Skip to content

fix(transformer): remove unnecessary trailing expression in object rest spread assignment #19259

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
graphite-app merged 1 commit into from
Feb 11, 2026
Merged

fix(transformer): remove unnecessary trailing expression in object rest spread assignment #19259

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 9 additions & 4 deletions crates/oxc_transformer/src/es2018/object_rest_spread.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -275,10 +275,15 @@ impl<'a> ObjectRestSpread<'a> {
}
}

// Insert final read `_foo`.
// TODO: remove this if the assignment is not a read reference.
// e.g. remove for `({ a2, ...b2 } = c2)`, keep `(x, ({ a2, ...b2 } = c2)`.
expressions.push(reference_builder.create_read_expression(ctx));
// Insert final read `_foo` only if the expression result is consumed.
// e.g. remove for `({ a2, ...b2 } = c2)`, keep for `(x, ({ a2, ...b2 } = c2))`.
let is_expression_statement = ctx
.ancestors()
.find(|a| !matches!(a, Ancestor::ParenthesizedExpressionExpression(_)))
.is_some_and(|a| matches!(a, Ancestor::ExpressionStatementExpression(_)));
if !is_expression_statement {
expressions.push(reference_builder.create_read_expression(ctx));
}

*expr = ctx.ast.expression_sequence(assign_expr.span, expressions);
}
Expand Down
2 changes: 1 addition & 1 deletion ...in-transform-object-rest-spread/test/fixtures/object-rest/assignment-expression/output.js
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
({a1} = c1);
var _c;
_c = c2, {a2} = _c, b2 = babelHelpers.objectWithoutProperties(_c, ["a2"]), _c;
_c = c2, {a2} = _c, b2 = babelHelpers.objectWithoutProperties(_c, ["a2"]);
var _c2;
console.log((_c2 = c3, {a3} = _c2, b3 = babelHelpers.objectWithoutProperties(_c2, ["a3"]), _c2));
2 changes: 1 addition & 1 deletion ...l-plugin-transform-object-rest-spread/test/fixtures/object-rest/impure-computed/output.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ var _$z;
_$z = {
2: "two",
z: "zee"
}, {[key]: y, z} = _$z, x = babelHelpers.objectWithoutProperties(_$z, [key, "z"].map(babelHelpers.toPropertyKey)), _$z;
}, {[key]: y, z} = _$z, x = babelHelpers.objectWithoutProperties(_$z, [key, "z"].map(babelHelpers.toPropertyKey));
expect(y).toBe("two");
expect(x).toEqual({});
expect(z).toBe("zee");
2 changes: 1 addition & 1 deletion ...-spread/test/fixtures/object-rest/template-literal-allLiterals-true-no-hoisting/output.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,5 +2,5 @@ const example = () => {
const input = {};
const foo = "foo";
var _input, _ref = `${foo}_bar`;
_input = input, {[_ref]: country} = _input, rest = babelHelpers.objectWithoutProperties(_input, [_ref].map(babelHelpers.toPropertyKey)), _input;
_input = input, {[_ref]: country} = _input, rest = babelHelpers.objectWithoutProperties(_input, [_ref].map(babelHelpers.toPropertyKey));
};
102 changes: 3 additions & 99 deletions tasks/transform_conformance/snapshots/babel.snap.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -968,63 +968,7 @@ x Output mismatch

# babel-plugin-transform-object-rest-spread (27/40)
* object-rest/for-x/input.js
Bindings mismatch:
after transform: ScopeId(0): ["_excluded", "_excluded2", "_excluded3", "_ref", "a", "b"]
rebuilt : ScopeId(0): ["_excluded", "_excluded2", "_excluded3", "_ref", "_ref2", "_ref3", "a"]
Bindings mismatch:
after transform: ScopeId(2): []
rebuilt : ScopeId(2): ["a", "b"]
Bindings mismatch:
after transform: ScopeId(3): ["_ref2"]
rebuilt : ScopeId(3): []
Bindings mismatch:
after transform: ScopeId(4): ["_ref3"]
rebuilt : ScopeId(4): []
Bindings mismatch:
after transform: ScopeId(5): []
rebuilt : ScopeId(5): ["_ref4", "_ref5"]
Bindings mismatch:
after transform: ScopeId(6): ["_ref4"]
rebuilt : ScopeId(6): []
Bindings mismatch:
after transform: ScopeId(7): ["_ref5"]
rebuilt : ScopeId(7): []
Symbol flags mismatch for "a":
after transform: SymbolId(0): SymbolFlags(BlockScopedVariable)
rebuilt : SymbolId(8): SymbolFlags(Function)
Symbol span mismatch for "a":
after transform: SymbolId(0): Span { start: 27, end: 28 }
rebuilt : SymbolId(8): Span { start: 86, end: 87 }
Symbol scope ID mismatch for "a":
after transform: SymbolId(0): ScopeId(2)
rebuilt : SymbolId(8): ScopeId(0)
Symbol redeclarations mismatch for "a":
after transform: SymbolId(0): [Span { start: 27, end: 28 }, Span { start: 86, end: 87 }, Span { start: 189, end: 190 }, Span { start: 274, end: 275 }]
rebuilt : SymbolId(8): [Span { start: 86, end: 87 }, Span { start: 189, end: 190 }, Span { start: 274, end: 275 }]
Symbol reference IDs mismatch for "b":
after transform: SymbolId(1): [ReferenceId(1), ReferenceId(3)]
rebuilt : SymbolId(5): []
Symbol scope ID mismatch for "_ref2":
after transform: SymbolId(4): ScopeId(3)
rebuilt : SymbolId(6): ScopeId(0)
Symbol scope ID mismatch for "_ref3":
after transform: SymbolId(5): ScopeId(4)
rebuilt : SymbolId(7): ScopeId(0)
Symbol scope ID mismatch for "_ref4":
after transform: SymbolId(7): ScopeId(6)
rebuilt : SymbolId(9): ScopeId(5)
Symbol scope ID mismatch for "_ref5":
after transform: SymbolId(8): ScopeId(7)
rebuilt : SymbolId(10): ScopeId(5)
Reference symbol mismatch for "b":
after transform: SymbolId(1) "b"
rebuilt : <None>
Reference symbol mismatch for "b":
after transform: SymbolId(1) "b"
rebuilt : <None>
Unresolved references mismatch:
after transform: ["babelHelpers"]
rebuilt : ["b", "babelHelpers"]
x Output mismatch

