refactor(@angular/build): pass missingTranslation per request in i18n inliner

Remove workerData from the i18n inliner worker pool initialization and pass missingTranslation per task in the request payload.

This decouples the worker pool from inliner-specific options, allowing worker threads to be safely shared without hardcoding the missingTranslation handling behavior at pool creation time.

Author: clydin

packages/angular/build/src/tools/esbuild/i18n-inliner-worker.ts

@@ -12,7 +12,6 @@ import type { Node } from '@oxc-project/types';
 import { MagicString } from 'magic-string';
 import assert from 'node:assert';
 import { deserialize } from 'node:v8';
-import { workerData } from 'node:worker_threads';
 import { parseSync } from 'oxc-parser';
 import { traversePostOrder } from '../oxc/traversal';
 import { loadLocaleData } from './i18n-locale-plugin';
@@ -43,6 +42,11 @@ export interface InlineCodeRequest {
    * the Worker by reference instead of being copied into it for every request.
    */
   translation?: Blob | SharedArrayBuffer;
+
+  /**
+   * How to handle missing translations.
+   */
+  missingTranslation?: 'error' | 'warning' | 'ignore';
 }
 
 /**
@@ -77,6 +81,11 @@ export interface InlineFileBatchRequest {
    */
   locales: ReadonlyMap<string, Blob | SharedArrayBuffer | undefined>;
 
+  /**
+   * How to handle missing translations.
+   */
+  missingTranslation?: 'error' | 'warning' | 'ignore';
+
   /**
    * Whether the file data should be treated as ephemeral and not cached long-term in the Worker.
    * Typically true when all remaining locales for the file are processed in a single batch.
@@ -121,11 +130,6 @@ export type InlineFileBatchResult =
       results: InlineLocaleResult[];
     };
 
-// Extract common options used for inline requests from the Worker context
-const { missingTranslation } = (workerData || {}) as {
-  missingTranslation: 'error' | 'warning' | 'ignore';
-};
-
 /**
  * Cached file data including code and extracted localization metadata.
  */
@@ -276,6 +280,7 @@ export async function inlineFileBatch(
         locale,
         await loadTranslation(locale, translation),
         request.filename,
+        request.missingTranslation,
       );
 
       return {
@@ -309,6 +314,7 @@ export async function inlineCode(request: InlineCodeRequest): Promise<InlineCode
     request.locale,
     await loadTranslation(request.locale, request.translation),
     request.filename,
+    request.missingTranslation,
   );
 
   return {
@@ -448,6 +454,7 @@ function escapeTemplatePart(part: string): string {
  * @param locale The target locale identifier.
  * @param translation The translation messages dictionary, or undefined for untranslated locale.
  * @param filename The name of the file being transformed.
+ * @param missingTranslation How to handle missing translations.
  * @returns The transformed code, optional remapped source map, and diagnostics.
  */
 async function inlineLocalize(
@@ -457,6 +464,7 @@ async function inlineLocalize(
   locale: string,
   translation: Record<string, ɵParsedTranslation> | undefined,
   filename: string,
+  missingTranslation: 'error' | 'warning' | 'ignore' = 'warning',
 ) {
   const magicString = new MagicString(code);
   const { Diagnostics, translate } = await loadLocalizeTools();

packages/angular/build/src/tools/esbuild/i18n-inliner.ts

@@ -186,15 +186,9 @@ export class I18nInliner {
     private readonly options: I18nInlinerOptions,
     maxThreads?: number,
   ) {
-    const { missingTranslation } = options;
-
     this.#workerPool = new WorkerPool({
       filename: require.resolve('./i18n-inliner-worker'),
       maxThreads,
-      // Extract options to ensure only the named options are serialized and sent to the worker
-      workerData: {
-        missingTranslation,
-      },
     });
   }
 
@@ -514,6 +508,7 @@ export class I18nInliner {
             code: codeBlob,
             map: mapBlob,
             locales: new Map(batchEntries.map((e) => [e.locale, e.translation])),
+            missingTranslation: this.options.missingTranslation,
             ephemeral,
             activeLocales,
             generation,
@@ -613,6 +608,7 @@ export class I18nInliner {
       code: templateCode,
       filename: templateId,
       locale,
+      missingTranslation: this.options.missingTranslation,
       translation: await serializeTranslation(
         translation,
         translationIntegrity,

packages/angular/build/src/tools/esbuild/i18n-inliner_spec.ts

@@ -144,6 +144,31 @@ describe('I18nInliner', () => {
     expect(findFile(outputFiles, 'main.js').text).toContain('"Hello"');
   });
 
+  it('errors and retains the original message when missingTranslation is "error"', async () => {
+    const { outputFiles, errors, warnings } = await createInliner({
+      missingTranslation: 'error',
+    }).inlineForLocale([browserFile('main.js', GREETING_SOURCE)], 'fr', {
+      unrelated: translationFor('Sans rapport'),
+    });
+
+    expect(errors.length).toBe(1);
+    expect(errors[0]).toContain('greeting');
+    expect(warnings).toEqual([]);
+    expect(findFile(outputFiles, 'main.js').text).toContain('"Hello"');
+  });
+
+  it('ignores missing translations when missingTranslation is "ignore"', async () => {
+    const { outputFiles, errors, warnings } = await createInliner({
+      missingTranslation: 'ignore',
+    }).inlineForLocale([browserFile('main.js', GREETING_SOURCE)], 'fr', {
+      unrelated: translationFor('Sans rapport'),
+    });
+
+    expect(errors).toEqual([]);
+    expect(warnings).toEqual([]);
+    expect(findFile(outputFiles, 'main.js').text).toContain('"Hello"');
+  });
+
   it('replaces the locale placeholder with the locale being inlined', async () => {
     // The placeholder is only inlined for files that use `$localize`, which is where the build
     // inserts it, so the message is present alongside it here.