Only use getPrototypeOf if setPrototypeOf is implemented

babel · May 18, 2018 · 15aa9c2 · 15aa9c2
1 parent 4a0f40a
commit 15aa9c2
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
@@ -421,9 +421,9 @@ helpers.inheritsLoose = () => template.program.ast`
 
 helpers.getPrototypeOf = () => template.program.ast`
   export default function _getPrototypeOf(o) {
-    _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) {
-      return o.__proto__;
-    };
+    _getPrototypeOf = Object.setPrototypeOf
+      ? Object.getPrototypeOf
+      : function _getPrototypeOf(o) { return o.__proto__; };
     return _getPrototypeOf(o);
   }
 `;