perf(@angular/build): avoid encoding intermediate source maps before remapping - #33779
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alan-agius4 merged 1 commit intoAug 6, 2026
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…remapping Use `generateDecodedMap()` instead of `generateMap()` when intermediate source maps created with `MagicString` are immediately remapped via `@ampproject/remapping`. This applies to: - `oxc-transform`: when an input source map is present - `oxc-linker`: when an input source map is present - Sass URL rebasing: intermediate stylesheet rebase maps stored for Sass source map merging Bypassing VLQ base64 encoding and immediate decoding reduces CPU time and temporary memory allocations during source map generation.
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This pull request optimizes sourcemap generation and remapping across several build tools (including the OXC linker, OXC transform, and Sass rebasing importer) by switching from encoded sourcemaps to decoded sourcemaps (DecodedSourceMap). By utilizing generateDecodedMap instead of generateMap when an input sourcemap is present, it avoids unnecessary encoding and decoding overhead. Additionally, corresponding unit tests have been added to verify sourcemap generation and remapping behavior. There are no review comments, so I have no feedback to provide.
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target: minor
alan-agius4
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Aug 6, 2026
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Use
generateDecodedMap()instead ofgenerateMap()when intermediate source maps created withMagicStringare immediately remapped via@ampproject/remapping.This applies to:
oxc-transform: when an input source map is presentoxc-linker: when an input source map is presentBypassing VLQ base64 encoding and immediate decoding reduces CPU time and temporary memory allocations during source map generation.