Merge 8019ac8 into d5c4ebe

Author: kdy1

.changeset/chilled-apples-impress.md

@@ -0,0 +1,6 @@
+---
+swc_core: patch
+swc_ecma_parser: patch
+---
+
+fix(parser): reject invalid object rest assignment targets

crates/swc_ecma_parser/src/parser/pat.rs

@@ -246,15 +246,32 @@ impl<I: Tokens> Parser<I> {
                                     };
 
                                     let element_pat_ty = pat_ty.element();
-                                    let pat = if let PatType::BindingElement = element_pat_ty {
-                                        if let Expr::Ident(i) = *expr {
-                                            i.into()
-                                        } else {
-                                            self.emit_err(span, SyntaxError::DotsWithoutIdentifier);
-                                            Pat::Invalid(Invalid { span })
+                                    let pat = match element_pat_ty {
+                                        PatType::BindingElement => {
+                                            if let Expr::Ident(i) = *expr {
+                                                i.into()
+                                            } else {
+                                                self.emit_err(
+                                                    span,
+                                                    SyntaxError::DotsWithoutIdentifier,
+                                                );
+                                                Pat::Invalid(Invalid { span })
+                                            }
                                         }
-                                    } else {
-                                        self.reparse_expr_as_pat(element_pat_ty, expr)?
+                                        PatType::AssignElement => {
+                                            if !expr.is_valid_simple_assignment_target(
+                                                self.ctx().contains(Context::Strict),
+                                            ) {
+                                                self.emit_err(span, SyntaxError::NotSimpleAssign);
+                                                expr.into()
+                                            } else {
+                                                self.reparse_expr_as_pat(element_pat_ty, expr)?
+                                            }
+                                        }
+                                        _ => unreachable!(
+                                            "object rest element must be binding/assignment \
+                                             element"
+                                        ),
                                     };
                                     if let Pat::Assign(_) = pat {
                                         self.emit_err(span, SyntaxError::TS1048)

crates/swc_ecma_parser/tests/errors/issue-11543/input.js

@@ -0,0 +1 @@
+({...{}} = {});

crates/swc_ecma_parser/tests/errors/issue-11543/input.js.swc-stderr

@@ -0,0 +1,5 @@
+  x Cannot assign to this
+   ,-[$DIR/tests/errors/issue-11543/input.js:1:1]
+ 1 | ({...{}} = {});
+   :   ^^^^^
+   `----