<!doctype html>
<html>
<head>
    <title>MediaRecorder Error</title>
    <link rel="help" href="https://w3c.github.io/mediacapture-record/MediaRecorder.html#mediarecorder">
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
</head>
<body>
<canvas id="canvas" width="320" height="320">
</canvas>
<script>
    function createAudioStream() {
        let ac = new AudioContext();
        let osc = ac.createOscillator();
        let dest = ac.createMediaStreamDestination();
        osc.connect(dest);
        return dest.stream;
    }

    function createVideoStream() {
        let canvas = document.getElementById("canvas");
        canvas.getContext('2d').lineTo(10, 10);
        return canvas.captureStream();
    }

    function drawSomethingOnCanvas() {
        let canvas = document.getElementById("canvas");
        // Drawing something on the canvas generates a frame in its captured stream.
        let context = canvas.getContext("2d");
        context.fillStyle = "red";
        context.fillRect(0, 0, 10, 10);
    }

    async_test(t => {
        let video = createVideoStream();
        let audio = createAudioStream();
        let recorder = new MediaRecorder(video);
        recorder.onerror = t.step_func(mediaRecorderErrorEvent => {
            assert_true(mediaRecorderErrorEvent instanceof MediaRecorderErrorEvent, 'the type of event should be MediaRecorderErrorEvent');
            assert_equals(mediaRecorderErrorEvent.error.name, 'InvalidModificationError', 'the type of error should be InvalidModificationError when track has been added or removed');
            assert_true(mediaRecorderErrorEvent.isTrusted, 'isTrusted should be true when the event is created by C++');
            assert_equals(recorder.state, "inactive", "MediaRecorder has been stopped after adding a track to stream");
            t.done();
        });
        recorder.start();
        assert_equals(recorder.state, "recording", "MediaRecorder has been started successfully");
        video.addTrack(audio.getAudioTracks()[0]);
        drawSomethingOnCanvas();
        t.step_timeout(() => {
            assert_unreached("error event is not fired after 2 seconds");
        }, 2000);
    }, "MediaRecorder will stop recording when any of track is added and error event will be fired");

    async_test(t => {
        let video = createVideoStream();
        let recorder = new MediaRecorder(video);
        recorder.onerror = t.step_func(mediaRecorderErrorEvent => {
            assert_true(mediaRecorderErrorEvent instanceof MediaRecorderErrorEvent, 'the type of event should be MediaRecorderErrorEvent');
            assert_equals(mediaRecorderErrorEvent.error.name, 'InvalidModificationError', 'the type of error should be InvalidModificationError when track has been added or removed');
            assert_true(mediaRecorderErrorEvent.isTrusted, 'isTrusted should be true when the event is created by C++');
            assert_equals(recorder.state, "inactive", "MediaRecorder has been stopped after removing a track from stream");
            t.done();
        });
        recorder.start();
        assert_equals(recorder.state, "recording", "MediaRecorder has been started successfully");
        video.removeTrack(video.getVideoTracks()[0]);
        drawSomethingOnCanvas();
        t.step_timeout(() => {
            assert_unreached("error event is not fired after 2 seconds");
        }, 2000);
    }, "MediaRecorder will stop recording when any of track is removed and error event will be fired");

    test(t => {
        let video = createVideoStream();
        let recorder = new MediaRecorder(video);
        recorder.start();
        assert_equals(recorder.state, "recording", "MediaRecorder has been started successfully");
        assert_throws_dom("InvalidStateError", function() {
            recorder.start();
        });
    }, "MediaRecorder cannot start recording when MediaRecorder' state is not inactive and an InvalidStateError should be thrown");
</script>
</body>
</html>