<!doctype html>
<title>VTTRegion()</title>
<link rel="help" href="https://w3c.github.io/webvtt/#dom-vttregion-vttregion">
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<div id=log></div>
<script>
test(function() {
    var region = new VTTRegion();
    assert_true(region instanceof VTTRegion, "instanceof");

    assert_equals(region.scroll, "");
    assert_equals(region.viewportAnchorX, 0);
    assert_equals(region.viewportAnchorY, 100);
    assert_equals(region.regionAnchorX, 0);
    assert_equals(region.regionAnchorY, 100);
    assert_equals(region.lines, 3);
    assert_equals(region.width, 100);
}, document.title + " initial values");

test(function() {
    var region = new VTTRegion();
    region.scroll = "invalid-scroll-value";
    assert_equals(region.scroll, "");

    checkValues([-1, 101], "IndexSizeError");
    checkValues([-Infinity, Infinity, NaN], TypeError);

    function assert_throws_something(error, func) {
        if (typeof error == "string") {
            assert_throws_dom(error, func);
        } else {
            assert_throws_js(error, func);
        }
    }

    function checkValues(invalidValues, exception) {
        for (var value of invalidValues) {
            assert_throws_something(exception, function() { region.viewportAnchorX = value; });
            assert_equals(region.viewportAnchorX, 0);
            assert_throws_something(exception, function() { region.viewportAnchorY = value; });
            assert_equals(region.viewportAnchorY, 100);
            assert_throws_something(exception, function() { region.regionAnchorX = value; });
            assert_equals(region.regionAnchorX, 0);
            assert_throws_something(exception, function() { region.regionAnchorY = value; });
            assert_equals(region.regionAnchorY, 100);
            assert_throws_something(exception, function() { region.width = value; });
            assert_equals(region.width, 100);
        }
    }

    assert_equals(region.lines, 3);

    region.lines = 130;
    assert_equals(region.lines, 130);
    region.viewportAnchorX = 64;
    assert_equals(region.viewportAnchorX, 64);
    region.viewportAnchorY = 32;
    assert_equals(region.viewportAnchorY, 32);
    region.regionAnchorX = 16;
    assert_equals(region.regionAnchorX, 16);
    region.regionAnchorY = 8;
    assert_equals(region.regionAnchorY, 8);
    region.width = 42;
    assert_equals(region.width, 42);
}, document.title + " mutations");
</script>