fix omitting the result of proxing .return in `%IteratorHelperProto…

…type%.return`, close #1116

CHANGELOG.md

@@ -2,6 +2,7 @@
 ##### Unreleased
 - Considering `document.all` as an object in some missed cases, see [ECMAScript Annex B 3.6](https://tc39.es/ecma262/#sec-IsHTMLDDA-internal-slot)
 - Avoiding unnecessary promise creation and validation result in `%WrapForValid(Async)IteratorPrototype%.return`, [proposal-iterator-helpers/215](https://github.com/tc39/proposal-iterator-helpers/pull/215)
+- Fixed omitting the result of proxing `.return` in `%IteratorHelperPrototype%.return`, [#1116](https://github.com/zloirock/core-js/issues/1116)
 - Fixed the order creation of properties of iteration result object of some iterators (`value` should be created before `done`)
 - Fixed some cases of Safari < 13 bug - silent on non-writable array `.length` setting
 - Fixed `ArrayBuffer.length` in V8 ~ Chrome 27-

packages/core-js/internals/iterator-create-proxy.js

@@ -1,6 +1,5 @@
 'use strict';
 var call = require('../internals/function-call');
-var anObject = require('../internals/an-object');
 var create = require('../internals/object-create');
 var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
 var defineBuiltIns = require('../internals/define-built-ins');
@@ -39,16 +38,19 @@ var createIteratorProxyPrototype = function (IS_ITERATOR) {
     'return': function () {
       var state = getInternalState(this);
       var iterator = state.iterator;
-      var innerIterator = state.innerIterator;
       state.done = true;
+      if (IS_ITERATOR) {
+        var returnMethod = getMethod(iterator, 'return');
+        return returnMethod ? call(returnMethod, iterator) : { value: undefined, done: true };
+      }
+      var innerIterator = state.innerIterator;
       if (innerIterator) try {
         iteratorClose(innerIterator, 'return');
       } catch (error) {
         return iteratorClose(iterator, 'throw', error);
       }
-      var returnMethod = getMethod(iterator, 'return');
-      var result = returnMethod && call(returnMethod, iterator);
-      return IS_ITERATOR && returnMethod ? result : { value: returnMethod ? anObject(result).value : undefined, done: true };
+      iteratorClose(iterator, 'return');
+      return { value: undefined, done: true };
     }
   });