refactor(@angular/build): lazy load sourcemap remapping in js transform worker - #34191
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…rm worker Previously, `@ampproject/remapping` was statically imported at the top level of `javascript-transformer-worker.ts`, eagerly pulling in 5 packages (`@ampproject/remapping` and 4 sub-dependencies) upon worker initialization. In standard Angular CLI configurations (`ng build` and `ng serve`), vendor sourcemaps are disabled by default (`thirdPartySourcemaps = false`), causing `useInputSourcemap` to evaluate to false for all transformed `node_modules` files. As a result, sourcemap remapping is never executed in typical builds.
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This pull request refactors the @ampproject/remapping import in javascript-transformer-worker.ts to be loaded lazily. The top-level import is converted to a type-only import, and the module is dynamically imported and cached only when it is needed. I have no feedback to provide as there are no review comments.
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Sep 28, 2026
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Previously,
@ampproject/remappingwas statically imported at the top level ofjavascript-transformer-worker.ts, eagerly pulling in 5 packages (@ampproject/remappingand 4 sub-dependencies) upon worker initialization.In standard Angular CLI configurations (
ng buildandng serve), vendor sourcemaps are disabled by default (thirdPartySourcemaps = false), causinguseInputSourcemapto evaluate to false for all transformednode_modulesfiles. As a result, sourcemap remapping is never executed in typical builds.