1 files changed, 39 insertions, 0 deletions
diff --git a/testing/web-platform/tests/intersection-observer/fixed-position-child-scroll.html b/testing/web-platform/tests/intersection-observer/fixed-position-child-scroll.html
new file mode 100644
index 0000000000..9360209046
--- /dev/null
+++ b/testing/web-platform/tests/intersection-observer/fixed-position-child-scroll.html
@@ -0,0 +1,39 @@
+<!doctype html>
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="./resources/intersection-observer-test-utils.js"></script>
+<div style="position: fixed; top: 0; left: 0">
+  <div id="target" style="width: 100px; height: 100px"></div>
+</div>
+<div id="log" style="height: 2000px"></div>
+<script>
+var entries = [];
+
+runTestCycle(function() {
+  var observer = new IntersectionObserver(function(changes) {
+    entries = entries.concat(changes)
+  });
+  observer.observe(target);
+  entries = entries.concat(observer.takeRecords());
+  assert_equals(entries.length, 0, 'No initial notifications.');
+  runTestCycle(step0, 'First rAF.');
+}, 'Fixed-position intersection observer on scroll');
+
+function step0() {
+  window.scrollTo(0, 1000);
+  runTestCycle(step1, 'scrollTo(0, 1000)');
+  checkLastEntry(entries, 0,
+                 [0, 100, 0, 100, 0, 100, 0, 100, 0,
+                  document.documentElement.clientWidth, 0, document.documentElement.clientHeight,
+                  true]);
+}
+
+function step1() {
+  window.scrollTo(0, 0);
+  checkLastEntry(entries, 0,
+                 [0, 100, 0, 100, 0, 100, 0, 100, 0,
+                  document.documentElement.clientWidth, 0, document.documentElement.clientHeight,
+                  true]);
+}
+</script>