timeStamp in event created by `createEvent` is not used

• @testing-library/react version: 11.2.0
• Testing Framework and version: jest-26.0.15
• DOM Environment: jsdom-16.4.0

Relevant code or config:

import { createEvent } from '@testing-library/react'

test('event uses timeStamp', () => {
  const mockEvent = createEvent.click(document.body, { timeStamp: 1000000 })
  expect(mockEvent.timeStamp).toBe(1000000)
})

What you did:

• used createEvent to create an event with a manipulated timeStamp

What happened:

• the created event had a native timeStamp

Reproduction:

See test case above

Problem description:

Overwriting timeStamp is one of the documented use cases for createEvent, see https://testing-library.com/docs/dom-testing-library/api-events/#createeventeventname

Suggested solution:

As a workaround, one can use Object.defineProperty(event, ‘timeStamp’, { value: 1000000 });

[drorheller]

Hi, I’d like to update the doc on this

[eps1lon]

Thanks for the report.

Can you set this property with the native event API? I think browsers set this automatically i.e. you’re not supposed to be able to manipulate them with conventional APIs (https://developer.mozilla.org/en-US/docs/Web/API/Event/timeStamp).

Though Object.defineProperty works. I’m leaning towards following the DOM API here. I think it should be obvious from your test if you’re mocking something.