electron/spec/api-desktop-capturer-spec.js

const chai = require('chai')
const dirtyChai = require('dirty-chai')
const chaiAsPromised = require('chai-as-promised')
const { desktopCapturer, ipcRenderer, remote } = require('electron')
const { screen } = remote
const features = process.electronBinding('features')
const { emittedOnce } = require('./events-helpers')

const { expect } = chai
chai.use(dirtyChai)
chai.use(chaiAsPromised)

const isCI = remote.getGlobal('isCi')

describe('desktopCapturer', () => {
  before(function () {
    if (!features.isDesktopCapturerEnabled() || process.arch.indexOf('arm') === 0) {
      // It's been disabled during build time.
      this.skip()
      return
    }

    if (isCI && process.platform === 'win32') {
      this.skip()
    }
  })

  it('should return a non-empty array of sources', async () => {
    const sources = await desktopCapturer.getSources({ types: ['window', 'screen'] })
    expect(sources).to.be.an('array').that.is.not.empty()
  })

  it('throws an error for invalid options', async () => {
    const promise = desktopCapturer.getSources(['window', 'screen'])
    expect(promise).to.be.eventually.rejectedWith(Error, 'Invalid options')
  })

  it('does not throw an error when called more than once (regression)', async () => {
    const sources1 = await desktopCapturer.getSources({ types: ['window', 'screen'] })
    expect(sources1).to.be.an('array').that.is.not.empty()

    const sources2 = await desktopCapturer.getSources({ types: ['window', 'screen'] })
    expect(sources2).to.be.an('array').that.is.not.empty()
  })

  it('responds to subsequent calls of different options', async () => {
    const promise1 = desktopCapturer.getSources({ types: ['window'] })
    expect(promise1).to.not.eventually.be.rejected()

    const promise2 = desktopCapturer.getSources({ types: ['screen'] })
    expect(promise2).to.not.eventually.be.rejected()
  })

  it('returns an empty display_id for window sources on Windows and Mac', async () => {
    // Linux doesn't return any window sources.
    if (process.platform !== 'win32' && process.platform !== 'darwin') return

    const { BrowserWindow } = remote
    const w = new BrowserWindow({ width: 200, height: 200 })

    const sources = await desktopCapturer.getSources({ types: ['window'] })
    w.destroy()
    expect(sources).to.be.an('array').that.is.not.empty()
    for (const { display_id: displayId } of sources) {
      expect(displayId).to.be.a('string').and.be.empty()
    }
  })

  it('returns display_ids matching the Screen API on Windows and Mac', async () => {
    if (process.platform !== 'win32' && process.platform !== 'darwin') return

    const displays = screen.getAllDisplays()
    const sources = await desktopCapturer.getSources({ types: ['screen'] })
    expect(sources).to.be.an('array').of.length(displays.length)

    for (let i = 0; i < sources.length; i++) {
      expect(sources[i].display_id).to.equal(displays[i].id.toString())
    }

    it('returns empty sources when blocked', async () => {
      ipcRenderer.send('handle-next-desktop-capturer-get-sources')
      const sources = await desktopCapturer.getSources({ types: ['screen'] })
      expect(sources).to.be.empty()
    })
  })

  it('disabling thumbnail should return empty images', async () => {
    const { BrowserWindow } = remote
    const w = new BrowserWindow({ show: false, width: 200, height: 200 })
    const wShown = emittedOnce(w, 'show')
    w.show()
    await wShown

    const sources = await desktopCapturer.getSources({ types: ['window', 'screen'], thumbnailSize: { width: 0, height: 0 } })
    w.destroy()
    expect(sources).to.be.an('array').that.is.not.empty()
    for (const { thumbnail: thumbnailImage } of sources) {
      expect(thumbnailImage).to.be.a('NativeImage')
      expect(thumbnailImage.isEmpty()).to.be.true()
    }
  })
})