1 files changed, 20 insertions, 0 deletions
diff --git a/testing/web-platform/tests/portals/resources/portals-adopt-predecessor.html b/testing/web-platform/tests/portals/resources/portals-adopt-predecessor.html
new file mode 100644
index 0000000000..66d47d12ac
--- /dev/null
+++ b/testing/web-platform/tests/portals/resources/portals-adopt-predecessor.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<body>
+</body>
+<script>
+  var searchParams = new URL(location).searchParams;
+  var test = searchParams.get("test");
+  var portal = document.createElement("portal");
+  portal.src = `portals-adopt-predecessor-portal.html?test=${test}`;
+  portal.onload = () => {
+    portal.activate().then(() => {
+      window.addEventListener("portalactivate", e => {
+        window.opener.postMessage({test, message: "passed"}, "*");
+      });
+      window.portalHost.addEventListener("message", e => {
+        window.opener.postMessage({test, message: e.data}, "*");
+      });
+    });
+  }
+  document.body.appendChild(portal);
+</script>