react-native/Libraries/Lists/__tests__/VirtualizedList-test.js

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 *
 * @format
 * @emails oncall+react_native
 */
'use strict';

const React = require('React');
const ReactTestRenderer = require('react-test-renderer');

const VirtualizedList = require('VirtualizedList');

describe('VirtualizedList', () => {
  it('renders simple list', () => {
    const component = ReactTestRenderer.create(
      <VirtualizedList
        data={[{key: 'i1'}, {key: 'i2'}, {key: 'i3'}]}
        renderItem={({item}) => <item value={item.key} />}
        getItem={(data, index) => data[index]}
        getItemCount={data => data.length}
      />,
    );
    expect(component).toMatchSnapshot();
  });

  it('renders empty list', () => {
    const component = ReactTestRenderer.create(
      <VirtualizedList
        data={[]}
        renderItem={({item}) => <item value={item.key} />}
        getItem={(data, index) => data[index]}
        getItemCount={data => data.length}
      />,
    );
    expect(component).toMatchSnapshot();
  });

  it('renders null list', () => {
    const component = ReactTestRenderer.create(
      <VirtualizedList
        data={undefined}
        renderItem={({item}) => <item value={item.key} />}
        getItem={(data, index) => data[index]}
        getItemCount={data => 0}
      />,
    );
    expect(component).toMatchSnapshot();
  });

  it('renders empty list with empty component', () => {
    const component = ReactTestRenderer.create(
      <VirtualizedList
        data={[]}
        ListEmptyComponent={() => <empty />}
        ListFooterComponent={() => <footer />}
        ListHeaderComponent={() => <header />}
        getItem={(data, index) => data[index]}
        getItemCount={data => data.length}
        renderItem={({item}) => <item value={item.key} />}
      />,
    );
    expect(component).toMatchSnapshot();
  });

  it('renders list with empty component', () => {
    const component = ReactTestRenderer.create(
      <VirtualizedList
        data={[{key: 'hello'}]}
        ListEmptyComponent={() => <empty />}
        getItem={(data, index) => data[index]}
        getItemCount={data => data.length}
        renderItem={({item}) => <item value={item.key} />}
      />,
    );
    expect(component).toMatchSnapshot();
  });

  it('renders all the bells and whistles', () => {
    const component = ReactTestRenderer.create(
      <VirtualizedList
        ItemSeparatorComponent={() => <separator />}
        ListEmptyComponent={() => <empty />}
        ListFooterComponent={() => <footer />}
        ListHeaderComponent={() => <header />}
        data={new Array(5).fill().map((_, ii) => ({id: String(ii)}))}
        getItem={(data, index) => data[index]}
        getItemCount={data => data.length}
        getItemLayout={({index}) => ({length: 50, offset: index * 50})}
        inverted={true}
        keyExtractor={(item, index) => item.id}
        onRefresh={jest.fn()}
        refreshing={false}
        renderItem={({item}) => <item value={item.id} />}
      />,
    );
    expect(component).toMatchSnapshot();
  });

  it('test getItem functionality where data is not an Array', () => {
    const component = ReactTestRenderer.create(
      <VirtualizedList
        data={new Map([['id_0', {key: 'item_0'}]])}
        getItem={(data, index) => data.get('id_' + index)}
        getItemCount={(data: Map) => data.size}
        renderItem={({item}) => <item value={item.key} />}
      />,
    );
    expect(component).toMatchSnapshot();
  });

  it('handles separators correctly', () => {
    const infos = [];
    const component = ReactTestRenderer.create(
      <VirtualizedList
        ItemSeparatorComponent={props => <separator {...props} />}
        data={[{key: 'i0'}, {key: 'i1'}, {key: 'i2'}]}
        renderItem={info => {
          infos.push(info);
          return <item title={info.item.key} />;
        }}
        getItem={(data, index) => data[index]}
        getItemCount={data => data.length}
      />,
    );
    expect(component).toMatchSnapshot();
    infos[1].separators.highlight();
    expect(component).toMatchSnapshot();
    infos[2].separators.updateProps('leading', {press: true});
    expect(component).toMatchSnapshot();
    infos[1].separators.unhighlight();
  });

  it('handles nested lists', () => {
    const component = ReactTestRenderer.create(
      <VirtualizedList
        data={[{key: 'outer0'}, {key: 'outer1'}]}
        renderItem={outerInfo => (
          <VirtualizedList
            data={[
              {key: outerInfo.item.key + ':inner0'},
              {key: outerInfo.item.key + ':inner1'},
            ]}
            horizontal={outerInfo.item.key === 'outer1'}
            renderItem={innerInfo => {
              return <item title={innerInfo.item.key} />;
            }}
            getItem={(data, index) => data[index]}
            getItemCount={data => data.length}
          />
        )}
        getItem={(data, index) => data[index]}
        getItemCount={data => data.length}
      />,
    );
    expect(component).toMatchSnapshot();
  });

  it('returns the viewableItems correctly in the onViewableItemsChanged callback after changing the data', () => {
    const ITEM_HEIGHT = 800;
    let data = [{key: 'i1'}, {key: 'i2'}, {key: 'i3'}];
    const nativeEvent = {
      contentOffset: {y: 0, x: 0},
      layoutMeasurement: {width: 300, height: 600},
      contentSize: {width: 300, height: data.length * ITEM_HEIGHT},
      zoomScale: 1,
      contentInset: {right: 0, top: 0, left: 0, bottom: 0},
    };
    const onViewableItemsChanged = jest.fn();
    const props = {
      data,
      renderItem: ({item}) => <item value={item.key} />,
      getItem: (data, index) => data[index],
      getItemCount: data => data.length,
      getItemLayout: (data, index) => ({
        length: ITEM_HEIGHT,
        offset: ITEM_HEIGHT * index,
        index,
      }),
      onViewableItemsChanged,
    };

    const component = ReactTestRenderer.create(<VirtualizedList {...props} />);

    const instance = component.getInstance();

    instance._onScrollBeginDrag({nativeEvent});
    instance._onScroll({
      timeStamp: 1000,
      nativeEvent,
    });

    expect(onViewableItemsChanged).toHaveBeenCalledTimes(1);
    expect(onViewableItemsChanged).toHaveBeenLastCalledWith(
      expect.objectContaining({
        viewableItems: [expect.objectContaining({isViewable: true, key: 'i1'})],
      }),
    );
    data = [{key: 'i4'}, ...data];
    component.update(<VirtualizedList {...props} data={data} />);

    instance._onScroll({
      timeStamp: 2000,
      nativeEvent: {
        ...nativeEvent,
        contentOffset: {y: 100, x: 0},
      },
    });

    expect(onViewableItemsChanged).toHaveBeenCalledTimes(2);
    expect(onViewableItemsChanged).toHaveBeenLastCalledWith(
      expect.objectContaining({
        viewableItems: [expect.objectContaining({isViewable: true, key: 'i4'})],
      }),
    );
  });
});