ant-design/components/spin/__tests__/delay.test.js

import React from 'react';
import { mount } from 'enzyme';
import Spin from '..';

describe('delay spinning', () => {
  it('should render with delay when it\'s mounted with spinning=true and delay', () => {
    const wrapper = mount(<Spin spinning delay={500} />);
    expect(
      wrapper
        .find('.ant-spin')
        .at(0)
        .hasClass('ant-spin-spinning'),
    ).toEqual(false);
  });

  it('should render when delay is init set', async () => {
    const wrapper = mount(<Spin spinning delay={100} />);

    expect(
      wrapper
        .find('.ant-spin')
        .at(0)
        .hasClass('ant-spin-spinning'),
    ).toEqual(false);

    // use await not jest.runAllTimers()
    // because of https://github.com/facebook/jest/issues/3465
    await new Promise(resolve => setTimeout(resolve, 500));
    wrapper.update();

    expect(
      wrapper
        .find('.ant-spin')
        .at(0)
        .hasClass('ant-spin-spinning'),
    ).toEqual(true);
  });
});