fake time fixture in playwright

fake-time.fixtures.ts

import { test as base } from '@playwright/test';

const setFakeTime = async (dateTime: string, page: Page): Promise<void> => {
  const fakeNow = new Date(dateTime).valueOf();
  const setFakeTime = async (dateTime: string, page: Page): Promise<void> => {
  const fakeNow = new Date(dateTime).valueOf();
  await page.addInitScript(`{
    // Extend Date constructor to default to fakeNow
    Date = class extends Date {
      constructor(...args) {
        if (args.length === 0) {
          super(${fakeNow});
        } else {
          super(...args);
        }
      }
    }
    // Override Date.now() to start from fakeNow
    const __DateNowOffset = ${fakeNow} - Date.now();
    const __DateNow = Date.now;
    Date.now = () => __DateNow() + __DateNowOffset;
  }`);
};
  
export const test = base.extend({
  fakeTime?: string;
  page: async ({ fakeTime, page }, use) => {
  if (fakeTime) {
    await setFakeTime(fakeTime, page);
  }  
  await use(page);
  },
});
  
  
// use it in your tests by specifying: 
  test.use({fakeTime: 'March 14 2022 13:37:11 UTC'});