1 files changed, 19 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/closing-the-input-stream/load-event-after-location-set-during-write.window.js b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/closing-the-input-stream/load-event-after-location-set-during-write.window.js
new file mode 100644
index 0000000000..d5c8469baf
--- /dev/null
+++ b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/closing-the-input-stream/load-event-after-location-set-during-write.window.js
@@ -0,0 +1,19 @@
+// Make sure that the load event for an iframe doesn't fire at the
+// point when a navigation triggered by document.write() starts in it,
+// but rather when that navigation completes.
+
+async_test(t => {
+  const frame = document.body.appendChild(document.createElement("iframe"));
+  const doc = frame.contentDocument;
+  const url = URL.createObjectURL(new Blob(["PASS"], { type: "text/html"}));
+
+  frame.onload = t.step_func_done(() => {
+    assert_equals(frame.contentDocument.body.textContent, "PASS",
+                  "Why is our load event firing before the new document loaded?");
+  });
+
+  doc.open();
+  doc.write(`FAIL<script>location = "${url}"</` + "script>");
+  doc.close();
+}, "Setting location from document.write() call should not trigger load event until that load completes");
+