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();
    }
  });
});