<!doctype html>
<title>container-name invalidation</title>
<link rel="help" href="https://drafts.csswg.org/css-contain-3/#container-name">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="support/cq-testcommon.js"></script>
<style>
  div {
    color: black;
  }
  #outer {
    container-name: c1;
    container-type: inline-size;
    width: 300px;
  }

  #inner {
    container-name: c2;
    container-type: inline-size;
    width: 200px;
  }

  #intermediate {
    width: 250px;
  }

  @container c1 (width: 250px) {
    #child {
      color: green;
    }
  }
</style>
<div id=outer>
  <div id=intermediate>
    <div id=inner>
      <div id=child>Test</div>
    </div>
  </div>
</div>
<script>
  setup(() => assert_implements_container_queries());

  test(function(t) {
    t.add_cleanup(() => { outer.style = ''; });

    assert_equals(getComputedStyle(child).color, 'rgb(0, 0, 0)');

    outer.style.width = '250px';
    assert_equals(getComputedStyle(child).color, 'rgb(0, 128, 0)');

    outer.style.width = '251px';
    assert_equals(getComputedStyle(child).color, 'rgb(0, 0, 0)');
  }, 'Changing a named container invalidates relevant descendants');

  test(function(t) {
    t.add_cleanup(() => {
      outer.style = '';
      intermediate.style = '';
    });

    assert_equals(getComputedStyle(child).color, 'rgb(0, 0, 0)');

    // #intermediate becomes the new container.
    intermediate.style = 'container-name:c1; container-type:inline-size';
    assert_equals(getComputedStyle(child).color, 'rgb(0, 128, 0)');

    // #outer becomes the container again.
    intermediate.style = '';
    assert_equals(getComputedStyle(child).color, 'rgb(0, 0, 0)');

    outer.style.width = '250px';
    assert_equals(getComputedStyle(child).color, 'rgb(0, 128, 0)');
  }, 'Changing container-name invalidates relevant descendants');
</script>
