1 files changed, 23 insertions, 0 deletions
diff --git a/testing/web-platform/tests/portals/resources/focus-page-with-autofocus.html b/testing/web-platform/tests/portals/resources/focus-page-with-autofocus.html
new file mode 100644
index 0000000000..d498ef6335
--- /dev/null
+++ b/testing/web-platform/tests/portals/resources/focus-page-with-autofocus.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<body>
+  <button id="one">one</button>
+  <button id="two" autofocus>two</button>
+  <button id="three">three</button>
+  <script>
+    function messageHandler(e) {
+      if (e.data === 'check-active-element') {
+        window.requestAnimationFrame(() => {
+          let autofocusedButton = document.querySelector('#two');
+          e.source.postMessage(document.activeElement === autofocusedButton);
+        });
+      }
+    }
+
+    window.portalHost.onmessage = messageHandler;
+    window.onportalactivate = e => {
+      let portal = e.adoptPredecessor();
+      portal.onmessage = messageHandler;
+      document.body.appendChild(portal);
+    }
+  </script>
+</body>