Only freeze helper args if weakmap present

Author: mixonic

packages/ember-glimmer/lib/utils/references.js

@@ -1,5 +1,6 @@
 import { symbol, EmptyObject } from 'ember-utils';
 import {
+  HAS_NATIVE_WEAKMAP,
   get,
   set,
   tagForProperty,
@@ -289,8 +290,10 @@ export class SimpleHelperReference extends CachedReference {
       let namedValue = named.value();
 
       runInDebug(() => {
-        Object.freeze(positionalValue);
-        Object.freeze(namedValue);
+        if (HAS_NATIVE_WEAKMAP) {
+          Object.freeze(positionalValue);
+          Object.freeze(namedValue);
+        }
       });
 
       let result = helper(positionalValue, namedValue);
@@ -324,8 +327,10 @@ export class SimpleHelperReference extends CachedReference {
     let namedValue = named.value();
 
     runInDebug(() => {
-      Object.freeze(positionalValue);
-      Object.freeze(namedValue);
+      if (HAS_NATIVE_WEAKMAP) {
+        Object.freeze(positionalValue);
+        Object.freeze(namedValue);
+      }
     });
 
     return helper(positionalValue, namedValue);
@@ -354,8 +359,10 @@ export class ClassBasedHelperReference extends CachedReference {
     let namedValue = named.value();
 
     runInDebug(() => {
-      Object.freeze(positionalValue);
-      Object.freeze(namedValue);
+      if (HAS_NATIVE_WEAKMAP) {
+        Object.freeze(positionalValue);
+        Object.freeze(namedValue);
+      }
     });
 
     return instance.compute(positionalValue, namedValue);

packages/ember-metal/lib/index.js

@@ -43,6 +43,7 @@ export {
   setDispatchOverride
 } from './error_handler';
 export {
+  HAS_NATIVE_WEAKMAP,
   META_DESC,
   meta,
   peekMeta

packages/ember-metal/lib/meta.js

@@ -460,7 +460,7 @@ if (isEnabled('mandatory-setter')) {
   };
 }
 
-const HAS_NATIVE_WEAKMAP = (function() {
+export const HAS_NATIVE_WEAKMAP = (function() {
   // detect if `WeakMap` is even present
   let hasWeakMap = typeof WeakMap === 'function';
   if (!hasWeakMap) { return false; }