Fix duplicated assertThisInitialized calls in constructors (#9458)

packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/derived-multiple-supers/output.js

@@ -12,13 +12,13 @@ function (_Bar) {
 
     if (condition) {
       _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
-      Object.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this))), _bar, {
+      Object.defineProperty(babelHelpers.assertThisInitialized(_this), _bar, {
         writable: true,
         value: "foo"
       });
     } else {
       _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
-      Object.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this))), _bar, {
+      Object.defineProperty(babelHelpers.assertThisInitialized(_this), _bar, {
         writable: true,
         value: "foo"
       });

packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/derived/output.js

@@ -22,7 +22,7 @@ function (_Foo) {
 
     babelHelpers.classCallCheck(this, Bar);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Bar).call(this, ...args));
-    Object.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), _prop2, {
+    Object.defineProperty(babelHelpers.assertThisInitialized(_this), _prop2, {
       writable: true,
       value: "bar"
     });

packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/foobar/output.js

@@ -10,7 +10,7 @@ function (_Parent) {
 
     babelHelpers.classCallCheck(this, Child);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Child).call(this));
-    Object.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), _scopedFunctionWithThis, {
+    Object.defineProperty(babelHelpers.assertThisInitialized(_this), _scopedFunctionWithThis, {
       writable: true,
       value: function value() {
         _this.name = {};

packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/super-expression/output.js

@@ -9,7 +9,7 @@ function (_Bar) {
     var _temp, _this;
 
     babelHelpers.classCallCheck(this, Foo);
-    foo((_temp = _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this)), Object.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), _bar, {
+    foo((_temp = _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this)), Object.defineProperty(babelHelpers.assertThisInitialized(_this), _bar, {
       writable: true,
       value: "foo"
     }), _temp));

packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/super-statement/output.js

@@ -10,7 +10,7 @@ function (_Bar) {
 
     babelHelpers.classCallCheck(this, Foo);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
-    Object.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), _bar, {
+    Object.defineProperty(babelHelpers.assertThisInitialized(_this), _bar, {
       writable: true,
       value: "foo"
     });

packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived-multiple-supers/output.js

@@ -13,14 +13,14 @@ function (_Bar) {
     if (condition) {
       _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
 
-      _bar.set(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this))), {
+      _bar.set(babelHelpers.assertThisInitialized(_this), {
         writable: true,
         value: "foo"
       });
     } else {
       _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
 
-      _bar.set(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this))), {
+      _bar.set(babelHelpers.assertThisInitialized(_this), {
         writable: true,
         value: "foo"
       });

packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived/output.js

@@ -24,7 +24,7 @@ function (_Foo) {
     babelHelpers.classCallCheck(this, Bar);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Bar).call(this, ...args));
 
-    _prop2.set(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), {
+    _prop2.set(babelHelpers.assertThisInitialized(_this), {
       writable: true,
       value: "bar"
     });

packages/babel-plugin-proposal-class-properties/test/fixtures/private/foobar/output.js

@@ -11,7 +11,7 @@ function (_Parent) {
     babelHelpers.classCallCheck(this, Child);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Child).call(this));
 
-    _scopedFunctionWithThis.set(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), {
+    _scopedFunctionWithThis.set(babelHelpers.assertThisInitialized(_this), {
       writable: true,
       value: () => {
         _this.name = {};

packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-call/output.js

@@ -29,7 +29,7 @@ function (_A) {
     babelHelpers.classCallCheck(this, B);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(B).call(this, ...args));
 
-    _foo.set(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), {
+    _foo.set(babelHelpers.assertThisInitialized(_this), {
       writable: true,
       value: babelHelpers.get(babelHelpers.getPrototypeOf(B.prototype), "foo", babelHelpers.assertThisInitialized(_this)).call(babelHelpers.assertThisInitialized(_this))
     });

packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-expression/output.js

@@ -9,7 +9,7 @@ function (_Bar) {
     var _temp, _this;
 
     babelHelpers.classCallCheck(this, Foo);
-    foo((_temp = _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this)), _bar.set(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), {
+    foo((_temp = _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this)), _bar.set(babelHelpers.assertThisInitialized(_this), {
       writable: true,
       value: "foo"
     }), _temp));

packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-statement/output.js

@@ -11,7 +11,7 @@ function (_Bar) {
     babelHelpers.classCallCheck(this, Foo);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
 
