fix(es/minifier): Preserve __proto__ shorthand property behavior

.changeset/dry-queens-clean.md

@@ -0,0 +1,6 @@
+---
+swc_ecma_minifier: patch
+swc_core: patch
+---
+
+fix(es/minifier): Preserve `__proto__` shorthand property behavior

crates/swc_ecma_minifier/src/compress/optimize/util.rs

@@ -469,8 +469,9 @@ impl VisitMut for Finalizer<'_> {
 
         if let Prop::Shorthand(i) = n {
             if let Some(expr) = self.lits.get(&i.to_id()) {
+                let key = prop_name_from_ident(i.take());
                 *n = Prop::KeyValue(KeyValueProp {
-                    key: i.take().into(),
+                    key,
                     value: expr.clone(),
                 });
                 self.changed = true;
@@ -566,10 +567,8 @@ impl VisitMut for NormalMultiReplacer<'_> {
                 debug!("multi-replacer: Replaced `{}` as shorthand", i);
                 self.changed = true;
 
-                *p = Prop::KeyValue(KeyValueProp {
-                    key: PropName::Ident(IdentName::new(i.sym.clone(), i.span)),
-                    value,
-                });
+                let key = prop_name_from_ident(i.take());
+                *p = Prop::KeyValue(KeyValueProp { key, value });
             }
         }
     }
@@ -642,10 +641,8 @@ impl VisitMut for ExprReplacer {
                 } else {
                     unreachable!("`{}` is already taken", i)
                 };
-                *p = Prop::KeyValue(KeyValueProp {
-                    key: PropName::Ident(i.clone().into()),
-                    value,
-                });
+                let key = prop_name_from_ident(i.take());
+                *p = Prop::KeyValue(KeyValueProp { key, value });
             }
         }
     }
@@ -820,3 +817,21 @@ pub fn get_ids_of_pat(pat: &Pat) -> Vec<Id> {
     append(pat, &mut idents);
     idents
 }
+
+/// Creates a PropName for a shorthand property, handling the special case of
+/// `__proto__`. When the property name is `__proto__`, it must be converted to
+/// a computed property to preserve JavaScript semantics.
+fn prop_name_from_ident(ident: Ident) -> PropName {
+    if ident.sym == "__proto__" {
+        PropName::Computed(ComputedPropName {
+            span: ident.span,
+            expr: Box::new(Expr::Lit(Lit::Str(Str {
+                span: ident.span,
+                value: ident.sym.clone(),
+                raw: None,
+            }))),
+        })
+    } else {
+        ident.into()
+    }
+}

crates/swc_ecma_minifier/tests/fixture/issues/11105/input.js

@@ -0,0 +1 @@
+var __proto__ = []; console.log({ __proto__ } instanceof Array) // false

crates/swc_ecma_minifier/tests/fixture/issues/11105/output.js

@@ -0,0 +1,3 @@
+console.log(({
+    ["__proto__"]: []
+}) instanceof Array); // false