1 files changed, 75 insertions, 0 deletions
diff --git a/testing/web-platform/tests/scroll-animations/scroll-timelines/animation-with-display-none.html b/testing/web-platform/tests/scroll-animations/scroll-timelines/animation-with-display-none.html
new file mode 100644
index 0000000000..a62916833c
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+++ b/testing/web-platform/tests/scroll-animations/scroll-timelines/animation-with-display-none.html
@@ -0,0 +1,75 @@
+<html class="reftest-wait">
+<title>Scroll timeline with Web Animation and transition from display:none to display:block</title>
+<link rel="help" href="https://drafts.csswg.org/scroll-animations/">
+<meta name="assert" content="Scroll timeline should properly handle going from display:none to display:block">
+<link rel="match" href="animation-ref.html">
+
+<script src="/web-animations/testcommon.js"></script>
+<script src="/common/reftest-wait.js"></script>
+
+<style>
+  #box {
+    width: 100px;
+    height: 100px;
+    background-color: green;
+  }
+
+  #covered {
+    width: 100px;
+    height: 100px;
+    background-color: red;
+  }
+
+  #scroller {
+    overflow: auto;
+    height: 100px;
+    width: 100px;
+    will-change: transform; /* force compositing */
+  }
+
+  .removed {
+    display: none;
+  }
+
+  #contents {
+    height: 1000px;
+    width: 100%;
+  }
+</style>
+
+<div id="box"></div>
+<div id="covered"></div>
+<div id="scroller">
+  <div id="contents"><p>Scrolling Contents</p></div>
+</div>
+
+<script>
+  const box = document.getElementById('box');
+  const effect = new KeyframeEffect(box,
+    [
+    { transform: 'translateY(0)', opacity: 1 },
+    { transform: 'translateY(200px)', opacity: 0 }
+    ], {
+      duration: 1000,
+    }
+  );
+
+  const scroller = document.getElementById('scroller');
+  scroller.classList.add('removed');
+  const timeline = new ScrollTimeline(
+      { source: scroller, orientation: 'block' });
+  const animation = new Animation(effect, timeline);
+  animation.play();
+
+  waitForAnimationFrames(2).then(_ => {
+    scroller.classList.remove('removed');
+    animation.ready.then(() => {
+      const maxScroll = scroller.scrollHeight - scroller.clientHeight;
+      scroller.scrollTop = 0.5 * maxScroll;
+
+      waitForAnimationFrames(2).then(_ => {
+        takeScreenshot();
+      });
+    });
+  });
+</script>