From 519e01952a9ebb79cadb286170d33279a7fb4f2a Mon Sep 17 00:00:00 2001
From: Charles Lyding <19598772+clydin@users.noreply.github.com>
Date: Mon, 28 Sep 2026 14:54:52 -0400
Subject: [PATCH] refactor(@angular/build): lazy load sourcemap remapping in
 i18n inliner worker

Previously, `@ampproject/remapping` was statically imported at the top level
of `i18n-inliner-worker.ts`, eagerly pulling in 5 packages
(`@ampproject/remapping` and 4 sub-dependencies) upon worker initialization.

In typical workflows or when sourcemaps are not requested for inlining,
remapping is never executed.

This changes the import of `@ampproject/remapping` to be dynamic so that
it is only loaded when a file actually requires sourcemap remapping.
---
 packages/angular/build/src/tools/i18n/i18n-inliner-worker.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/angular/build/src/tools/i18n/i18n-inliner-worker.ts b/packages/angular/build/src/tools/i18n/i18n-inliner-worker.ts
index f0bd270dc56c..66eaf23ca974 100644
--- a/packages/angular/build/src/tools/i18n/i18n-inliner-worker.ts
+++ b/packages/angular/build/src/tools/i18n/i18n-inliner-worker.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import remapping, { type DecodedSourceMap, type SourceMapInput } from '@ampproject/remapping';
+import { type DecodedSourceMap, type SourceMapInput } from '@ampproject/remapping';
 import {
   type ɵParsedTranslation,
   ɵisMissingTranslationError,
@@ -156,6 +156,8 @@ const deserializedTranslations = new Map<string, Promise<Record<string, ɵParsed
  */
 let currentGeneration: number | undefined;
 
+let remapping: typeof import('@ampproject/remapping').default | undefined;
+
 /**
  * Retrieves the file data for a filename, loading and extracting localization metadata.
  * If `cache` is true, the result is cached in `fileDataCache` across requests in this Worker.
@@ -558,6 +560,7 @@ async function inlineLocalize(
       includeContent: true,
       hires: 'boundary',
     });
+    remapping ??= (await import('@ampproject/remapping')).default;
     outputMap = remapping([{ ...rawMap, version: 3 } satisfies DecodedSourceMap, map], () => null);
   }