feat: Add virtual list mock for test usage

Author: zombieJ

src/List.tsx

@@ -19,7 +19,7 @@ const ScrollStyle = {
   overflowAnchor: 'none',
 };
 
-type RenderFunc<T> = (
+export type RenderFunc<T> = (
   item: T,
   index: number,
   props: { style: React.CSSProperties },

src/mock.tsx

@@ -0,0 +1,27 @@
+import * as React from 'react';
+import OriginList from './List';
+import Filler from './Filler';
+
+class List<T> extends OriginList<T> {
+  render() {
+    const {
+      style,
+      component: Component = 'div',
+      height,
+      itemHeight,
+      data,
+      children,
+      itemKey,
+      onSkipRender,
+      ...restProps
+    } = this.props;
+
+    return (
+      <Component style={{ ...style, height }} {...restProps}>
+        <Filler height={height}>{this.renderChildren(data, 0, children)}</Filler>
+      </Component>
+    );
+  }
+}
+
+export default List;

src/utils/itemUtil.ts

@@ -79,10 +79,6 @@ export function getElementScrollPercentage(element: HTMLElement | null) {
  * But if not provided, downgrade to `findDOMNode` to get the real dom element.
  */
 export function getNodeHeight(node: HTMLElement) {
-  if (!node) {
-    return 0;
-  }
-
   return findDOMNode(node).offsetHeight;
 }
 

tests/mock.test.js

@@ -0,0 +1,25 @@
+import React from 'react';
+import { mount } from 'enzyme';
+import MockList from '../src/mock';
+import Filler from '../src/Filler';
+
+describe('MockList', () => {
+  it('correct render', () => {
+    const wrapper = mount(
+      <MockList data={[0, 1, 2]} itemKey={id => id}>
+        {id => <span>{id}</span>}
+      </MockList>,
+    );
+
+    expect(wrapper.find(Filler).length).toBeTruthy();
+
+    for (let i = 0; i < 3; i += 1) {
+      expect(
+        wrapper
+          .find('span')
+          .at(i)
+          .key(),
+      ).toBe(String(i));
+    }
+  });
+});