1 files changed, 39 insertions, 0 deletions
diff --git a/testing/web-platform/tests/css/cssom-view/screen-detached-frame.html b/testing/web-platform/tests/css/cssom-view/screen-detached-frame.html
new file mode 100644
index 0000000000..1d566d10f1
--- /dev/null
+++ b/testing/web-platform/tests/css/cssom-view/screen-detached-frame.html
@@ -0,0 +1,39 @@
+<!doctype html>
+<meta charset="utf-8">
+<link rel="help" href="https://drafts.csswg.org/cssom-view/#dom-window-screen">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1858977">
+<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
+<link rel="author" href="https://mozilla.org" title="Mozilla">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe></iframe>
+<script>
+onload = function() {
+  test(() => {
+    let frame = document.querySelector("iframe");
+    let win = frame.contentWindow;
+    frame.remove();
+    assert_true(!!win.screen, "Window.screen should be available");
+    for (let prop of ["top", "left", "width", "height"]) {
+      let availProp = "avail" + prop[0].toUpperCase() + prop.substr(1);
+      if (prop == "width" || prop == "height") {
+        assert_true(prop in win.screen, prop + "must be implemented per spec")
+        assert_true(availProp in win.screen, availProp + "must be implemented per spec")
+      }
+      if (prop in win.screen) {
+        assert_equals(win.screen[prop], 0, prop);
+      }
+      if (availProp in win.screen) {
+        assert_equals(win.screen[availProp], 0, availProp);
+      }
+    }
+
+    // https://drafts.csswg.org/cssom-view/#dom-screen-colordepth
+    //   If the user agent does not know the color depth or does not want to
+    //   return it for privacy considerations, it should return 24.
+    for (let prop of ["colorDepth", "pixelDepth"]) {
+      assert_equals(win.screen[prop], 24, prop);
+    }
+  }, "Window.screen on detached frame");
+};
+</script>