1 files changed, 12 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/semantics/forms/attributes-common-to-form-controls/resources/dirname.js b/testing/web-platform/tests/html/semantics/forms/attributes-common-to-form-controls/resources/dirname.js
new file mode 100644
index 0000000000..f0e97bc301
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/forms/attributes-common-to-form-controls/resources/dirname.js
@@ -0,0 +1,12 @@
+function onIframeLoadedDone(t, cb, selector="iframe") {
+  const iframe = document.querySelector(selector);
+  iframe.addEventListener("load", function() {
+    // The initial about:blank load event can be fired before the form navigation occurs.
+    // See https://github.com/whatwg/html/issues/490 for more information.
+    if(iframe.contentWindow.location.href == "about:blank") { return; }
+
+    const params = new URLSearchParams(iframe.contentWindow.location.search);
+    t.step(() => cb(params))
+    t.done();
+  });
+}