Function sleep

packages/react-dom/src/__tests__/ReactTestUtilsAct-test.js:22–28

(period)

global.IS_REACT_ACT_ENVIRONMENT = true;

function sleep(period) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve(true);
    }, period);
  });
}

describe('React.act()', () => {
  afterEach(() => {