draw-element-image-empty.tentative.html

Enable keyboard shortcuts

This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /html/canvas/element/manual/draw-element-image/draw-element-image-empty.tentative.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<title>Canvas.drawElementImage: do not throw on empty elements</title>

<link rel="help" href="https://github.com/WICG/html-in-canvas">

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

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

<canvas id="canvas" width="100" height="100">

  <div id="child"></div>

</canvas>

<script>

  'use strict';

  promise_test(async t => {

    // Add `layoutsubtree` and assert that `drawElementImage` throws when used

    // prior to `onpaint` firing.

    canvas.setAttribute('layoutsubtree', 'true');

    let ctx = canvas.getContext('2d');

    assert_throws_dom(

      'InvalidStateError',

      () => ctx.drawElementImage(child, 0, 0),

      'drawElementImage should throw prior to onpaint.');

    // Wait for `onpaint` and verify that `drawElementImage` does not throw,

    // even though #child is an empty div.

    await new Promise(r => canvas.onpaint = r);

    ctx.drawElementImage(child, 0, 0);

  }, 'canvas drawElementImage should not throw on empty elements.');

</script>