web-platform-tests · TimothyGu · Aug 17, 2018 · May 3, 2018 · Aug 2, 2018 · Aug 15, 2018
diff --git a/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/no-new-global.window.js b/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/no-new-global.window.js
@@ -0,0 +1,53 @@
+// In an earlier version of the HTML Standard, document open steps created a
+// new JavaScript realm and migrated the existing objects to use the new realm.
+// Test that this no longer happens.
+
+async_test(t => {
+  const frame = document.body.appendChild(document.createElement("iframe"));
+  // Ensure a load event gets dispatched to unblock testharness
+  t.add_cleanup(() => frame.remove());
+  frame.src = "resources/global-variables-frame.html";
+  frame.onload = t.step_func_done(() => {
+    assert_equals(frame.contentWindow.hey, "You", "precondition");
+    frame.contentDocument.open();
+    assert_equals(frame.contentWindow.hey, "You", "actual check");
+  });
+}, "Obtaining a variable from a global whose document had open() invoked");
+
+function testIdentity(desc, frameToObject, frameToConstructor) {
+  async_test(t => {
+    const frame = document.body.appendChild(document.createElement("iframe"));
+    // Ensure a load event gets dispatched to unblock testharness
+    t.add_cleanup(() => frame.remove());
+    frame.src = "/common/blank.html";
+    frame.onload = t.step_func_done(() => {
+      const obj = frameToObject(frame);
+      frame.contentDocument.open();
+      assert_equals(frameToObject(frame), obj);
+    });
+  }, `${desc} maintains object identity through open()`);
+
+  async_test(t => {
+    const frame = document.body.appendChild(document.createElement("iframe"));
+    // Ensure a load event gets dispatched to unblock testharness
+    t.add_cleanup(() => frame.remove());
+    frame.src = "/common/blank.html";
+    frame.onload = t.step_func_done(() => {
+      const obj = frameToObject(frame);
+      const origProto = Object.getPrototypeOf(obj);
+      const origCtor = frameToConstructor(frame);
+      const sym = Symbol();
+      obj[sym] = "foo";
+      frame.contentDocument.open();
+      assert_equals(frameToObject(frame)[sym], "foo");
+      assert_true(frameToObject(frame) instanceof origCtor);
+      assert_equals(Object.getPrototypeOf(frameToObject(frame)), origProto);
+      assert_equals(frameToConstructor(frame), origCtor);
+    });
+  }, `${desc} maintains its prototype and properties through open()`);
+}
+
+testIdentity("Document", frame => frame.contentDocument, frame => frame.contentWindow.Document);
+testIdentity("WindowProxy", frame => frame.contentWindow, frame => frame.contentWindow.Window);
+testIdentity("Location", frame => frame.contentWindow.location, frame => frame.contentWindow.Location);
+testIdentity("Navigator", frame => frame.contentWindow.navigator, frame => frame.contentWindow.Navigator);
diff --git a/...s/dynamic-markup-insertion/opening-the-input-stream/resources/global-variables-frame.html b/...s/dynamic-markup-insertion/opening-the-input-stream/resources/global-variables-frame.html
@@ -0,0 +1,4 @@
+<!doctype html>
+<script>
+hey = "You";
+</script>