@W-17592100 chore: run unit tests in production mode (#5270)

* ci: run unit tests in prod mode

* test(engine-dom): skip testing dev mode feature in prod mode

* test(ssr-compiler): avoid checking dev mode error text in prod mode

* test(engine-server): skip fixture tests in prod mode

there are a lot of failures that we'll get to later

* chore(tests): support NODE_ENV=production

* Apply suggestions from code review

* chore(coverage): bump minimum function threshold for SSR packages

* chore: remove unused file

* test(coverage): ignore ssr-client-utils and bump thresholds for SSR

* ci: don't generate coverage for prod mode

Coverage will always be lower because we have a ton of
`NODE_ENV !== production checks`, but no `===` checks.

---------

Co-authored-by: Matheus Cardoso <[email protected]>

.github/workflows/unit.yml

@@ -66,6 +66,8 @@ jobs:
               run: yarn test:types
             - name: Run unit tests
               run: yarn test:ci
+            - name: Run unit tests in production mode
+              run: yarn test:production --no-watch
             - name: Upload unit test coverage report
               uses: actions/upload-artifact@v4
               with:

package.json

@@ -19,6 +19,7 @@
         "copy-fork": "./scripts/tasks/unsafe-external-contributor-ci-workaround.sh",
         "dev": "nx run-many --target=dev --all --parallel=999 --exclude=@lwc/perf-benchmarks,@lwc/perf-benchmarks-components,@lwc/integration-tests",
         "test": "vitest --workspace vitest.workspace.mjs",
+        "test:production": "VITE_NODE_ENV=production vitest --workspace vitest.workspace.mjs",
         "test:bespoke": "nx run-many --target=test",
         "test:debug": "vitest --workspace vitest.workspace.mjs --inspect-brk --no-file-parallelism",
         "test:ci": "vitest run --workspace vitest.workspace.mjs --coverage",

packages/@lwc/engine-dom/src/formatters/__tests__/component.spec.ts

@@ -15,7 +15,7 @@ import {
 import { LOWEST_API_VERSION } from '@lwc/shared';
 
 // it needs to be imported from the window, otherwise the checks for associated vms is done against "@lwc/engine-core"
-const LightningElementFormatter = (globalThis as any)['devtoolsFormatters'].find((f: any) => {
+const LightningElementFormatter = (globalThis as any)['devtoolsFormatters']?.find((f: any) => {
     return f.name === 'LightningElementFormatter';
 });
 
@@ -33,8 +33,9 @@ class WireAdapter {
     disconnect() {}
 }
 
-describe('Lightning Element formatter', () => {
-    const { header } = LightningElementFormatter;
+// LightningElementFormatter is not exposed in prod mode
+describe.skipIf(process.env.NODE_ENV === 'production')('Lightning Element formatter', () => {
+    const header = LightningElementFormatter?.header;
 
     it('should not contain body', () => {
         expect(LightningElementFormatter.hasBody()).toBe(false);

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

@@ -13,6 +13,7 @@ import { testFixtureDir, formatHTML, pluginVirtual } from '@lwc/test-utils-lwc-i
 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 { FeatureFlagName } from '@lwc/features/dist/types';
 
 vi.mock('lwc', async () => {
     const lwcEngineServer = await import('../index');
@@ -33,6 +34,9 @@ interface FixtureConfig {
 
     /** Props to provide to the root component. */
     props?: Record<string, string>;
+
+    /** Feature flags to enable for the test. */
+    features: FeatureFlagName[];
 }
 
 async function compileFixture({
@@ -162,7 +166,8 @@ function testFixtures(options?: RollupLwcOptions) {
     );
 }
 
-describe.concurrent('fixtures', () => {
+// TODO [#5134]: Enable these tests in production mode
+describe.skipIf(process.env.NODE_ENV === 'production').concurrent('fixtures', () => {
     beforeAll(() => {
         // ENABLE_WIRE_SYNC_EMIT is used because this mimics the behavior for LWR in SSR mode. It's also more reasonable
         // for how both `engine-server` and `ssr-runtime` behave, which is to use sync rendering.

packages/@lwc/ssr-compiler/src/__tests__/estemplate.spec.ts

@@ -61,7 +61,7 @@ describe.each(
                 `;
             const doReplacement = () => tmpl(b.literal('I am not an identifier') as any);
             expect(doReplacement).toThrow(
-                'Validation failed for templated node. Expected type identifier, but received Literal.'
+                /^Validation failed for templated node\. Expected type .+?, but received Literal\.$/
             );
         });
     });

packages/@lwc/ssr-runtime/src/stubs.ts

@@ -5,6 +5,8 @@
  * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/MIT
  */
 
+/* v8 ignore start */
+
 // Stubs for all the un-implemented exports from @lwc/engine-server
 
 export function api(..._: unknown[]): never {
@@ -216,3 +218,5 @@ export const renderer = {
  */
 // A real stub, not a "not implemented" one! 😯
 export const hot = undefined;
+
+/* v8 ignore stop */

vitest.config.mjs

@@ -22,6 +22,8 @@ export default defineConfig({
                 '**/packages/@lwc/engine-dom/**',
                 '**/packages/@lwc/engine-core/**',
                 '**/packages/@lwc/synthetic-shadow/**',
+                // TODO [#5272]: add tests
+                '**/packages/@lwc/ssr-client-utils/**',
                 // Ignore test packages
                 '**/packages/@lwc/integration-karma/**',
                 '**/packages/@lwc/integration-tests/**',
@@ -36,9 +38,9 @@ export default defineConfig({
                 // SSR compiler/runtime is relatively newer, so has lower thresholds for now
                 '**/packages/@lwc/ssr-*/**': {
                     branches: 90,
-                    functions: 60,
-                    lines: 85,
-                    statements: 85,
+                    functions: 90,
+                    lines: 90,
+                    statements: 90,
                 },
 
                 '!**/packages/@lwc/ssr-*/**': {

vitest.shared.mjs

@@ -1,9 +1,14 @@
 import inspector from 'node:inspector';
+import process from 'node:process';
 import { defineConfig } from 'vitest/config';
 import pkg from './package.json';
-
 export default defineConfig({
     test: {
+        // We can't set `NODE_ENV` directly (i.e. `NODE_ENV=production yarn test`), because some packages
+        // set their env to jsdom, and NODE_ENV=production + jsdom causes `node:` imports to break
+        env: {
+            NODE_ENV: process.env.VITE_NODE_ENV,
+        },
         // Don't time out if we detect a debugger attached
         testTimeout: inspector.url()
             ? // Largest allowed delay, see https://developer.mozilla.org/en-US/docs/Web/API/Window/setTimeout#maximum_delay_value
@@ -28,6 +33,7 @@ export default defineConfig({
                 'rollup-plugin',
                 'shared',
                 'signals',
+                'ssr-client-utils',
                 'ssr-compiler',
                 'ssr-runtime',
                 'style-compiler',