sousa-gecko/testing/web-platform/tests/css/css-values/tree-counting/sibling-function-invalidation.html

<!DOCTYPE html>
<title>CSS Values and Units Test: Invalidation for sibling-index() and sibling-count()</title>
<link rel="help" href="https://drafts.csswg.org/css-values-5/#tree-counting">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
  #t1 {
    width: calc(10px * sibling-index());
    height: 50px;
    background: teal;
  }
</style>
<div>
  <div id="rm1"></div>
  <div></div>
  <div></div>
  <div></div>
  <div></div>
  <div id="t1"></div>
</div>
<script>
  test(() => assert_equals(t1.offsetWidth, 60), "Initially 6th sibling");
  test(() => {
    rm1.remove();
    assert_equals(t1.offsetWidth, 50);
  }, "5th sibling after removal");
</script>

<style>
  #t2 {
    width: 50px;
    height: calc(10px * sibling-count());
    background: teal;
  }
</style>
<div>
  <div id="t2"></div>
  <div></div>
  <div></div>
  <div></div>
  <div></div>
  <div id="rm2"></div>
</div>
<script>
  test(() => assert_equals(t2.offsetHeight, 60), "Initially 6 siblings");
  test(() => {
    rm2.remove();
    assert_equals(t2.offsetHeight, 50);
  }, "5 siblings after removal");
</script>

<style>
  #t3::before {
    content: "";
    font-size: calc(10px * sibling-index());
    font-weight: calc(10 * sibling-count());
  }
</style>
<div>
  <div id="rm3"></div>
  <div id="t3"></div>
  <div></div>
</div>
<script>
  test(() => {
    const styles = getComputedStyle(t3, "::before");
    assert_equals(styles.fontSize, "20px", "sibling-index() is 2 initially");
    assert_equals(styles.fontWeight, "30", "sibling-count() is 3 initially");
  }, "::before sibling-count() and sibling-index() initially");
  test(() => {
    rm3.remove();
    const styles = getComputedStyle(t3, "::before");
    assert_equals(styles.fontSize, "10px", "sibling-index() is 1 after removal");
    assert_equals(styles.fontWeight, "20", "sibling-count() is 2 after removal");
  }, "::before sibling-count() and sibling-index() after removal");
</script>

<style>
  #t4::after {
    content: "";
    font-size: calc(10px * sibling-index());
    font-weight: calc(10 * sibling-count());
  }
</style>
<div>
  <div id="rm4"></div>
  <div></div>
  <div id="t4"></div>
  <div></div>
</div>
<script>
  test(() => {
    const styles = getComputedStyle(t4, "::after");
    assert_equals(styles.fontSize, "30px", "sibling-index() is 3 initially");
    assert_equals(styles.fontWeight, "40", "sibling-count() is 4 initially");
  }, "::after sibling-count() and sibling-index() initially");
  test(() => {
    rm4.remove();
    const styles = getComputedStyle(t4, "::after");
    assert_equals(styles.fontSize, "20px", "sibling-index() is 2 after removal");
    assert_equals(styles.fontWeight, "30", "sibling-count() is 3 after removal");
  }, "::after sibling-count() and sibling-index() after removal");
</script>

<style>
  #t5::first-letter {
    font-size: calc(10px * sibling-index());
    font-weight: calc(10 * sibling-count());
  }
</style>
<div>
  <div id="rm5"></div>
  <div id="t5">X</div>
  <div>X</div>
</div>
<script>
  test(() => {
    const styles = getComputedStyle(t5, "::first-letter");
    assert_equals(styles.fontSize, "20px", "sibling-index() is 2 initially");
    assert_equals(styles.fontWeight, "30", "sibling-count() is 3 initially");
  }, "::first-letter sibling-count() and sibling-index() initially");
  test(() => {
    rm5.remove();
    const styles = getComputedStyle(t5, "::first-letter");
    assert_equals(styles.fontSize, "10px", "sibling-index() is 1 after removal");
    assert_equals(styles.fontWeight, "20", "sibling-count() is 2 after removal");
  }, "::first-letter sibling-count() and sibling-index() after removal");
</script>

<style>
  #t6::first-line {
    font-size: calc(10px * sibling-index());
    font-weight: calc(10 * sibling-count());
  }
</style>
<div>
  <div id="rm6"></div>
  <div>X</div>
  <div id="t6">X</div>
  <div>X</div>
</div>
<script>
  test(() => {
    const styles = getComputedStyle(t6, "::first-line");
    assert_equals(styles.fontSize, "30px", "sibling-index() is 3 initially");
    assert_equals(styles.fontWeight, "40", "sibling-count() is 4 initially");
  }, "::first-line sibling-count() and sibling-index() initially");
  test(() => {
    rm6.remove();
    const styles = getComputedStyle(t6, "::first-line");
    assert_equals(styles.fontSize, "20px", "sibling-index() is 2 after removal");
    assert_equals(styles.fontWeight, "30", "sibling-count() is 3 after removal");
  }, "::first-line sibling-count() and sibling-index() after removal");
</script>