Fix default class super inheritance (#7732)

Fixes #7683.

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

@@ -382,7 +382,6 @@ export default function transformClass(
 
     let guaranteedSuperBeforeFinish = !!classState.bareSupers.size;
 
-    const superRef = classState.superName || t.identifier("Function");
     let thisRef = function() {
       const ref = path.scope.generateDeclaredUidIdentifier("this");
       thisRef = () => t.cloneNode(ref);
@@ -390,7 +389,7 @@ export default function transformClass(
     };
 
     for (const bareSuper of classState.bareSupers) {
-      wrapSuperCall(bareSuper, superRef, thisRef, body);
+      wrapSuperCall(bareSuper, classState.superName, thisRef, body);
 
       if (guaranteedSuperBeforeFinish) {
         bareSuper.find(function(parentPath) {
@@ -638,7 +637,7 @@ export default function transformClass(
       classRef: classState.node.id
         ? t.identifier(classState.node.id.name)
         : classState.scope.generateUidIdentifier("class"),
-      superName: classState.node.superClass || t.identifier("Function"),
+      superName: classState.node.superClass,
       isDerived: !!classState.node.superClass,
       constructorBody: t.blockStatement([]),
     });

packages/babel-plugin-transform-classes/test/fixtures/loose/default-super/exec.js

@@ -0,0 +1,17 @@
+class Test {
+  constructor() {
+    return super.constructor;
+  }
+
+  static test() {
+    return super.constructor;
+  }
+}
+
+// Instances
+expect(Object.getPrototypeOf(Test.prototype)).toBe(Object.prototype);
+expect(new Test()).toBe(Object);
+
+// Static
+expect(Object.getPrototypeOf(Test)).toBe(Function.prototype);
+expect(Test.test()).toBe(Function);

packages/babel-plugin-transform-classes/test/fixtures/loose/default-super/input.js

@@ -0,0 +1,17 @@
+class Test {
+  constructor() {
+    return super.constructor;
+  }
+
+  static test() {
+    return super.constructor;
+  }
+}
+
+// Instances
+expect(Object.getPrototypeOf(Test.prototype)).toBe(Object.prototype);
+expect(new Test()).toBe(Object);
+
+// Static
+expect(Object.getPrototypeOf(Test)).toBe(Function.prototype);
+expect(Test.test()).toBe(Function);

packages/babel-plugin-transform-classes/test/fixtures/loose/default-super/output.js

@@ -0,0 +1,22 @@
+var Test =
+/*#__PURE__*/
+function () {
+  "use strict";
+
+  function Test() {
+    return Object.prototype.constructor;
+  }
+
+  Test.test = function test() {
+    return Function.prototype.constructor;
+  };
+
+  return Test;
+}(); // Instances
+
+
+expect(Object.getPrototypeOf(Test.prototype)).toBe(Object.prototype);
+expect(new Test()).toBe(Object); // Static
+
+expect(Object.getPrototypeOf(Test)).toBe(Function.prototype);
+expect(Test.test()).toBe(Function);

packages/babel-plugin-transform-classes/test/fixtures/loose/super-function-fallback/output.js

@@ -1,5 +1,5 @@
 var Test = function Test() {
   "use strict";
 
-  Function.prototype.hasOwnProperty.call(this, "test");
+  Object.prototype.hasOwnProperty.call(this, "test");
 };

packages/babel-plugin-transform-classes/test/fixtures/spec/default-super/exec.js

@@ -0,0 +1,17 @@
+class Test {
+  constructor() {
+    return super.constructor;
+  }
+
+  static test() {
+    return super.constructor;
+  }
+}
+
+// Instances
+expect(Object.getPrototypeOf(Test.prototype)).toBe(Object.prototype);
+expect(new Test()).toBe(Object);
+
+// Static
+expect(Object.getPrototypeOf(Test)).toBe(Function.prototype);
+expect(Test.test()).toBe(Function);

packages/babel-plugin-transform-classes/test/fixtures/spec/default-super/input.js

@@ -0,0 +1,17 @@
+class Test {
+  constructor() {
+    return super.constructor;
+  }
+
+  static test() {
+    return super.constructor;
+  }
+}
+
+// Instances
+expect(Object.getPrototypeOf(Test.prototype)).toBe(Object.prototype);
+expect(new Test()).toBe(Object);
+
+// Static
+expect(Object.getPrototypeOf(Test)).toBe(Function.prototype);
+expect(Test.test()).toBe(Function);

packages/babel-plugin-transform-classes/test/fixtures/spec/default-super/output.js

@@ -0,0 +1,25 @@
+var Test =
+/*#__PURE__*/
+function () {
+  "use strict";
+
+  function Test() {
+    babelHelpers.classCallCheck(this, Test);
+    return babelHelpers.get(babelHelpers.getPrototypeOf(Test.prototype), "constructor", babelHelpers.assertThisInitialized(this));
+  }
+
+  babelHelpers.createClass(Test, null, [{
+    key: "test",
+    value: function test() {
+      return babelHelpers.get(babelHelpers.getPrototypeOf(Test), "constructor", this);
+    }
+  }]);
+  return Test;
+}(); // Instances
+
+
+expect(Object.getPrototypeOf(Test.prototype)).toBe(Object.prototype);
+expect(new Test()).toBe(Object); // Static
+
+expect(Object.getPrototypeOf(Test)).toBe(Function.prototype);
+expect(Test.test()).toBe(Function);