Turbopack: refactor export analysis#92781
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mischnic wants to merge 3 commits intomischnic/refactor-esm-codegenfrom
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This was referenced Apr 14, 2026
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Failing test suitesCommit: 2bec518 | About building and testing Next.js
Expand output● create-next-app with package manager yarn › should use yarn for --use-yarn flag ● create-next-app with package manager yarn › should use yarn when user-agent is yarn
Expand output● instant-navigation-testing-api › runtime params are excluded from instant shell › does not include cookie values in instant shell during page load |
Merging this PR will improve performance by 4.77%
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The refactor moved import handling to a prepass but dropped the case where
an import has no specifiers but has an internal turbopack part ID (e.g.
`import "__TURBOPACK_PART__" with { ... }`). Without this, the tree-shaken
facade loses its dependency on the ModuleEvaluation part, causing side
effects to not execute.
Co-Authored-By: Claude <[email protected]>
Two fixes in imports.rs:
1. Re-exports (export { x } from '...') should always have mutable=false
since liveness is determined by the referenced module's own export
description, not the re-exporting module. The refactor incorrectly
propagated is_fake_esm to the mutable flag for re-exports, causing
setter functions to be emitted where getters are sufficient.
2. The snapshot source-map offsets shifted by 4 lines due to the above
change; regenerate the 5 affected basic-tree-shake snapshots.
Co-Authored-By: Claude <[email protected]>
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Remove
ModuleReferencesVisitorand move everything into theImportMapAnalyzer