-    _bar.set(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), {
+    _bar.set(babelHelpers.assertThisInitialized(_this), {
       writable: true,
       value: "foo"
     });

packages/babel-plugin-proposal-class-properties/test/fixtures/public/derived-multiple-supers/output.js

@@ -12,10 +12,10 @@ function (_Bar) {
 
     if (condition) {
       _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
-      babelHelpers.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this))), "bar", "foo");
+      babelHelpers.defineProperty(babelHelpers.assertThisInitialized(_this), "bar", "foo");
     } else {
       _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
-      babelHelpers.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this))), "bar", "foo");
+      babelHelpers.defineProperty(babelHelpers.assertThisInitialized(_this), "bar", "foo");
     }
 
     return babelHelpers.possibleConstructorReturn(_this);

packages/babel-plugin-proposal-class-properties/test/fixtures/public/derived/output.js

@@ -10,7 +10,7 @@ function (_Bar) {
 
     babelHelpers.classCallCheck(this, Foo);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this, ...args));
-    babelHelpers.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), "bar", "foo");
+    babelHelpers.defineProperty(babelHelpers.assertThisInitialized(_this), "bar", "foo");
     return _this;
   }
 

packages/babel-plugin-proposal-class-properties/test/fixtures/public/foobar/output.js

@@ -10,7 +10,7 @@ function (_Parent) {
 
     babelHelpers.classCallCheck(this, Child);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Child).call(this));
-    babelHelpers.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), "scopedFunctionWithThis", function () {
+    babelHelpers.defineProperty(babelHelpers.assertThisInitialized(_this), "scopedFunctionWithThis", function () {
       _this.name = {};
     });
     return _this;

packages/babel-plugin-proposal-class-properties/test/fixtures/public/super-call/output.js

@@ -28,7 +28,7 @@ function (_A) {
 
     babelHelpers.classCallCheck(this, B);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(B).call(this, ...args));
-    babelHelpers.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), "foo", babelHelpers.get(babelHelpers.getPrototypeOf(B.prototype), "foo", babelHelpers.assertThisInitialized(_this)).call(babelHelpers.assertThisInitialized(_this)));
+    babelHelpers.defineProperty(babelHelpers.assertThisInitialized(_this), "foo", babelHelpers.get(babelHelpers.getPrototypeOf(B.prototype), "foo", babelHelpers.assertThisInitialized(_this)).call(babelHelpers.assertThisInitialized(_this)));
     return _this;
   }
 

packages/babel-plugin-proposal-class-properties/test/fixtures/public/super-expression/output.js

@@ -9,7 +9,7 @@ function (_Bar) {
     var _temp, _this;
 
     babelHelpers.classCallCheck(this, Foo);
-    foo((_temp = _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this)), babelHelpers.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), "bar", "foo"), _temp));
+    foo((_temp = _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this)), babelHelpers.defineProperty(babelHelpers.assertThisInitialized(_this), "bar", "foo"), _temp));
     return _this;
   }
 

packages/babel-plugin-proposal-class-properties/test/fixtures/public/super-statement/output.js

@@ -10,7 +10,7 @@ function (_Bar) {
 
     babelHelpers.classCallCheck(this, Foo);
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
-    babelHelpers.defineProperty(babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this)), "bar", "foo");
+    babelHelpers.defineProperty(babelHelpers.assertThisInitialized(_this), "bar", "foo");
     return _this;
   }
 

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/6154/output.js

@@ -2,12 +2,12 @@ function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterat
 
 function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }
 
+function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
+
 function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
-function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
-
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
@@ -43,7 +43,7 @@ var Test = function Test() {
 
