css/css-mixins/function-container-self.html

<!DOCTYPE html>
<title>Custom Functions: @container can not query self</title>
<link rel="help" href="https://drafts.csswg.org/css-mixins-1/#conditional-rules">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
  #container, #target {
    container-type: size;
  }
  #container {
    width: 100px;
    height: 100px;
  }
  #target {
    width: 50px;
    height: 50px;
  }
  @function --f() {
    result: A;
    @container (width = 100px) {
      result: B;
    }
    @container (width = 50px) {
      result: C;
    }
  }
  #target {
    --actual: --f();
  }
</style>

<div id=container>
  <div id=target>
  </div>
</div>

<script>
  test(() => {
    // Even though #target is a CQ container, the @container rules should
    // not evaluate against that element.
    assert_equals(getComputedStyle(target).getPropertyValue('--actual'), 'B');
  });
</script>