1 files changed, 28 insertions, 0 deletions
diff --git a/testing/web-platform/tests/selection/Document-open.html b/testing/web-platform/tests/selection/Document-open.html
new file mode 100644
index 0000000000..9e3cb28124
--- /dev/null
+++ b/testing/web-platform/tests/selection/Document-open.html
@@ -0,0 +1,28 @@
+<!doctype html>
+<title>Selection Document.open() tests</title>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+"use strict";
+
+const iframe = document.createElement("iframe");
+async_test(t => {
+  iframe.onload = t.step_func_done(() => {
+    const originalSelection = iframe.contentWindow.getSelection();
+    assert_equals(originalSelection.rangeCount, 0, "rangeCount must initially be 0");
+    iframe.contentDocument.body.appendChild(iframe.contentDocument.createTextNode("foo"));
+    const range = iframe.contentDocument.createRange();
+    range.selectNodeContents(iframe.contentDocument.body);
+    iframe.contentWindow.getSelection().addRange(range);
+    assert_equals(originalSelection.rangeCount, 1, "rangeCount must be 1 after adding a range");
+
+    iframe.contentDocument.open();
+
+    assert_equals(iframe.contentWindow.getSelection(), originalSelection, "After document.open(), the Selection object must be the same");
+    assert_equals(iframe.contentWindow.getSelection().rangeCount, 1, "After document.open(), rangeCount must still be 1");
+    document.body.removeChild(iframe);
+  });
+  document.body.appendChild(iframe);
+}, "Selection must not be replaced with a new object after document.open()");
+</script>