       _this = _possibleConstructorReturn(this, (_getPrototypeOf2 = _getPrototypeOf(Other)).call.apply(_getPrototypeOf2, [this].concat(args)));
 
-      _defineProperty(_assertThisInitialized(_assertThisInitialized(_this)), "a", function () {
+      _defineProperty(_assertThisInitialized(_this), "a", function () {
         return _get(_getPrototypeOf(Other.prototype), "test", _assertThisInitialized(_this));
       });
 

packages/babel-plugin-transform-classes/src/transformClass.js

@@ -32,25 +32,6 @@ const verifyConstructorVisitor = traverse.visitors.merge([
         );
       }
     },
-
-    ThisExpression(path, state) {
-      if (!state.isDerived) return;
-
-      const { node, parentPath } = path;
-      if (parentPath.isMemberExpression({ object: node })) {
-        // In cases like this.foo or this[foo], there is no need to add
-        // assertThisInitialized, since they already throw if this is
-        // undefined.
-        return;
-      }
-
-      const assertion = t.callExpression(
-        state.file.addHelper("assertThisInitialized"),
-        [node],
-      );
-      path.replaceWith(assertion);
-      path.skip();
-    },
   },
 ]);
 
@@ -84,7 +65,6 @@ export default function transformClass(
     instancePropRefs: {},
     staticPropBody: [],
     body: [],
-    bareSupers: new Set(),
     superThises: [],
     pushedConstructor: false,
     pushedInherits: false,
@@ -217,34 +197,22 @@ export default function transformClass(
 
         replaceSupers.replace();
 
-        // TODO this needs to be cleaned up. But, one step at a time.
+        const superReturns = [];
-        const state = {
-          returns: [],
-          bareSupers: new Set(),
-        };
         path.traverse(
           traverse.visitors.merge([
             environmentVisitor,
             {
-              ReturnStatement(path, state) {
+              ReturnStatement(path) {
                 if (!path.getFunctionParent().isArrowFunctionExpression()) {
-                  state.returns.push(path);
+                  superReturns.push(path);
-                }
-              },
-
-              Super(path, state) {
-                const { node, parentPath } = path;
-                if (parentPath.isCallExpression({ callee: node })) {
-                  state.bareSupers.add(parentPath);
                 }
               },
             },
           ]),
-          state,
         );
 
         if (isConstructor) {
-          pushConstructor(state, node, path);
+          pushConstructor(superReturns, node, path);
         } else {
           pushMethod(node, path);
         }
@@ -378,15 +346,43 @@ export default function transformClass(
 
     path.traverse(findThisesVisitor);
 
-    let guaranteedSuperBeforeFinish = !!classState.bareSupers.size;
-
     let thisRef = function() {
       const ref = path.scope.generateDeclaredUidIdentifier("this");
       thisRef = () => t.cloneNode(ref);
       return ref;
     };
 
-    for (const bareSuper of classState.bareSupers) {
+    for (const thisPath of classState.superThises) {
+      const { node, parentPath } = thisPath;
+      if (parentPath.isMemberExpression({ object: node })) {
+        thisPath.replaceWith(thisRef());
+        continue;
+      }
+      thisPath.replaceWith(
+        t.callExpression(classState.file.addHelper("assertThisInitialized"), [
+          thisRef(),
+        ]),
+      );
+    }
+
+    const bareSupers = new Set();
+    path.traverse(
+      traverse.visitors.merge([
+        environmentVisitor,
+        {
+          Super(path) {
+            const { node, parentPath } = path;
+            if (parentPath.isCallExpression({ callee: node })) {
+              bareSupers.add(parentPath);
+            }
+          },
+        },
+      ]),
+    );
+
+    let guaranteedSuperBeforeFinish = !!bareSupers.size;
+
+    for (const bareSuper of bareSupers) {
       wrapSuperCall(bareSuper, classState.superName, thisRef, body);
 
       if (guaranteedSuperBeforeFinish) {
@@ -408,19 +404,6 @@ export default function transformClass(
       }
     }
 
