Call Object.getPrototypeOf twice to avoid referencing this.constructor

Author: ChadKillingsworth

src/com/google/javascript/jscomp/RewriteAsyncFunctions.java

@@ -246,24 +246,21 @@ private void convertAsyncFunction(NodeTraversal t, LexicalContext functionContex
     boolean needsSuperTranspilation = compiler.getOptions().needsTranspilationFrom(FeatureSet.ES6);
     for (String replacedMethodName : functionContext.replacedSuperProperties) {
       // MS Edge 17 cannot properly capture references to "super" in an arrow function.
-      // If we are not transpiling classes, switch to using Object.getPrototypeOf(this.constructor)
+      // If we are not transpiling classes, switch to using Object.getPrototypeOf(this)
       // as a replacement for super.
       // If we are transpiling classes, the super reference will be handled elsewhere.
       Node superReference;
       if (needsSuperTranspilation) {
         superReference = IR.superNode();
-      } else if (originalFunction.getParent().isStaticMember()) {
+      } else {
         // static super: Object.getPrototypeOf(this);
         superReference =
             IR.call(IR.getprop(IR.name("Object"), IR.string("getPrototypeOf")), IR.thisNode());
-      } else {
-        // instance super: Object.getPrototypeOf(this.constructor).prototype
-        superReference =
-            IR.getprop(
-                IR.call(
-                    IR.getprop(IR.name("Object"), IR.string("getPrototypeOf")),
-                    IR.getprop(IR.thisNode(), IR.string("constructor"))),
-                IR.string("prototype"));
+        if (!originalFunction.getParent().isStaticMember()) {
+          // instance super: Object.getPrototypeOf(Object.getPrototypeOf(this))
+          superReference =
+              IR.call(IR.getprop(IR.name("Object"), IR.string("getPrototypeOf")), superReference);
+        }
       }
 
       // const super$get$x = () => super.x;

src/com/google/javascript/jscomp/RewriteAsyncIteration.java

@@ -566,22 +566,21 @@ private void prependTempVarDeclarations(LexicalContext ctx, NodeTraversal t) {
       // }
       //
       // MS Edge 17 cannot properly capture references to "super" in an arrow function.
-      // If we are not transpiling classes, switch to using Object.getPrototypeOf(this.constructor)
+      // If we are not transpiling classes, switch to using Object.getPrototypeOf(this)
       // as a replacement for super.
       // If we are transpiling classes, the super reference will be handled elsewhere.
       Node superReference;
       if (needsSuperTranspilation) {
         superReference = IR.superNode();
-      } else if (ctx.function.getParent().isStaticMember()) {
-        // static super: Object.getPrototypeOf(this.constructor);
-        superReference =
-            IR.call(
-                IR.getprop(IR.name("Object"), IR.string("getPrototypeOf")),
-                IR.getprop(IR.thisNode(), IR.string("constructor")));
       } else {
-        // instance super: Object.getPrototypeOf(this)
+        // static super: Object.getPrototypeOf(this);
         superReference =
             IR.call(IR.getprop(IR.name("Object"), IR.string("getPrototypeOf")), IR.thisNode());
+        if (!ctx.function.getParent().isStaticMember()) {
+          // instance super: Object.getPrototypeOf(Object.getPrototypeOf(this))
+          superReference =
+              IR.call(IR.getprop(IR.name("Object"), IR.string("getPrototypeOf")), superReference);
+        }
       }
 
       Node arrowFunction =

test/com/google/javascript/jscomp/IntegrationTest.java

@@ -3989,7 +3989,7 @@ public void testAsyncFunctionSuper() {
             "class Baz extends Foo {",
             "  bar() {",
             "    const $jscomp$async$this = this, $jscomp$async$super$get$bar =",
-            "        () => Object.getPrototypeOf(this.constructor).prototype.bar;",
+            "        () => Object.getPrototypeOf(Object.getPrototypeOf(this)).bar;",
             "    return $jscomp.asyncExecutePromiseGeneratorFunction(function*() {",
             "      yield Promise.resolve();",
             "      $jscomp$async$super$get$bar().call($jscomp$async$this);",
@@ -4043,7 +4043,7 @@ public void testAsyncIterationSuper() {
             "  bar() {",
             "    const $jscomp$asyncIter$this = this,",
             "          $jscomp$asyncIter$super$get$bar =",
-            "              () => Object.getPrototypeOf(this.constructor).prototype.bar;",
+            "              () => Object.getPrototypeOf(Object.getPrototypeOf(this)).bar;",
             "    return new $jscomp.AsyncGeneratorWrapper(function*() {",
             "      $jscomp$asyncIter$super$get$bar().call($jscomp$asyncIter$this).next();",
             "    }());",

test/com/google/javascript/jscomp/RewriteAsyncFunctionsTest.java

@@ -167,7 +167,7 @@ public void testInnerSuperCallEs2015Out() {
             "  m() {",
             "    const $jscomp$async$this = this;",
             "    const $jscomp$async$super$get$m =",
-            "        () => Object.getPrototypeOf(this.constructor).prototype.m;",
+            "        () => Object.getPrototypeOf(Object.getPrototypeOf(this)).m;",
             "    return $jscomp.asyncExecutePromiseGeneratorFunction(",
             "        function* () {",
             "          return $jscomp$async$super$get$m().call($jscomp$async$this);",

test/com/google/javascript/jscomp/RewriteAsyncIterationTest.java

@@ -226,7 +226,7 @@ public void testInnerSuperReferenceInAsyncGenerator() {
             "class X extends A {",
             "  m() {",
             "    const $jscomp$asyncIter$super$get$m =",
-            "        () => Object.getPrototypeOf(this.constructor).prototype.m;",
+            "        () => Object.getPrototypeOf(Object.getPrototypeOf(this)).m;",
             "    return new $jscomp.AsyncGeneratorWrapper(",
             "        function* () {",
             "          const tmp = $jscomp$asyncIter$super$get$m();",