diff -r 000000000000 -r 6474c204b198 testing/mochitest/tests/browser/browser_fail.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/mochitest/tests/browser/browser_fail.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+function test() {
+  ok(false, "fail ok");
+  is(true, false, "fail is");
+  isnot(true, true, "fail isnot");
+  todo(true, "fail todo");
+  todo_is(true, true, "fail todo_is");
+  todo_isnot(true, false, "fail todo_isnot");
+}