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EDITING: index.test.ts

// @ts-nocheck
/*
 * Copyright (C) 2021 - present Instructure, Inc.
 *
 * This file is part of Canvas.
 *
 * Canvas is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the Free
 * Software Foundation, version 3 of the License.
 *
 * Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

import awaitElement from '../index'

describe('awaitElement', () => {
  beforeAll(() => {
    jest.useFakeTimers()
  })

afterAll(() => {
    jest.runAllTimers()
    jest.useRealTimers()
  })

beforeEach(() => {
    jest
      .spyOn(window, 'requestAnimationFrame')
      .mockImplementation(function (cb: (number) => void): number {
        return window.setTimeout(function () {
          cb(0)
        }, 50)
      })
    jest.spyOn(window, 'cancelAnimationFrame').mockImplementation(function (timer: number): void {
      window.clearTimeout(timer)
    })
  })

afterEach(() => {
    ;(window.requestAnimationFrame as jest.Mock).mockRestore()
    ;(window.cancelAnimationFrame as jest.Mock).mockRestore()
  })

it('detects a new DOM element when it’s added', async () => {
    const elt = document.createElement('div')
    elt.id = 'lolly'

const promise = awaitElement('lolly', 1000)
    document.body.append(elt)
    jest.runAllTimers()
    const result = await promise
    expect(result.id).toBe('lolly')
  })

it('detects a DOM element that’s already there', async () => {
    const elt = document.createElement('div')
    elt.id = 'popsicle'
    document.body.append(elt)

const promise = awaitElement('popsicle', 1000)
    jest.runAllTimers()
    const result = await promise
    expect(result.id).toBe('popsicle')
  })

it('rejects the Promise if the element never gets added', async () => {
    const promise = awaitElement('lost-to-eternity', 1000)
    try {
      jest.advanceTimersByTime(1050) // oops we waited just a little too long
      await promise
      throw new Error('fails')
    } catch (e) {
      expect(e).toEqual(new Error('Timeout waiting for element to appear'))
    }
  })

it('waits the requested amount of time before rejecting', async () => {
    const elt = document.createElement('div')
    elt.id = 'just-in-time'

const promise = awaitElement('just-in-time', 3000)

jest.advanceTimersByTime(2949) // wait until it's almost too late
    document.body.append(elt) // ...then add the element in the nick of time
    jest.runAllTimers()

const result = await promise
    expect(result.id).toBe('just-in-time')
  })
})

CANCEL

Name	Type	Size	Modified	Actions
↩ ..	DIR	—	—
📄 index.test.ts	TS	2.8 KB	2023-09-24 03:39	EDIT