getUserMedia() spoof

spoof.js

function fakeGetUserMedia(options) {
    var canvas = document.createElement('canvas');
    canvas.width = 640;
    canvas.height = 480;
    var result = new Promise((resolve, reject) => {
        setTimeout(() => {
            var ctx = canvas.getContext('2d');
            ctx.font = '100px sans-serif';
            ctx.fillText('💩', 200, 200);
            resolve(canvas.captureStream(30));
        }, 100);
    });
    return result;
}

navigator.getUserMedia = fakeGetUserMedia;
navigator.webkitGetUserMedia = fakeGetUserMedia;
navigator.mediaDevices.getUserMedia = fakeGetUserMedia;