* object-rest/for-x-array-pattern/input.js
x Output mismatch
Expand All @@ -1036,21 +980,7 @@ x Output mismatch
x Output mismatch

* object-rest/for-x-completion-record/input.js
Bindings mismatch:
after transform: ScopeId(0): ["_excluded"]
rebuilt : ScopeId(0): ["_excluded", "_ref", "_ref2"]
Bindings mismatch:
after transform: ScopeId(1): ["_ref"]
rebuilt : ScopeId(1): []
Bindings mismatch:
after transform: ScopeId(2): ["_ref2"]
rebuilt : ScopeId(2): []
Symbol scope ID mismatch for "_ref":
after transform: SymbolId(0): ScopeId(1)
rebuilt : SymbolId(1): ScopeId(0)
Symbol scope ID mismatch for "_ref2":
after transform: SymbolId(1): ScopeId(2)
rebuilt : SymbolId(2): ScopeId(0)
x Output mismatch

* object-rest/for-x-declaration-shadowed-block-scoped-bindings/input.js
x Output mismatch
Expand Down Expand Up @@ -1146,33 +1076,7 @@ after transform: ["b", "babelHelpers", "f", "q"]
rebuilt : ["R", "Y", "b", "babelHelpers", "f", "q"]

* object-rest/symbol/input.js
Bindings mismatch:
after transform: ScopeId(0): ["_Symbol$for", "_Symbol$for2", "_Symbol$for3", "_ref", "_ref2", "_ref3", "foo", "rest"]
rebuilt : ScopeId(0): ["_Symbol$for", "_Symbol$for2", "_ref", "_ref2", "foo", "rest"]
Reference symbol mismatch for "_ref3":
after transform: SymbolId(6) "_ref3"
rebuilt : <None>
Reference symbol mismatch for "_Symbol$for3":
after transform: SymbolId(7) "_Symbol$for3"
rebuilt : <None>
Reference symbol mismatch for "_ref3":
after transform: SymbolId(6) "_ref3"
rebuilt : <None>
Reference symbol mismatch for "_ref3":
after transform: SymbolId(6) "_ref3"
rebuilt : <None>
Reference symbol mismatch for "_Symbol$for3":
after transform: SymbolId(7) "_Symbol$for3"
rebuilt : <None>
Reference symbol mismatch for "_ref3":
after transform: SymbolId(6) "_ref3"
rebuilt : <None>
Unresolved references mismatch:
after transform: ["Symbol", "babelHelpers"]
rebuilt : ["Symbol", "_Symbol$for3", "_ref3", "babelHelpers"]
Unresolved reference IDs mismatch for "Symbol":
after transform: [ReferenceId(0), ReferenceId(1), ReferenceId(4)]
rebuilt : [ReferenceId(0), ReferenceId(7)]
x Output mismatch

* regression/gh-17274/input.js
x Output mismatch
Expand Down
2 changes: 1 addition & 1 deletion ...in-transform-object-rest-spread/test/fixtures/object-rest/assignment-expression/output.js
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
({a1} = c1);
var _c;
_c = c2, {a2} = _c, b2 = babelHelpers.objectWithoutProperties(_c, ["a2"]), _c;
_c = c2, {a2} = _c, b2 = babelHelpers.objectWithoutProperties(_c, ["a2"]);
var _c2;
a0, _c2 = c2, {a2} = _c2, b2 = babelHelpers.objectWithoutProperties(_c2, ["a2"]), _c2;
var _c3;
Expand Down
Loading