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fix(minifier): do not remove shadowned undefined in return statement (#8371)

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closes #8370
This commit is contained in:
Boshen 2025-01-09 04:03:18 +00:00
parent 814da55f81
commit 82ee77ef19
1 changed files with 11 additions and 11 deletions
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22
crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs
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@ -82,13 +82,8 @@ impl<'a> Traverse<'a> for PeepholeSubstituteAlternateSyntax {
self.try_compress_property_key(&mut prop.key, &mut prop.computed, ctx);
}
fn exit_return_statement(
&mut self,
stmt: &mut ReturnStatement<'a>,
_ctx: &mut TraverseCtx<'a>,
) {
// We may fold `void 1` to `void 0`, so compress it after visiting
self.compress_return_statement(stmt);
fn exit_return_statement(&mut self, stmt: &mut ReturnStatement<'a>, ctx: &mut TraverseCtx<'a>) {
self.compress_return_statement(stmt, ctx);
}
fn exit_variable_declaration(
@ -563,12 +558,12 @@ impl<'a, 'b> PeepholeSubstituteAlternateSyntax {
// `foo == void 0` -> `foo == null`, `foo == undefined` -> `foo == null`
// `foo != void 0` -> `foo == null`, `foo == undefined` -> `foo == null`
if e.operator == BinaryOperator::Inequality || e.operator == BinaryOperator::Equality {
let (left, right) = if e.right.is_undefined() || e.right.is_void_0() {
let (left, right) = if ctx.is_expression_undefined(&e.right) {
(
ctx.ast.move_expression(&mut e.left),
ctx.ast.expression_null_literal(e.right.span()),
)
} else if e.left.is_undefined() || e.left.is_void_0() {
} else if ctx.is_expression_undefined(&e.left) {
(
ctx.ast.move_expression(&mut e.right),
ctx.ast.expression_null_literal(e.left.span()),
@ -587,8 +582,12 @@ impl<'a, 'b> PeepholeSubstituteAlternateSyntax {
///
/// `return undefined` -> `return`
/// `return void 0` -> `return`
fn compress_return_statement(&mut self, stmt: &mut ReturnStatement<'a>) {
if stmt.argument.as_ref().is_some_and(|expr| expr.is_undefined() || expr.is_void_0()) {
fn compress_return_statement(
&mut self,
stmt: &mut ReturnStatement<'a>,
ctx: &mut TraverseCtx<'a>,
) {
if stmt.argument.as_ref().is_some_and(|expr| Ctx(ctx).is_expression_undefined(expr)) {
stmt.argument = None;
self.changed = true;
}
@ -1140,6 +1139,7 @@ mod test {
test("function f(){return undefined;}", "function f(){return}");
// Here we handle the block in dce.
test("function f(){if(a()){return undefined;}}", "function f(){if(a()){return}}");
test_same("function a(undefined) { return undefined; }");
}
#[test]