fix(rsc): handle conflict names from export * in use client and use server modules

[hi-ogawa]

Description

• Follow up to fix(rsc): handle export * re-exports in use client and use server modules #1234
• review plan https://gist.github.com/hi-ogawa/cf434aff19cc869e6cfae366851db0c7

This PR extracts export * expansion into a dedicated transform with file fixtures based unti tests and tightens its handling of ESM star-export ambiguity before downstream proxy/wrap transforms run.

It turned out export * semantics have many edge cases and some cases are explicitly not handled yet but kept as test cases with TODOs, for example:

• Support duplicate export * entries that resolve to the same underlying binding instead of treating them as ambiguous.
• Support duplicate namespace re-exports that resolve to the same namespace binding.
• Replace the current cycle bailout with per-name/per-binding resolution so cyclic star exports that resolve to the same binding can survive.
• Support string-literal export names instead of rejecting them.
• Preserve/compose source maps for the pre-rewrite transform.

[Copilot]

Pull request overview

This PR improves @vitejs/plugin-rsc’s handling of export * from ... inside "use client" and "use server" modules by introducing a pre-transform that expands bare star re-exports into explicit named re-exports, including logic to avoid re-exporting ambiguous/conflicting names (per ESM rules). It also adds/updates tests and fixtures around export scanning/expansion and tightens behavior for unsupported string-literal export names.

Changes:

• Add transformExpandExportAll to recursively scan dependencies and rewrite bare export * from into explicit export { ... } from before proxy/wrap transforms run.
• Update proxy/wrap transforms to throw a clearer error for string-literal export names.
• Add unit fixtures/tests and an e2e route/test covering "use server" + export * server actions.

