avoid extra promise creation

tc39/proposal-iterator-helpers#197
zloirock · Jul 9, 2022 · d05ee98 · d05ee98
1 parent 361c111
commit d05ee98
Show file tree

Hide file tree

Showing 2 changed files with 5 additions and 4 deletions.
diff --git a/packages/core-js/internals/async-iterator-create-proxy.js b/packages/core-js/internals/async-iterator-create-proxy.js
@@ -1,5 +1,6 @@
 'use strict';
 var call = require('../internals/function-call');
+var perform = require('../internals/perform');
 var anObject = require('../internals/an-object');
 var create = require('../internals/object-create');
 var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
@@ -32,10 +33,11 @@ module.exports = function (nextHandler, IS_ITERATOR) {
   AsyncIteratorProxy.prototype = defineBuiltIns(create(AsyncIteratorPrototype), {
     next: function next() {
       var that = this;
-      return new Promise(function (resolve) {
+      var result = perform(function () {
         var state = getInternalState(that);
-        resolve(state.done ? { done: true, value: undefined } : anObject(call(nextHandler, state, Promise)));
+        return state.done ? { done: true, value: undefined } : anObject(call(nextHandler, state, Promise));
       });
+      return result.error ? Promise.reject(result.value) : Promise.resolve(result.value);
     },
     'return': function (value) {
       var that = this;

diff --git a/packages/core-js/modules/esnext.async-iterator.from.js b/packages/core-js/modules/esnext.async-iterator.from.js
@@ -1,7 +1,6 @@
 // https://github.com/tc39/proposal-iterator-helpers
 var $ = require('../internals/export');
 var call = require('../internals/function-call');
-var anObject = require('../internals/an-object');
 var toObject = require('../internals/to-object');
 var isPrototypeOf = require('../internals/object-is-prototype-of');
 var AsyncIteratorPrototype = require('../internals/async-iterator-prototype');
@@ -17,7 +16,7 @@ var AsyncFromSyncIterator = require('../internals/async-from-sync-iterator');
 var ASYNC_ITERATOR = wellKnownSymbol('asyncIterator');
 
 var AsyncIteratorProxy = createAsyncIteratorProxy(function () {
-  return anObject(call(this.next, this.iterator));
+  return call(this.next, this.iterator);
 }, true);
 
 $({ target: 'AsyncIterator', stat: true, forced: true }, {