src/__tests__/index.spec.ts

@@ -9,7 +9,7 @@ import { describe } from 'vitest';
 import { transformSync } from '@babel/core';
 import { LWC_VERSION, HIGHEST_API_VERSION } from '@lwc/shared';
 import { testFixtureDir } from '@lwc/test-utils-lwc-internals';
-import plugin from '../index';
+import plugin, { type LwcBabelPluginOptions } from '../index';
 
 const BASE_OPTS = {
     namespace: 'lwc',
@@ -62,7 +62,7 @@ function transform(source: string, opts = {}) {
 }
 
 describe('fixtures', () => {
-    testFixtureDir(
+    testFixtureDir<LwcBabelPluginOptions>(
         {
             root: path.resolve(__dirname, 'fixtures'),
             pattern: '**/actual.js',

packages/@lwc/engine-server/src/__tests__/fixtures.spec.ts

@@ -9,36 +9,38 @@ import path from 'node:path';
 import { vi, describe, beforeAll, afterAll } from 'vitest';
 import { rollup } from 'rollup';
 import lwcRollupPlugin from '@lwc/rollup-plugin';
-import { testFixtureDir, formatHTML } from '@lwc/test-utils-lwc-internals';
+import { testFixtureDir, formatHTML, pluginVirtual } from '@lwc/test-utils-lwc-internals';
 import { setFeatureFlagForTest } from '../index';
+import type { LightningElementConstructor } from '@lwc/engine-core/dist/framework/base-lightning-element';
 import type { RollupLwcOptions } from '@lwc/rollup-plugin';
-import type * as lwc from '../index';
-
-interface FixtureModule {
-    default: typeof lwc.LightningElement;
-    props?: { [key: string]: unknown };
-}
 
 vi.mock('lwc', async () => {
     const lwcEngineServer = await import('../index');
     try {
-        lwcEngineServer.setHooks({
-            sanitizeHtmlContent(content: unknown) {
-                return content as string;
-            },
-        });
+        lwcEngineServer.setHooks({ sanitizeHtmlContent: String });
     } catch (_err) {
         // Ignore error if the hook is already overridden
     }
     return lwcEngineServer;
 });
 
+interface FixtureConfig {
+    /**
+     * Component name that serves as the entrypoint / root component of the fixture.
+     * @example x/test
+     */
+    entry: string;
+
+    /** Props to provide to the root component. */
+    props?: Record<string, string>;
+}
+
 async function compileFixture({
-    input,
+    entry,
     dirname,
     options,
 }: {
-    input: string;
+    entry: string;
     dirname: string;
     options?: RollupLwcOptions;
 }) {
@@ -48,11 +50,13 @@ async function compileFixture({
             .join('-') || 'default';
     const modulesDir = path.resolve(dirname, './modules');
     const outputFile = path.resolve(dirname, `./dist/compiled-${optionsAsString}.js`);
+    const input = 'virtual/fixture/test.js';
 
     const bundle = await rollup({
         input,
-        external: ['lwc', 'vitest'],
+        external: ['lwc', '@lwc/ssr-runtime', 'vitest'],
         plugins: [
+            pluginVirtual(`export { default } from "${entry}";`, input),
             lwcRollupPlugin({
                 enableDynamicComponents: true,
                 experimentalDynamicComponent: {
@@ -95,23 +99,23 @@ async function compileFixture({
 }
 
 function testFixtures(options?: RollupLwcOptions) {
-    testFixtureDir(
+    testFixtureDir<FixtureConfig>(
         {
             root: path.resolve(__dirname, 'fixtures'),
-            pattern: '**/index.js',
+            pattern: '**/config.json',
         },
-        async ({ filename, dirname, config }) => {
+        async ({ dirname, config }) => {
             let compiledFixturePath;
 
             try {
                 compiledFixturePath = await compileFixture({
-                    input: filename,
+                    entry: config!.entry,
                     dirname,
                     options,
                 });
             } catch (err: any) {
                 // Filter out the stacktrace, just include the LWC error message
-                const message = err?.message?.match(/(LWC\d+[^\n]+)/)?.[1];
+                const message = err?.message?.match(/(LWC\d+[^\n]+)/)?.[1] ?? err.message;
                 return {
                     'expected.html': '',
                     'error.txt': message,
@@ -128,9 +132,10 @@ function testFixtures(options?: RollupLwcOptions) {
             let result;
             let err;
             try {
-                const { default: module } = (await import(compiledFixturePath)) as FixtureModule;
+                const module: LightningElementConstructor = (await import(compiledFixturePath))
+                    .default;
                 result = formatHTML(
-                    lwcEngineServer!.renderComponent('fixture-test', module, config?.props ?? {})
+                    lwcEngineServer.renderComponent('fixture-test', module, config?.props ?? {})
                 );
             } catch (_err: any) {
                 if (_err?.name === 'AssertionError') {

packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/config.json

@@ -0,0 +1,3 @@
+{
+    "entry": "x/comments-text"
+}

packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-at-end/index.js

@@ -0,0 +1,3 @@
+{
+    "entry": "x/comments-text"
+}

packages/@lwc/engine-server/src/__tests__/fixtures/adjacent-text-nodes/preserve-comments-off/comments-then-element/config.json

@@ -0,0 +1,3 @@
+{
+    "entry": "x/comments-text"
+}