setupJest.js

require('jest-fetch-mock').enableMocks()
require('@testing-library/jest-dom')
require('@testing-library/jest-native/extend-expect')

jest.mock('react-native/Libraries/Animated/src/NativeAnimatedHelper')

process.env.REACT_APP_PIN = '987654'

const MockDate = require('mockdate')
const frameTime = 10

global.requestAnimationFrame = cb => {
  // Default implementation of requestAnimationFrame calls setTimeout(cb, 0),
  // which will result in a cascade of timers - this generally pisses off test runners
  // like Jest who watch the number of timers created and assume an infinite recursion situation
  // if the number gets too large.
  //
  // Setting the timeout simulates a frame every 1/100th of a second
  setTimeout(cb, frameTime)
}

global.timeTravel = (time = frameTime) => {
  const tickTravel = () => {
    // The React Animations module looks at the elapsed time for each frame to calculate its
    // new position
    const now = Date.now()
    MockDate.set(new Date(now + frameTime))

    // Run the timers forward
    jest.advanceTimersByTime(frameTime)
  }

  // Step through each of the frames
  const frames = time / frameTime
  let framesEllapsed
  for (framesEllapsed = 0; framesEllapsed < frames; framesEllapsed++) {
    tickTravel()
  }
}

MockDate.set('2020-04-20')