Reviewed changes

Copilot reviewed 76 out of 76 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
packages/plugin-rsc/src/transforms/wrap-export.ts	Throw clearer error for string-literal export names; simplify ExportAllDeclaration handling.
packages/plugin-rsc/src/transforms/wrap-export.test.ts	Add test for string-literal export-name error; adjust export * as snapshot expectation.
packages/plugin-rsc/src/transforms/utils.ts	Remove getExportNames helper (no longer used).
packages/plugin-rsc/src/transforms/proxy-export.ts	Throw clearer error for string-literal export names.
packages/plugin-rsc/src/transforms/proxy-export.test.ts	Add test for string-literal export-name error.
packages/plugin-rsc/src/transforms/index.ts	Re-export new expand-export-all transform from transforms entrypoint.
packages/plugin-rsc/src/transforms/expand-export-all.ts	New recursive scanner/rewriter to expand bare export * into explicit named re-exports with conflict/ambiguity handling.
packages/plugin-rsc/src/transforms/expand-export-all.test.ts	Fixture-driven tests validating transformExpandExportAll rewrites and error cases.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/string-export-name/entry.js.snap.js	Snapshot for string-literal export-name error case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/string-export-name/entry.js	Fixture entry for string-literal export-name error case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/string-export-name/dep.js	Fixture dependency exporting a string-literal export name.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/no-export-star/entry.js.snap.js	Snapshot for “no bare export-star to expand” case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/no-export-star/entry.js	Fixture with export * as ns (should not be rewritten).
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/no-export-star/dep.js	Fixture dep for “no-export-star” case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-filtered-conflict/repro2.js	Extra repro script for conflict behavior notes.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-filtered-conflict/repro1.js	Extra repro script for Node/V8 behavior notes.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-filtered-conflict/entry.js.snap.js	Snapshot for nested filtered conflict expansion.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-filtered-conflict/entry.js	Fixture entry re-exporting from two deps.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-filtered-conflict/dep2.js	Fixture dep with nested export * chain.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-filtered-conflict/dep2-2.js	Fixture leaf dep for nested chain.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-filtered-conflict/dep2-1.js	Fixture leaf dep for nested chain.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-filtered-conflict/dep1.js	Fixture dep for nested conflict case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-star/entry.js.snap.js	Snapshot for nested conflict-star expansion.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-star/entry.js	Fixture entry with export * to dep that re-exports conflicting names.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-star/dep.js	Fixture dep that star-exports from two modules.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-star/b.js	Fixture leaf module.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-star/a.js	Fixture leaf module.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-explicit-reexport-wins/override.js	Fixture override module for explicit re-export precedence.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-explicit-reexport-wins/middle.js	Fixture middle module combining star + explicit re-export.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-explicit-reexport-wins/entry.js.snap.js	Snapshot for explicit re-export precedence through nesting.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-explicit-reexport-wins/entry.js	Fixture entry for precedence case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-explicit-reexport-wins/dep.js	Fixture dep with star re-exports.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-explicit-reexport-wins/b.js	Fixture leaf module.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/nested-conflict-explicit-reexport-wins/a.js	Fixture leaf module.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/namespace-same-binding/entry.js.snap.js	Snapshot capturing current limitation for same-binding namespace duplication.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/namespace-same-binding/entry.js	Fixture entry for same-binding namespace duplication.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/namespace-same-binding/dep2.js	Fixture dep exporting namespace from same target.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/namespace-same-binding/dep1.js	Fixture dep exporting namespace from same target.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/namespace-same-binding/dep-target.js	Shared target module for namespace exports.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/explicit-wins/entry.js.snap.js	Snapshot for explicit local export shadowing star export.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/explicit-wins/entry.js	Fixture entry for explicit-shadowing case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/explicit-wins/dep.js	Fixture dep for explicit-shadowing case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/duplicate-star-same-source/entry.js.snap.js	Snapshot capturing current limitation for duplicate star exports from same source.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/duplicate-star-same-source/entry.js	Fixture entry repeating the same export * from multiple times.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/duplicate-star-same-source/dep.js	Fixture dep for duplicate-star case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/default-only/entry.js.snap.js	Snapshot for star re-export of default-only module (results in empty named re-export).
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/default-only/entry.js	Fixture entry for default-only case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/default-only/dep.js	Fixture dep exporting only default (plus side effects).
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/conflict-star/entry.js.snap.js	Snapshot for conflicting names across multiple star sources.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/conflict-star/entry.js	Fixture entry for conflict-star case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/conflict-star/b.js	Fixture leaf module.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/conflict-star/a.js	Fixture leaf module.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/circular/entry.js.snap.js	Snapshot for circular star export graph case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/circular/entry.js	Fixture entry for circular case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/circular/dep2.js	Fixture dep in circular chain.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/circular/dep1.js	Fixture dep in circular chain.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/circular-same-binding/entry.js.snap.js	Snapshot capturing current limitation for cyclic same-binding case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/circular-same-binding/entry.js	Fixture entry for cyclic same-binding case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/circular-same-binding/b.js	Fixture dep in cyclic case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/circular-same-binding/a.js	Fixture dep in cyclic case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/basic/nested.js	Fixture nested module exporting a class.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/basic/entry.js.snap.js	Snapshot for basic expansion (incl. namespace + nested star).
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/basic/entry.js	Fixture entry for basic expansion.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/basic/dep.js	Fixture dep combining explicit exports, default re-export, star, and namespace export.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/basic/default.js	Fixture default-export module.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/bad-resolve/entry.js.snap.js	Snapshot for “failed to resolve” error.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/bad-resolve/entry.js	Fixture entry for “bad resolve” case.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/bad-load/entry.js.snap.js	Snapshot for “failed to load” error.
packages/plugin-rsc/src/transforms/fixtures/expand-export-all/bad-load/entry.js	Fixture entry for “bad load” case.
packages/plugin-rsc/src/plugin.ts	Use transformExpandExportAll in both use client and use server plugin transforms.
packages/plugin-rsc/examples/basic/src/routes/root.tsx	Wire new example route into the basic example app.
packages/plugin-rsc/examples/basic/src/routes/action-export-all/server.tsx	New server component exercising use server + export * server actions.
packages/plugin-rsc/examples/basic/src/routes/action-export-all/client.tsx	New client component invoking server action through expanded re-export.
packages/plugin-rsc/examples/basic/src/routes/action-export-all/actions.ts	use server module that re-exports actions via bare export *.
packages/plugin-rsc/examples/basic/src/routes/action-export-all/action-impl.ts	Action implementations to be re-exported and registered.
packages/plugin-rsc/e2e/basic.test.ts	Add e2e coverage for use server + export *; rename existing “export *” test label.

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[Copilot]

Pull request overview

Copilot reviewed 76 out of 76 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (2)

packages/plugin-rsc/src/transforms/wrap-export.ts:193

• transformWrapExport no longer handles export * as ns from "..." (ExportAllDeclaration with exported identifier). This is still a valid ESM form and is already supported by transformProxyExport; dropping support here will make use server wrapping (transformServerActionServer -> transformWrapExport) throw unsupported ExportAllDeclaration for namespace re-exports.
  packages/plugin-rsc/src/transforms/proxy-export.ts:118
• expand-export-all can rewrite a star export into export {} from "..." to preserve side effects when no names are safely re-exportable. transformProxyExport currently treats any ExportNamedDeclaration with specifiers as something to replace with proxy exports; when specifiers is empty it replaces the whole statement with an empty string, dropping the side-effect-only re-export. export {} from should be left intact.

[hi-ogawa]

This was reverted since this change was irrelevant for original PR

• fix(rsc): handle export * re-exports in use client and use server modules #1234 (comment)