-    for (const thisPath of classState.superThises) {
-      const { node, parentPath } = thisPath;
-      if (parentPath.isMemberExpression({ object: node })) {
-        thisPath.replaceWith(thisRef());
-        continue;
-      }
-      thisPath.replaceWith(
-        t.callExpression(classState.file.addHelper("assertThisInitialized"), [
-          thisRef(),
-        ]),
-      );
-    }
-
     let wrapReturn;
 
     if (classState.isLoose) {
@@ -535,7 +518,7 @@ export default function transformClass(
    * Replace the constructor body of our class.
    */
   function pushConstructor(
-    replaceSupers,
+    superReturns,
     method: { type: "ClassMethod" },
     path: NodePath,
   ) {
@@ -548,8 +531,7 @@ export default function transformClass(
       userConstructorPath: path,
       userConstructor: method,
       hasConstructor: true,
-      bareSupers: replaceSupers.bareSupers,
+      superReturns,
-      superReturns: replaceSupers.returns,
     });
 
     const { construct } = classState;

packages/babel-plugin-transform-classes/test/fixtures/regression/3028/output.js

@@ -21,7 +21,7 @@ function (_b) {
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(a1).call(this));
 
     _this.x = function () {
-      return babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this));
+      return babelHelpers.assertThisInitialized(_this);
     };
 
     return _this;
@@ -42,7 +42,7 @@ function (_b2) {
     _this2 = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(a2).call(this));
 
     _this2.x = function () {
-      return babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this2));
+      return babelHelpers.assertThisInitialized(_this2);
     };
 
     return _this2;

packages/babel-plugin-transform-classes/test/fixtures/spec/this-not-allowed-before-super-in-derived-classes-2/output.js

@@ -9,7 +9,7 @@ function (_Bar) {
     var _this;
 
     babelHelpers.classCallCheck(this, Foo);
-    return _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this, babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this))));
+    return _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this, babelHelpers.assertThisInitialized(_this)));
   }
 
   return Foo;

packages/babel-plugin-transform-classes/test/fixtures/spec/this-not-allowed-before-super-in-derived-classes-3/output.js

@@ -10,7 +10,7 @@ function (_Bar) {
 
     babelHelpers.classCallCheck(this, Foo);
 
-    var fn = () => babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this));
+    var fn = () => babelHelpers.assertThisInitialized(_this);
 
     fn();
     return _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));

packages/babel-plugin-transform-classes/test/fixtures/spec/this-not-allowed-before-super-in-derived-classes-4/output.js

@@ -10,7 +10,7 @@ function (_Bar) {
 
     babelHelpers.classCallCheck(this, Foo);
 
-    var fn = () => babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this));
+    var fn = () => babelHelpers.assertThisInitialized(_this);
 
     _this = babelHelpers.possibleConstructorReturn(this, babelHelpers.getPrototypeOf(Foo).call(this));
     fn();

packages/babel-plugin-transform-classes/test/fixtures/spec/this-not-allowed-before-super-in-derived-classes-5/output.js

@@ -9,7 +9,7 @@ function (_Bar) {
     var _this;
 
     babelHelpers.classCallCheck(this, Foo);
-    Foo[babelHelpers.assertThisInitialized(babelHelpers.assertThisInitialized(_this))];
+    Foo[babelHelpers.assertThisInitialized(_this)];
     return babelHelpers.possibleConstructorReturn(_this);
   }
 

packages/babel-plugin-transform-parameters/test/fixtures/regression/6057-expanded/output.js

@@ -21,12 +21,12 @@ function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) ===
 
 function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }
 
+function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
+
 function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
-function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
-
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 
 var App =
@@ -47,7 +47,7 @@ function (_Component) {
 
     _this = _possibleConstructorReturn(this, (_getPrototypeOf2 = _getPrototypeOf(App)).call.apply(_getPrototypeOf2, [this].concat(args)));
 
-    _defineProperty(_assertThisInitialized(_assertThisInitialized(_this)), "exportType", '');
+    _defineProperty(_assertThisInitialized(_this), "exportType", '');
 
     return _this;
   }