[Refactor] minimize dynamic lookups of __proto__

paulmillr · Mar 23, 2023 · abcecb9 · abcecb9
1 parent 99be112
commit abcecb9
Showing 1 changed file with 5 additions and 5 deletions.
diff --git a/es6-shim.js b/es6-shim.js
@@ -1535,7 +1535,7 @@
     var ES5ObjectShims = {
       // 19.1.3.9
       // shim from https://gist.github.com/WebReflection/5593554
-      setPrototypeOf: (function (Object, magic) {
+      setPrototypeOf: (function (Object) {
         var set;
 
         var checkArgs = function (O, proto) {
@@ -1555,16 +1555,16 @@
 
         try {
           // this works already in Firefox and Safari
-          set = Object.getOwnPropertyDescriptor(Object.prototype, magic).set;
+          set = Object.getOwnPropertyDescriptor(Object.prototype, '__proto__').set;
           _call(set, {}, null);
         } catch (e) {
-          if (Object.prototype !== {}[magic]) {
+          if (Object.prototype !== ({}).__proto__) { // eslint-disable-line no-proto
             // IE < 11 cannot be shimmed
             return;
           }
           // probably Chrome or some old Mobile stock browser
           set = function (proto) {
-            this[magic] = proto;
+            this.__proto__ = proto; // eslint-disable-line no-proto
           };
           // please note that this will **not** work
           // in those browsers that do not inherit
@@ -1584,7 +1584,7 @@
           // we can even delete Object.prototype.__proto__;
         }
         return setPrototypeOf;
-      }(Object, '__proto__'))
+      }(Object))
     };
 
     defineProperties(Object, ES5ObjectShims);