fix(transformer/class-properties): use correct property name when converting parameter properties#21268
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…m property name when clashing symbol is renamed When class-properties transform renames a constructor parameter to avoid shadowing (e.g. `x` -> `_x`), the BindingIdentifier.name is mutated before the TypeScript param property transform reads it. This caused `this._x = _x` instead of the correct `this.x = _x`. Use `span.source_text()` to recover the original parameter name from source, which is unaffected by the rename pass. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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### 💥 BREAKING CHANGES - 36cdc31 str: [**BREAKING**] Remove identity `FromIn` impl for `Ident` (#21251) (overlookmotel) - 382958a span: [**BREAKING**] Remove re-exports of string types from `oxc_span` crate (#21246) (overlookmotel) - c4aedfa str: [**BREAKING**] Add `static_ident!` macro (#21245) (overlookmotel) ### 🚀 Features - e7e1aea transformer/typescript: Add `optimize_enums` option for regular enum inlining (#20539) (Dunqing) - 679f57f transformer/typescript: Implement const enum inlining and declaration removal (#20508) (Dunqing) - 6dd061c semantic: Extend `MemberWriteTarget` to cover all property modification patterns (#21205) (Dunqing) - f134e24 minifier: Support `property_write_side_effects` option to drop unused property assignments (#20773) (Dunqing) - 75663c0 semantic: Add enum member value evaluation for const enum support (#20602) (Dunqing) - 3cfe8ed semantic: Add `MemberWriteTarget` flag to `ReferenceFlags` (#20772) (Dunqing) ### 🐛 Bug Fixes - af1a586 transformer/class-properties: Use correct property name when converting parameter properties (#21268) (Amal Jossy) - b43250a allocator: Move allocation tracking into `Bump` (#21342) (overlookmotel) - 36f505f allocator: `StringBuilder` use `Allocator::alloc_layout` (#21340) (overlookmotel) - 7a08a6f allocator: Fix allocation counting in `Allocator::alloc_concat_strs_array` (#21336) (overlookmotel) - 2338e28 ecmascript: Treat `this` as potentially having side effects (#21297) (sapphi-red) - bd8bd39 allocator: Remove unsafe hacks from `from_raw_parts` methods (#21283) (overlookmotel) - 8f4c340 allocator: Remove dangerous pointer const to mut cast (#21279) (overlookmotel) - aa9259f parser: Add missing error code for optional param diagnostic (#21258) (camc314) - 04b3c2f str: Fix unsound casting const pointers to mut pointers (#21242) (overlookmotel) - ceadf6c str: Make `Ident::from_raw` an unsafe function (#21241) (overlookmotel) - eab13b3 transformer/decorators: Avoid accessor storage name collisions (#21106) (Dunqing) - 07e8a30 transformer/react-refresh: Handle parenthesized variable initializers (#21047) (camc314) ### ⚡ Performance - c3ca6f6 allocator: `StringBuilder::from_strs_array_in` check for 0 length earlier (#21338) (overlookmotel) - c2422bb allocator: `Allocator::alloc_concat_strs_array` check for 0 length earlier (#21337) (overlookmotel) - 04b0fdc allocator: Mark `Allocator::alloc_layout` as `#[inline(always)]` (#21335) (overlookmotel) - 17aee9e allocator: Use `offset_from_unsigned` in `ChunkFooter::as_raw_parts` (#21280) (overlookmotel) - 61adedd minifier: Fix O(n²) perf on very many var decls (#21062) (Gunnlaugur Thor Briem) - addcd02 napi/parser, linter/plugins: Raw transfer deserializer for `Vec`s use shift instead of multiply where possible (#21142) (overlookmotel) - 3068ded napi/parser, linter/plugins: Shift before add when calculating positions in raw transfer deserializer (#21141) (overlookmotel) - eb400b8 napi/parser, linter/plugins: Remove `uint32` buffer view (#21140) (overlookmotel) - 2675085 napi/parser: Lazy deserialization use only `Int32Array` (#21139) (overlookmotel) - 5b35a53 napi/parser: Deserializing tokens use only `int32` array (#21138) (overlookmotel) - f163d10 parser: Tokens raw deserialization use `Int32Array` (#21137) (overlookmotel) - 7a86613 linter/plugins: Use `Int32Array`s for tokens and comments buffers (#21136) (overlookmotel) - 8c51121 napi/parser, linter/plugins: Raw transfer deserialize `Span` fields as `i32`s (#21135) (overlookmotel) - bc1bcdd napi/parser, linter/plugins: Inline trivial raw transfer field deserializers into node object definitions (#21134) (overlookmotel) - c0278ab napi/parser, linter/plugins: Use `Int32Array` in raw transfer deserializer (#21132) (overlookmotel) - 43482c7 linter/plugins: Use `>>` not `>>>` in binary search loops (#21129) (overlookmotel) ### 📚 Documentation - f5e1845 allocator: Upgrade headers in doc comments for `Bump` (#21263) (overlookmotel) - 2870174 allocator: Upper case `SAFETY` in comments (#21253) (overlookmotel) - 01bc269 str: Reformat `Ident` doc comments (#21240) (overlookmotel) - dd47359 allocator: Add doc comments for panics and errors (#21230) (overlookmotel)
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Summary
Fixes #21116 where TypeScript constructor parameter properties emit the wrong property name when the parameter name clashes with a free variable referenced in a class field initializer.
Problem
When targeting pre-ES2022 (or with
transform-class-propertiesenabled), the class properties plugin detects that a constructor parameter name shadows an outer variable referenced in a field initializer, and renames the parameter binding (e.g.x→_x) to preserve the initializer's semantics.convert_constructor_params(TypeScript plugin) ran after this rename and readid.name— which had already been mutated — to produce thethis.X = Xassignment. This caused:to incorrectly emit:
Root Cause
Both plugins share a single traversal pass with interleaved hooks.
enter_class_body(class properties) fires beforeenter_method_definition(TypeScript), so by the timeconvert_constructor_paramsruns,BindingIdentifier.namehas already been mutated byConstructorSymbolRenamer.Fix
Recover the property name from
id.span.source_text(source_text)instead ofid.name. Spans are set by the parser and never mutated by any transformer, so this always returns the original user-written identifier regardless of renames.AI Disclosure
This fix was developed with Claude Code assistance.