chromium/src/third_party/blink/web_tests/fast/canvas/canvas-arc-connecting-line.html

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>

<script>
test(function(t) {
    var canvas = document.createElement('canvas');
    canvas.width = canvas.height = 300;
    var ctx = canvas.getContext('2d');
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    ctx.lineJoin = 'bevel';
    ctx.lineWidth = 12;
    ctx.beginPath();
    ctx.arc(200, 50, 40, Math.PI / 2, -Math.PI / 2, false);
    ctx.arc(100, 50, 40, Math.PI / 2, -Math.PI / 2, false);
    ctx.stroke();
    
    var imageData = ctx.getImageData(0, 0, 1, 1);
    var imgdata = imageData.data;
    assert_equals(imgdata[0], 0);
    assert_equals(imgdata[1], 255);
    assert_equals(imgdata[2], 0);
    
    imageData = ctx.getImageData(125, 30, 1, 1);
    imgdata = imageData.data;
    assert_equals(imgdata[0], 0);
    assert_equals(imgdata[1], 255);
    assert_equals(imgdata[2], 0);
    
    imageData = ctx.getImageData(125, 70, 1, 1);
    imgdata = imageData.data;
    assert_equals(imgdata[0], 0);
    assert_equals(imgdata[1], 0);
    assert_equals(imgdata[2], 0);
}, 'Test that canvas arc()s are connected by a straight line. There should be two C-shapes with a line from the bottom of the left one to the top of the right one.');
</script>