test(itemlist): Fix ItemList test console warning (#569)

Author: Mingze

src/components/ItemList/__mocks__/ItemRow.tsx

@@ -0,0 +1,7 @@
+import React from 'react';
+import classNames from 'classnames';
+import { Props } from '../ItemRow';
+
+export default React.forwardRef(({ className, isActive, ...rest }: Props, ref: React.Ref<HTMLDivElement>) => (
+    <div ref={ref} className={classNames(className, 'ba-ItemRow', { 'is-active': isActive })} {...rest} />
+));

src/components/ItemList/__tests__/ItemList-test.tsx

@@ -5,7 +5,7 @@ import ItemList, { Props } from '../ItemList';
 import { Collaborator } from '../../../@types';
 
 jest.mock('scroll-into-view-if-needed', () => jest.fn());
-jest.mock('../ItemRow', () => 'div');
+jest.mock('../ItemRow');
 
 describe('ItemList', () => {
     const defaults: Props<Collaborator> = {