JavaScript 以编程方式检查是否正在使用相机

Question

I'm writing functional tests for a video chat app.

I want to make sure that when the user leaves the meeting the camera turns off. So, I'm trying to check if the camera is being used or not.

Is there a way to do that programatically? I couldn't find any methods on navigator.MediaDevices that say "hey your camera is being used".

Answer 1

Here is how I solved it in TestCafe by "spying" on getUserMedia :

const overWriteGetUserMedia = ClientFunction(() => {
  const realGetUserMedia = navigator.mediaDevices.getUserMedia;
  const allRequestedTracks = [];
  navigator.mediaDevices.getUserMedia = constraints =>
    realGetUserMedia(constraints).then(stream => {
      stream.getTracks().forEach(track => {
        allRequestedTracks.push(track);
      });
      return stream;
    });
  return allRequestedTracks;
});

test('leaving a meeting should end streams', async t => {
  const allRequestedTracks = await overWriteGetUserMedia();

  await t.wait(5000); // wait for streams to start;

  await t.click(screen.getByLabelText(/leave/i));
  await t.click(screen.getByLabelText(/yes, leave the meeting/i));

  await t.wait(1000); // wait for navigation;

  const actual = !allRequestedTracks.some(track => !track.ended);
  const expected = true;

  await t.expect(actual).eql(expected);
});

Answer 2

You can use navigator.mediaDevices.getUserMedia method to get access of user camera, and user active value to check is camera already activated.

If user block the permission to the camera you will receive an error.

Hope this will be work for you.