1 files changed, 50 insertions, 0 deletions
diff --git a/testing/web-platform/tests/speculation-rules/prerender/resources/message-boxes.html b/testing/web-platform/tests/speculation-rules/prerender/resources/message-boxes.html
new file mode 100644
index 0000000000..8e0a6e874f
--- /dev/null
+++ b/testing/web-platform/tests/speculation-rules/prerender/resources/message-boxes.html
@@ -0,0 +1,50 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/speculation-rules/prerender/resources/utils.js"></script>
+<script>
+function runAlertTest() {
+  window.alert('Hello! Preprendering!');
+  return 'no block';
+}
+
+function runConfirmTest() {
+  const result = window.confirm('Are you preprendering page?');
+  return 'the return value is ' + (result === true ? 'yes' : 'no');
+}
+
+function runPromptTest() {
+  const result = window.prompt('Are you preprendering page?',
+    'the default value');
+  return 'the return value is ' + (result === null ? 'null' : result);
+}
+
+const params = new URLSearchParams(location.search);
+
+const uid = params.get('uid');
+
+// The main test page (restriction-message-boxes.html) loads the
+// initiator page, then the initiator page will prerender itself with the
+// `prerendering` parameter.
+const isPrerendering = params.has('prerendering');
+
+if (isPrerendering) {
+  // Test web APIs on the pages.
+  const bc = new PrerenderChannel('prerender-channel', uid);
+  assert_true(document.prerendering);
+  if (params.has('alert')) {
+    bc.postMessage(runAlertTest());
+  } else if (params.has('confirm')) {
+    bc.postMessage(runConfirmTest());
+  } else if (params.has('prompt')) {
+    bc.postMessage(runPromptTest());
+  }
+  bc.close();
+  window.close();
+} else {
+  // Initiator pages should prerender the prerendering page.
+  const url = new URL(document.URL);
+  url.searchParams.append('prerendering', '');
+  startPrerendering(url);
+}
+</script>