1 files changed, 11 insertions, 0 deletions
diff --git a/testing/web-platform/tests/screen-details/isExtended.tentative.https.window.js b/testing/web-platform/tests/screen-details/isExtended.tentative.https.window.js
new file mode 100644
index 0000000000..3c814ae3d9
--- /dev/null
+++ b/testing/web-platform/tests/screen-details/isExtended.tentative.https.window.js
@@ -0,0 +1,11 @@
+// META: global=window
+'use strict';
+
+promise_test(async t => {
+  assert_equals(typeof self.screen.isExtended, 'boolean');
+}, 'screen.isExtended is present');
+
+promise_test(async t => {
+  let iframe = document.body.appendChild(document.createElement('iframe'));
+  assert_equals(typeof iframe.contentWindow.screen.isExtended, 'boolean');
+}, 'screen.isExtended is present for attached iframes');