fix(ExportsFieldPlugin): prevent fallback to parent node_modules when exports target is missing#495
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alexander-akait merged 1 commit intomainfrom Mar 17, 2026
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… exports target is missing When a package's exports field maps a request to a target file that does not exist on disk, resolution was incorrectly falling back to parent node_modules directories. This violated the Node.js ESM spec (issue #399). Root cause: ExportsFieldPlugin returned null on failure, which Resolver.doResolve converted to undefined, signalling ModulesInHierarchicalDirectoriesPlugin to continue searching up the directory tree instead of stopping. Fix: return an explicit error from the exports field processing callback when a match was found but no valid target file could be resolved, preventing any further directory traversal. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
🦋 Changeset detectedLatest commit: 92c497e The changes in this PR will be included in the next version bump. This PR includes changesets to release 1 package
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #495 +/- ##
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+ Coverage 93.42% 93.43% +0.01%
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Files 50 50
Lines 2511 2515 +4
Branches 766 767 +1
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+ Hits 2346 2350 +4
Misses 136 136
Partials 29 29
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alexander-akait
approved these changes
Mar 17, 2026
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Summary
fixes #399
When a package's exports field maps a request to a target file that does not exist on disk, resolution was incorrectly falling back to parent node_modules directories. This violated the Node.js ESM spec (issue #399).
Root cause: ExportsFieldPlugin returned null on failure, which Resolver.doResolve converted to undefined, signalling ModulesInHierarchicalDirectoriesPlugin to continue searching up the directory tree instead of stopping.
Fix: return an explicit error from the exports field processing callback when a match was found but no valid target file could be resolved, preventing any further directory traversal.
What kind of change does this PR introduce?
fix
Did you add tests for your changes?
Yes
Does this PR introduce a breaking change?
No
If relevant, what needs to be documented once your changes are merged or what have you already documented?
Nothing
Use of AI
Partial