Add type check for AsyncIterator

Author: slowcheetah

tests/type-definitions/helpers.ts

@@ -50,3 +50,17 @@ export interface CoreJSIteratorLike<T, TReturn = any, TNext = any> extends Itera
   join(...args: any[]): string;
 }
 export type CoreJSIteratorAndIteratorLike<T> = CoreJSIteratorLike<T> & Iterator<T>;
+
+export interface CoreJSAsyncIteratorLike<T, TReturn = any, TNext = any> {
+  drop(...args: any[]): any;
+  every(...args: any[]): any;
+  filter(...args: any[]): any;
+  find(...args: any[]): any;
+  flatMap(...args: any[]): any;
+  forEach(...args: any[]): any;
+  map(...args: any[]): any;
+  reduce(...args: any[]): any;
+  some(...args: any[]): any;
+  take(...args: any[]): any;
+  toArray(...args: any[]): any;
+}

tests/type-definitions/pure/proposals/async-iterator-helper.test.ts

@@ -11,9 +11,9 @@ import some from '@core-js/pure/full/async-iterator/some';
 import take from '@core-js/pure/full/async-iterator/take';
 import toArray from '@core-js/pure/full/async-iterator/to-array';
 import toAsync from '@core-js/pure/full/iterator/to-async';
-// import $AsyncIterator from '@core-js/pure/full/async-iterator'; // todo
-import { CoreJSPromiseAndPromiseLike } from '../../helpers';
+import { CoreJSAsyncIteratorLike, CoreJSPromiseAndPromiseLike } from '../../helpers';
 
+const aitn: CoreJSAsyncIteratorLike<number> = from([1]);
 const aiton = from([1, 2, 3]);
 aiton.next();
 aiton.toArray();