fix order of arguments validation in Array.fromAsync polyfill

Author: zloirock

CHANGELOG.md

@@ -15,6 +15,7 @@
 - Fixed double `.return()` calling in case of throwing error in this method in the internal `iterate` helper that affected some polyfills
 - Fixed closing iterator on `IteratorValue` errors in the internal `iterate` helper that affected some polyfills
 - Fixed iterator closing in `Array.from` polyfill on failure to create array property
+- Fixed order of arguments validation in `Array.fromAsync` polyfill
 - Fixed order of arguments validation in `Array.prototype.flat` polyfill
 - Fixed handling strings as iterables in `Iterator.{ zip, zipKeyed }` polyfills
 - Fixed some cases of iterators closing in `Iterator.{ zip, zipKeyed }` polyfills

packages/core-js/internals/array-from-async.js

@@ -1,7 +1,6 @@
 'use strict';
 var bind = require('../internals/function-bind-context');
 var uncurryThis = require('../internals/function-uncurry-this');
-var toObject = require('../internals/to-object');
 var isConstructor = require('../internals/is-constructor');
 var getAsyncIterator = require('../internals/get-async-iterator');
 var getIterator = require('../internals/get-iterator');
@@ -32,20 +31,19 @@ SafeArrayIterator.prototype.next = function () {
 
 // `Array.fromAsync` method implementation
 // https://github.com/tc39/proposal-array-from-async
-module.exports = function fromAsync(asyncItems /* , mapfn = undefined, thisArg = undefined */) {
+module.exports = function fromAsync(items /* , mapfn = undefined, thisArg = undefined */) {
   var C = this;
   var argumentsLength = arguments.length;
   var mapfn = argumentsLength > 1 ? arguments[1] : undefined;
   var thisArg = argumentsLength > 2 ? arguments[2] : undefined;
   return new (getBuiltIn('Promise'))(function (resolve) {
-    var O = toObject(asyncItems);
     if (mapfn !== undefined) mapfn = bind(mapfn, thisArg);
-    var usingAsyncIterator = getMethod(O, ASYNC_ITERATOR);
-    var usingSyncIterator = usingAsyncIterator ? undefined : getIteratorMethod(O) || safeArrayIterator;
+    var usingAsyncIterator = getMethod(items, ASYNC_ITERATOR);
+    var usingSyncIterator = usingAsyncIterator ? undefined : getIteratorMethod(items) || safeArrayIterator;
     var A = isConstructor(C) ? new C() : [];
     var iterator = usingAsyncIterator
-      ? getAsyncIterator(O, usingAsyncIterator)
-      : new AsyncFromSyncIterator(getIteratorDirect(getIterator(O, usingSyncIterator)));
+      ? getAsyncIterator(items, usingAsyncIterator)
+      : new AsyncFromSyncIterator(getIteratorDirect(getIterator(items, usingSyncIterator)));
     resolve(toArray(iterator, mapfn, A));
   });
 };