1 files changed, 39 insertions, 0 deletions
diff --git a/testing/mochitest/BrowserTestUtils/BrowserTestUtilsParent.sys.mjs b/testing/mochitest/BrowserTestUtils/BrowserTestUtilsParent.sys.mjs
new file mode 100644
index 0000000000..ae8321233a
--- /dev/null
+++ b/testing/mochitest/BrowserTestUtils/BrowserTestUtilsParent.sys.mjs
@@ -0,0 +1,39 @@
+/* vim: set ts=2 sw=2 sts=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+export class BrowserTestUtilsParent extends JSWindowActorParent {
+  receiveMessage(aMessage) {
+    switch (aMessage.name) {
+      case "DOMContentLoaded":
+      case "load": {
+        // Don't dispatch events that came from stale actors.
+        let bc = this.browsingContext;
+        if (
+          (bc.embedderElement && bc.embedderElement.browsingContext != bc) ||
+          !(this.manager && this.manager.isCurrentGlobal)
+        ) {
+          return;
+        }
+
+        let event = new CustomEvent(
+          `BrowserTestUtils:ContentEvent:${aMessage.name}`,
+          {
+            detail: {
+              browsingContext: this.browsingContext,
+              ...aMessage.data,
+            },
+          }
+        );
+
+        let browser = this.browsingContext.top.embedderElement;
+        if (browser) {
+          browser.dispatchEvent(event);
+        }
+
+        break;
+      }
+    }
+  }
+}