validate parentheses in the left-hand side of assignment expressions (#10576)

* invalid left-hand assignments based on parenthesis

* validate against nested ParenthesizedExpressions

packages/babel-parser/src/parser/expression.js

@@ -41,12 +41,6 @@ import {
   SCOPE_PROGRAM,
 } from "../util/scopeflags";
 
-const unwrapParenthesizedExpression = node => {
-  return node.type === "ParenthesizedExpression"
-    ? unwrapParenthesizedExpression(node.expression)
-    : node;
-};
-
 export default class ExpressionParser extends LValParser {
   // Forward-declaration: defined in statement.js
   +parseBlock: (
@@ -213,26 +207,6 @@ export default class ExpressionParser extends LValParser {
 
       this.checkLVal(left, undefined, undefined, "assignment expression");
 
-      const maybePattern = unwrapParenthesizedExpression(left);
-
-      let patternErrorMsg;
-      if (maybePattern.type === "ObjectPattern") {
-        patternErrorMsg = "`({a}) = 0` use `({a} = 0)`";
-      } else if (maybePattern.type === "ArrayPattern") {
-        patternErrorMsg = "`([a]) = 0` use `([a] = 0)`";
-      }
-
-      if (
-        patternErrorMsg &&
-        ((left.extra && left.extra.parenthesized) ||
-          left.type === "ParenthesizedExpression")
-      ) {
-        this.raise(
-          maybePattern.start,
-          `You're trying to assign to a parenthesized expression, eg. instead of ${patternErrorMsg}`,
-        );
-      }
-
       this.next();
       node.right = this.parseMaybeAssign(noIn);
       return this.finishNode(node, "AssignmentExpression");

packages/babel-parser/src/parser/lval.js

@@ -22,6 +22,12 @@ import {
 import { NodeUtils } from "./node";
 import { type BindingTypes, BIND_NONE } from "../util/scopeflags";
 
+const unwrapParenthesizedExpression = (node: Node) => {
+  return node.type === "ParenthesizedExpression"
+    ? unwrapParenthesizedExpression(node.expression)
+    : node;
+};
+
 export default class LValParser extends NodeUtils {
   // Forward-declaration: defined in expression.js
   +parseIdentifier: (liberal?: boolean) => Identifier;
@@ -49,6 +55,20 @@ export default class LValParser extends NodeUtils {
     contextDescription: string,
   ): Node {
     if (node) {
+      if (
+        (this.options.createParenthesizedExpressions &&
+          node.type === "ParenthesizedExpression") ||
+        node.extra?.parenthesized
+      ) {
+        const parenthesized = unwrapParenthesizedExpression(node);
+        if (
+          parenthesized.type !== "Identifier" &&
+          parenthesized.type !== "MemberExpression"
+        ) {
+          this.raise(node.start, "Invalid parenthesized assignment pattern");
+        }
+      }
+
       switch (node.type) {
         case "Identifier":
         case "ObjectPattern":