Fixes 5701 - Functions declared as methods define a prototype property

ES19 requires that, unless otherwise stated, all methods should have a prototype. ChakraCore adds prototypes to methods defined in objects. In order to not allow prototypes to be added to methods defined in objects, the ErrorOnNew flag is atted to the pNodeFnc's FuncInfo's attributes. Class constructors are methods but are defined to have prototypes, so they are not given the ErrorOnNew flag.

Author: wyrichte

lib/Runtime/ByteCode/ByteCodeGenerator.cpp

@@ -1267,6 +1267,14 @@ static Js::FunctionInfo::Attributes GetFunctionInfoAttributes(ParseNodeFnc * pno
     if (pnodeFnc->IsMethod())
     {
         attributes = (Js::FunctionInfo::Attributes)(attributes | Js::FunctionInfo::Attributes::Method);
+
+        // #sec-runtime-semantics-classdefinitionevaluation calls #sec-makeconstructor. #sec-makeconstructor
+        // creates a prototype. Thus a method that is a class constructor has a prototype and should not
+        // throw an error when new is called on the method.
+        if (!pnodeFnc->IsClassConstructor())
+        {
+            attributes = (Js::FunctionInfo::Attributes)(attributes | Js::FunctionInfo::Attributes::ErrorOnNew);
+        }
     }
     if (pnodeFnc->IsGenerator())
     {

lib/Runtime/Library/InJavascript/Intl.js.bc.32b.h

@@ -4,4 +4,4 @@ bug16252562.js(9, 3)
 	Unhandled parse opcode for asm.js
 
 Asm.js compilation failed.
-new.target: Bar() {console.log(`new.target: ${new.target}`);}
+new.target: function () { console.log(`new.target: ${new.target}`); }

lib/Runtime/Library/InJavascript/Intl.js.bc.64b.h

@@ -11,4 +11,4 @@ function AsmModule(stdlib, foreign) {
   }
   return foo;
 }
-AsmModule(this, {Bar() {console.log(`new.target: ${new.target}`);}})();
+AsmModule(this, { Bar: function () { console.log(`new.target: ${new.target}`); } })();

lib/Runtime/Library/InJavascript/Intl.js.nojit.bc.32b.h

@@ -0,0 +1,41 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+var failed = false;
+
+var o = {
+    f() { }
+}
+
+if (o.f.hasOwnProperty("prototype")) {
+    failed = true;
+    WScript.Echo("Failed: a method within an object literal should not have a prototype");
+}
+
+try {
+    new o.f();
+    failed = true;
+    WScript.Echo("Failed: a method within an object literal should not have a prototype and thus new should not be valid");
+}
+catch (e) {
+}
+
+class C {
+    f() { }
+}
+
+if (new C().f.hasOwnProperty("prototype")) {
+    failed = true;
+    WScript.Echo("Failed: a method within a class should not have a prototype");
+}
+
+if (!(new C().constructor.hasOwnProperty("prototype"))) {
+    failed = true;
+    WScript.Echo("Failed: a class' constructor should have a prototype");
+}
+
+if (!failed) {
+    WScript.Echo("Pass");
+}

lib/Runtime/Library/InJavascript/Intl.js.nojit.bc.64b.h

@@ -46,4 +46,9 @@
       <files>shadow2.js</files>
     </default>
   </test>
+  <test>
+    <default>
+      <files>NoPrototypeForMethod.js</files>
+    </default>
+  </test>
 </regress-exe>

test/AsmJs/bug16252562.baseline

@@ -116,12 +116,19 @@ var tests = [
         }
     },
     {
-        name: "Proxy of Object literal method should be constructable",
+        name: "Proxy of Object literal function should be constructable",
         body() {
-            let testingMethod = {test() {}}
+            let testingMethod = {test:function() {}}
             testConstructProxy(testingMethod.test, false);
         }
     },
+    {
+        name: "Proxy of Object literal method should not be constructable",
+        body() {
+            let testingMethod = { test() { } }
+            testConstructProxy(testingMethod.test, true);
+        }
+    },
     {
         name: "Proxy of Date object should be constructable",
         body() {