fix(parser): keep annotation comments leading without preceding newline#22711
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…ne (#22711) ## Summary `@__PURE__` and `@__NO_SIDE_EFFECTS__` annotations semantically mark the *next* token, but the trivia builder's heuristic for "comment sits on the same line as the previous token → trailing of previous" used to apply to them — only `CommentContent::Legal` / `JsdocLegal` were exempted via `should_stay_leading`. This broke `Codegen { minify: true, comments: CommentOptions::default() }` idempotency. In minify mode statements are smashed together with no trailing newlines, so a leading annotation from the source ends up directly after the previous `;`/`}`: ```js // source // pass 1 (minify) foo(); foo();// @__NO_SIDE_EFFECTS__ // @__NO_SIDE_EFFECTS__ function bar(){} function bar() {} ``` Pass 2 then re-parsed `foo();// @…\n` and reclassified the annotation as trailing of the previous `;` (no preceding newline → not leading). The comment was no longer in codegen's leading-annotation map, so emission fell back to the canonical literal `/* @__NO_SIDE_EFFECTS__ */` — diverging from pass 1's verbatim and breaking the idempotency invariant. Extend `should_stay_leading` to also cover `Pure | PureNotApplied | NoSideEffects`. This is consistent with how these annotations are already specified to "annotate the next call/new/function" by tooling (rollup, esbuild, terser). - End-to-end via [monitor-oxc](https://github.com/oxc-project/monitor-oxc)'s `whitespace` runner over the npm-top-3000 corpus: **90 → 0 idempotency failures**. - Covered by 3 new parser unit tests: `no_side_effects_block_comment_after_code_is_attached_to_next_token`, `no_side_effects_line_comment_after_code_is_attached_to_next_token`, `pure_block_comment_after_code_is_attached_to_next_token`. AI disclosure: investigated and implemented with Claude Code, reviewed manually.
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### 🚀 Features - e857b0c napi/minify: Expose legalComments option and result (#20370) (Boshen) - 661132d parser: More friendly error messages for rest assignment target and rest binding element (#22719) (sapphi-red) - ee659b6 transformer/legacy-decorator: Add `strictNullChecks` option for nullable-union design:type (#22266) (Kyle Cannon) ### 🐛 Bug Fixes - e1d064e transformer/class-properties: Reparent lifted private method helpers (#22716) (Cameron) - 4ac0fca minifier: Preserve `0 && (module.exports = { ... })` cjs-module-lexer hint (#22729) (Dunqing) - 40ff611 minifier: Mark peephole loop changed when dropping dead-after-throw statement (#22722) (Dunqing) - 2f7b210 codegen: Emit pife-arrow/function leading comments inside the wrap (#22720) (Dunqing) - e184f74 parser: Improve invalid `import` property access diagnostic (#22693) (camc314) - 7baed9c transformer/private-method: Clear inherited strict flags (#22508) (camc314) - a9ad27e parser: Keep annotation comments leading without preceding newline (#22711) (Dunqing) - 9ea4d64 minifier: Re-evaluate pure/no-side-effects flags after peephole inlining (#22595) (Dunqing) - 07afbb6 minifier: Drop empty-body IIFE wrapper when called with arguments (#22589) (Dunqing) - fa7c463 semantic: Correct TS enum member symbol spans (#22689) (camc314) - 26b9396 semantic: Resolve parameter decorators outside parameter scope (#22623) (camc314) - b284045 parser: Switch to module goal eagerly on `export` (#22684) (Boshen) - dfa931d semantic: Propagate unresolved auto-increment enum value instead of defaulting to 0 (#22646) (Dunqing) - 69a6ba6 transformer/legacy-decorator: Emit Array for ReadonlyArray<T> in decorator metadata (#22265) (Kyle Cannon) - e421ef0 transformer/legacy-decorator: Return runtime binding for design:type (#22640) (Dunqing) - d61e1d7 codegen: Preserve verbatim text of pure/no-side-effects comments (#22525) (Dunqing) - 702b14e minifier: Preserve IIFE structure in DCE-only mode (#22547) (Dunqing) - 917da24 parser: Apply PURE comment through member-access chains (#22566) (Dunqing) - a069b1c codegen: Preserve quotes for cjs-module-lexer equality strings (#22551) (Dunqing) ### ⚡ Performance - 2f623b0 semantic: Skip unresolved checks for re-exports (#22660) (camc314) - 0d9553d semantic: Early-exit `check_object_expression` for objects with <2 properties (#22668) (Dunqing) - d721ad9 semantic: Use direct grandparent lookup for TS type parameters (#22658) (camc314) - 0aff288 semantic: Reorder numeric literal strict mode checks (#22657) (camc314) - 4d5ddb1 semantic: Reorder binding identifier checks (#22656) (camc314) - e32acd8 semantic: Reorder identifier ambient binding check (#22653) (camc314) - 09fe178 semantic: Reorder ident reference strict mode check (#22652) (camc314) - 4b6add2 semantic: Avoid duplicate ident clone for bindings (#22663) (camc314) - 82f9662 parser: Check identifier kind before context flag (#22662) (camc314) - d7cd951 parser: Fast path identifier parsing and inline operator helpers (#22650) (Boshen) - 7b84314 semantic: Use direct byte access for numeric leading-zero check (#22642) (camc314) - 0345a31 semantic: Pre-size class elements hash map (#22618) (camc314) - 04d3065 minifier: Drop per-call buffers in try_fold_concat (#22596) (Dunqing) - 4f289f1 semantic: Resolve_references_for_current_scope without a temp Vec (#22599) (Dunqing) - e862c15 semantic: Avoid heap alloc for var hoist scope ids (#22603) (Dunqing) - 8ff8674 semantic: Early return if `excess` is `0` in `Stats::increase_by` (#22616) (camc314) - 7a4120e semantic: Pre-reserve unresolved_references using Stats::references (#22580) (Dunqing) Co-authored-by: Dunqing <29533304+Dunqing@users.noreply.github.com>
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Summary
@__PURE__and@__NO_SIDE_EFFECTS__annotations semantically mark the next token, but the trivia builder's heuristic for "comment sits on the same line as the previous token → trailing of previous" used to apply to them — onlyCommentContent::Legal/JsdocLegalwere exempted viashould_stay_leading.This broke
Codegen { minify: true, comments: CommentOptions::default() }idempotency. In minify mode statements are smashed together with no trailing newlines, so a leading annotation from the source ends up directly after the previous;/}:Pass 2 then re-parsed
foo();// @…\nand reclassified the annotation as trailing of the previous;(no preceding newline → not leading). The comment was no longer in codegen's leading-annotation map, so emission fell back to the canonical literal/* @__NO_SIDE_EFFECTS__ */— diverging from pass 1's verbatim and breaking the idempotency invariant.Extend
should_stay_leadingto also coverPure | PureNotApplied | NoSideEffects. This is consistent with how these annotations are already specified to "annotate the next call/new/function" by tooling (rollup, esbuild, terser).whitespacerunner over the npm-top-3000 corpus: 90 → 0 idempotency failures.no_side_effects_block_comment_after_code_is_attached_to_next_token,no_side_effects_line_comment_after_code_is_attached_to_next_token,pure_block_comment_after_code_is_attached_to_next_token.AI disclosure: investigated and implemented with Claude Code, reviewed manually.