1 files changed, 22 insertions, 0 deletions
diff --git a/testing/mochitest/start_desktop.js b/testing/mochitest/start_desktop.js
new file mode 100644
index 0000000000..93d59d935b
--- /dev/null
+++ b/testing/mochitest/start_desktop.js
@@ -0,0 +1,22 @@
+/* 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/. */
+
+// Defined by Marionette.
+/* global __webDriverArguments */
+const flavor = __webDriverArguments[0].flavor;
+const url = __webDriverArguments[0].testUrl;
+
+// eslint-disable-next-line mozilla/use-services
+let wm = Cc["@mozilla.org/appshell/window-mediator;1"].getService(
+  Ci.nsIWindowMediator
+);
+let win = wm.getMostRecentWindow("navigator:browser");
+if (!win) {
+  win = wm.getMostRecentWindow("mail:3pane");
+}
+
+// mochikit's bootstrap.js has set up a listener for this event. It's
+// used so bootstrap.js knows which flavor and url to load.
+let ev = new CustomEvent("mochitest-load", { detail: [flavor, url] });
+win.dispatchEvent(ev);