fix(minifier): do not remove undefined in var x = undefined (#8526)

This commit is contained in:
Boshen 2025-01-16 02:57:28 +00:00
parent 06f14d526b
commit 92e44cba6b

View file

@ -665,7 +665,9 @@ impl<'a, 'b> PeepholeSubstituteAlternateSyntax {
if decl.kind.is_const() || decl.id.kind.is_destructuring_pattern() {
return;
}
if decl.init.as_ref().is_some_and(|init| ctx.is_expression_undefined(init)) {
if !decl.kind.is_var()
&& decl.init.as_ref().is_some_and(|init| ctx.is_expression_undefined(init))
{
decl.init = None;
self.changed = true;
}
@ -1281,17 +1283,17 @@ mod test {
#[test]
fn test_undefined() {
test("var x = undefined", "var x");
test("let x = undefined", "let x");
test("const x = undefined", "const x = void 0");
test("var x = undefined", "var x = void 0");
test_same("var undefined = 1;function f() {var undefined=2;var x;}");
test_same("function f(undefined) {}");
test_same("try {} catch(undefined) {foo(undefined)}");
test("for (undefined in {}) {}", "for(undefined in {}){}");
test("undefined++;", "undefined++");
test("undefined += undefined;", "undefined+=void 0");
// shadowd
// shadowed
test_same("(function(undefined) { let x = typeof undefined; })()");
// destructuring throw error side effect
test_same("var {} = void 0");
test_same("var [] = void 0");