fix(transformer): remove stale enum member bindings#24272
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Pull request overview
This PR updates Oxc’s post-TypeScript-transform semantic cleanup to also remove enum-member bindings, which are represented as bindings during semantic analysis but don’t correspond to emitted JavaScript declarations after TS lowering. This aligns “after transform” scoping with the semantics rebuilt from the emitted JS and reduces conformance snapshot mismatches (notably fixing discriminatedUnionTypes4.ts).
Changes:
- Extend
Scoping::delete_typescript_bindingsto deleteSymbolFlags::EnumMemberbindings during the final TypeScript cleanup. - Update transformer/coverage snapshots to reflect the reduced bindings mismatches and improved pass counts across TS-related suites.
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Copilot reviewed 3 out of 6 changed files in this pull request and generated 1 comment.
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| File | Description |
|---|---|
| tasks/transform_conformance/snapshots/oxc.snap.md | Snapshot updates reflecting fewer enum-member binding mismatches in TS transform conformance. |
| tasks/transform_conformance/snapshots/babel.snap.md | Snapshot updates reflecting fewer enum-member binding mismatches in Babel TS transform conformance. |
| tasks/coverage/snapshots/semantic_typescript.snap | Coverage snapshot updates reflecting fewer TS semantic binding mismatches (including enum cases). |
| tasks/coverage/snapshots/semantic_misc.snap | Coverage snapshot updates reflecting fewer semantic binding mismatches in misc fixtures. |
| tasks/coverage/snapshots/semantic_babel.snap | Coverage snapshot updates reflecting fewer semantic binding mismatches in Babel fixtures involving enums. |
| crates/oxc_semantic/src/scoping.rs | Add SymbolFlags::EnumMember to the TypeScript binding cleanup filter. |
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## Summary Remove TypeScript enum-member bindings after transformation. Enum members are represented as bindings during semantic analysis so the transformer can resolve member values, fold references, and handle merged enums. Once TypeScript transformation finishes, those bindings no longer correspond to emitted JavaScript declarations. Include `EnumMember` in the existing final TypeScript binding cleanup instead of removing bindings during enum lowering, where later references may still need them. This fixes `discriminatedUnionTypes4.ts` and removes the same stale binding mismatch from other enum cases.
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### 🚀 Features - 616bfa2 minifier: Remove unreachable code after terminating statements (#24441) (Dunqing) - ddab89a data_structures: Add `likely` and `unlikely` functions (#24368) (overlookmotel) - a3a39f9 react_compiler: Implement enableEmitHookGuards codegen (#24329) (Boshen) - b79eef7 minifier: Apply De Morgan's law to negated comparison chains in jump guards and loop tests (#24279) (Dunqing) - 34ff7b4 minifier: Drop write-only property assignments to unused local bindings by default (#24112) (Dunqing) - 1b829d8 semantic: Record const enums in EnumData (#24268) (Dunqing) - ba0944c semantic: Add `Scoping::set_symbol_span` (#24221) (camc314) ### 🐛 Bug Fixes - 7d33363 minifier: Preserve guaranteed throws from class heritage evaluation (#24349) (Dunqing) - 058a62f semantic: Track ambient contexts in `SemanticBuilder` (#24327) (camc314) - 721eb0b transformer/decorator: Scope accessor class binding (#24330) (camc314) - 1ebdce3 semantic: Allow reserved keywords in ambient declaration types (#24325) (camc314) - 460176a track-memory-allocations: Exclude arena chunks from Sys allocs (#24292) (Dunqing) - af4922b transformer: Clear lowered namespace redeclarations (#24300) (camc314) - ffd2765 semantic: Mark declared computed `MethodDefinition`s as type references (#24296) (camc314) - f17514b isolated-declarations: Emit const readonly fields as types (#24288) (camc314) - 40f769d minifier: Make `__proto__` write tracking execution-order independent (#24280) (Dunqing) - 6371fed transformer: Remove stale enum member bindings (#24272) (camc314) - f05dfab transformer: Correct symbol flags for lowered namespaces (#24271) (Dunqing) - 84eeb55 transformer: Correct symbol flags for lowered enums (#24269) (Dunqing) - c3057da transformer: Preserve generated class binding spans (#24220) (camc314) - 8260096 transformer: Correct span for lowered namespace symbol (#24222) (camc314) - 42d00d3 semantic: Mark declared class heritage as type references (#24237) (camc314) - 588d997 semantic: Mark TS `PropertyDefinition`s computed fields as type references (#24233) (camc314) - 9b95632 semantic: Mark computed method keys in `TSMethodSignature`s as type references (#24232) (camc314) ### ⚡ Performance - 5b26643 transformer_plugins: Dispatch global defines by trailing name (#23666) (Boshen) - dce0f29 react_compiler: Replace all compiled functions in a single AST walk (#24403) (Boshen) - f85f0d8 ast: Delegate inherited enum variants in clone_in and estree derives (#23555) (Boshen) - 3ff0234 allocator: Remove `unwrap` from `ReplaceWith` (#24365) (overlookmotel) - ab22e80 transformer: Fix Rust 1.97 performance regression (#24354) (camc314) - b47585c parser: Use `ReplaceWith` instead of `TakeIn` (#24018) (overlookmotel) - b227a06 minifier: Use `ReplaceWith` instead of `TakeIn` (#24017) (overlookmotel) Co-authored-by: Boshen <[email protected]>
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Summary
Remove TypeScript enum-member bindings after transformation.
Enum members are represented as bindings during semantic analysis so the transformer can resolve member values, fold references, and handle merged enums. Once TypeScript transformation finishes, those bindings no longer correspond to emitted JavaScript declarations.
Include
EnumMemberin the existing final TypeScript binding cleanup instead of removing bindings during enum lowering, where later references may still need them.This fixes
discriminatedUnionTypes4.tsand removes the same stale binding mismatch from other enum cases.