fix(transformer/object-rest-spread): correct scope id when moving bindings#22419
Merged
graphite-app[bot] merged 1 commit intoMay 14, 2026
Conversation
Contributor
Author
How to use the Graphite Merge QueueAdd either label to this PR to merge it via the merge queue:
You must have a Graphite account in order to use the merge queue. Sign up using this link. An organization admin has enabled the Graphite Merge Queue in this repository. Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue. This stack of pull requests is managed by Graphite. Learn more about stacking. |
Contributor
There was a problem hiding this comment.
Pull request overview
Fixes incorrect semantic scoping updates performed by the ES2018 object rest/spread transformer when it rewrites for-init destructuring patterns into the loop body, ensuring bindings are moved from their actual owning scope.
Changes:
- Use
ctx.scoping().symbol_scope_id(symbol_id)as the source scope when callingmove_binding_by_symbol_id, instead of assuming theforinit scope. - Update
semantic_test262snapshot showing improved pass counts and removal of several previously failing binding-mismatch cases.
Reviewed changes
Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| tasks/coverage/snapshots/semantic_test262.snap | Snapshot update reflecting improved semantic equivalence after transform (fewer mismatches, slightly higher pass rate). |
| crates/oxc_transformer/src/es2018/object_rest_spread.rs | Fix binding moves to use the symbol’s true current scope when relocating bindings into the loop body scope. |
Merging this PR will not alter performance
Comparing 
Footnotes
|
Contributor
Author
Merge activity
|
graphite-app
Bot
changed the base branch from
c/05-14-perf_transformer_object-rest-spread_collect_vec_symbolid_over_vec_ident_
to
graphite-base/22419
camc314
force-pushed
the
c/05-14-fix_transformer_object-rest-spread_correct_scope_id_when_moving_bindings
branch
from
fa3e662 to
f969770
Compare
…dings (#22419) Previously, given: ``` for (var { x, ...rest } of iterable) {} ``` The destructuring pattern appears in the `for` head, but `var` bindings are not owned by that scope - `x` and `rest` are hoisted into the current hoist scope. After transform: ``` for (var _ref of iterable) { var x = _ref.x; var rest = _objectWithoutProperties(_ref, _excluded); } ``` The bindings moved into the loop scope, but since we were passing the `for` loop's scope, `move_binding_by_symbol_id` was a no-op as the var decls were not defined in the `for` loop's scope. This PR get's the declared scope of the symbol and uses it rather than assuming that the var is scoped to the function
graphite-app
Bot
force-pushed
the
c/05-14-fix_transformer_object-rest-spread_correct_scope_id_when_moving_bindings
branch
from
f969770 to
b8fbc1f
Compare
graphite-app
Bot
deleted the
c/05-14-fix_transformer_object-rest-spread_correct_scope_id_when_moving_bindings
branch
overlookmotel
added a commit
that referenced
this pull request
May 15, 2026
### 🚀 Features - bc91a17 codegen: Expose `Codegen::with_source_type` method (#22432) (camc314) ### 🐛 Bug Fixes - 5ac7e79 minifier: Drop unused-var-init pure IIFEs and preserve annotation for downstream (#22349) (Dunqing) - 4ab57eb allocator: Fixed-size allocators use `VirtualAlloc` on Windows (#22124) (overlookmotel) - 66d77eb allocator: Fix segfault on Linux MUSL with fixed-size allocators (#22388) (overlookmotel) - b8fbc1f transformer/object-rest-spread: Correct scope id when moving bindings (#22419) (camc314) - 18edc2c codegen: Keep `Object.defineProperty` property name as plain string in minify (#22400) (Dunqing) - dda33de transformer/explicit-resource-management: Align lexical binding scopes (#22320) (camc314) - 8e79de8 transformer: Preserve for-await statement bodies (#22361) (camc314) - 0cba210 transformer/class: Replace `new.target` in static blocks (#22360) (camc314) - 67ab1c9 transformer/es2018/for-await: Hoist for-await generated bindings (#22355) (camc314) - c3ceb4a transformer/object-rest-spread: Use hoisted scope for `for-of` temp refs (#22347) (camc314) ### ⚡ Performance - 73a9043 allocator/bitset: Avoid temp heap `String` allocation (#22403) (camc314) - 8b2f4f9 transformer/object-rest-spread: Collect `Vec<SymbolId` over `Vec<BindingIdentifier>` (#22418) (camc314) - 83679ea parser: Split TriviaBuilder::handle_token hot/cold paths (#22415) (Boshen) - 2c7d781 codegen: Inline identifier-name accessors (#22411) (Boshen) - 618bc76 diagnostics: Inline `OxcDiagnosticInner` to avoid heap allocation (#22406) (Boshen) - 0b4e158 parser: Reserve cap `2` for sequence expressions vec (#22374) (camc314) - 5f3bdd0 codegen: Add `#[inline]` to `code`, `code_len` (#22373) (camc314) Co-authored-by: overlookmotel <[email protected]>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Previously, given:
The destructuring pattern appears in the
forhead, butvarbindings are not owned by that scope -xandrestare hoisted into the current hoist scope.After transform:
The bindings moved into the loop scope, but since we were passing the
forloop's scope,move_binding_by_symbol_idwas a no-op as the var decls were not defined in theforloop's scope.This PR get's the declared scope of the symbol and uses it rather than assuming that the var is scoped to the function