fix: new.target with shadowed class name (#14611)

packages/babel-plugin-transform-new-target/src/index.ts

@@ -47,9 +47,6 @@ export default declare(api => {
             path.replaceWith(scope.buildUndefinedNode());
             return;
           }
-          if (!node.id) {
-            node.id = scope.generateUidIdentifier("target");
-          }
 
           const constructor = t.memberExpression(
             t.thisExpression(),
@@ -61,6 +58,23 @@ export default declare(api => {
             return;
           }
 
+          if (!node.id) {
+            node.id = scope.generateUidIdentifier("target");
+          } else {
+            // packages/babel-helper-create-class-features-plugin/src/fields.ts#L192 unshadow
+            let scope = path.scope;
+            const name = node.id.name;
+            while (scope !== func.parentPath.scope) {
+              if (
+                scope.hasOwnBinding(name) &&
+                !scope.bindingIdentifierEquals(name, node.id)
+              ) {
+                scope.rename(name);
+              }
+              scope = scope.parent;
+            }
+          }
+
           path.replaceWith(
             t.conditionalExpression(
               t.binaryExpression(

packages/babel-plugin-transform-new-target/test/fixtures/general/class-properties-loose/output.js

@@ -11,23 +11,23 @@ class Foo {
       _newtarget;
     };
 
-    this.Bar = (_class = class _target2 {
+    this.Bar = (_class = class {
       constructor() {
         this.q = this.constructor;
       } // should not replace
 
 
-    }, _class.p = void 0, _class.p1 = class _target3 {
+    }, _class.p = void 0, _class.p1 = class {
       constructor() {
         this.constructor;
       }
 
-    }, _class.p2 = new function _target4() {
-      this instanceof _target4 ? this.constructor : void 0;
+    }, _class.p2 = new function _target2() {
+      this instanceof _target2 ? this.constructor : void 0;
     }(), _class.p3 = function () {
       void 0;
-    }, _class.p4 = function _target5() {
-      this instanceof _target5 ? this.constructor : void 0;
+    }, _class.p4 = function _target3() {
+      this instanceof _target3 ? this.constructor : void 0;
     }, _class);
   }
 

packages/babel-plugin-transform-new-target/test/fixtures/general/class-properties/output.js

@@ -9,23 +9,23 @@ class Foo {
     babelHelpers.defineProperty(this, "test2", function () {
       _newtarget;
     });
-    this.Bar = (_class = class _target2 {
+    this.Bar = (_class = class {
       constructor() {
         babelHelpers.defineProperty(this, "q", this.constructor);
       } // should not replace
 
 
-    }, babelHelpers.defineProperty(_class, "p", void 0), babelHelpers.defineProperty(_class, "p1", class _target3 {
+    }, babelHelpers.defineProperty(_class, "p", void 0), babelHelpers.defineProperty(_class, "p1", class {
       constructor() {
         this.constructor;
       }
 
-    }), babelHelpers.defineProperty(_class, "p2", new function _target4() {
-      this instanceof _target4 ? this.constructor : void 0;
+    }), babelHelpers.defineProperty(_class, "p2", new function _target2() {
+      this instanceof _target2 ? this.constructor : void 0;
     }()), babelHelpers.defineProperty(_class, "p3", function () {
       void 0;
-    }), babelHelpers.defineProperty(_class, "p4", function _target5() {
-      this instanceof _target5 ? this.constructor : void 0;
+    }), babelHelpers.defineProperty(_class, "p4", function _target3() {
+      this instanceof _target3 ? this.constructor : void 0;
     }), _class);
   }
 

packages/babel-plugin-transform-new-target/test/fixtures/general/function-duplicate-name/input.js

@@ -0,0 +1,13 @@
+function Foo() {
+  function Foo() {
+    var Foo = new.target;
+  }
+
+  Foo.prototype.test = function() {
+    var Foo = new.target;
+  };
+}
+
+var Bar = function() {
+  var Bar = new.target;
+};

packages/babel-plugin-transform-new-target/test/fixtures/general/function-duplicate-name/output.js

@@ -0,0 +1,13 @@
+function Foo() {
+  function Foo() {
+    var _Foo = this instanceof Foo ? this.constructor : void 0;
+  }
+
+  Foo.prototype.test = function _target() {
+    var Foo = this instanceof _target ? this.constructor : void 0;
+  };
+}
+
+var Bar = function _target2() {
+  var Bar = this instanceof _target2 ? this.constructor : void 0;
+};