diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testLocaleCompare.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testLocaleCompare.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+assertEq("undefined".localeCompare(), 0);
+assertEq("a".localeCompare(), "a".localeCompare("undefined"));
+assertEq("a".localeCompare("b"), -1);
+assertEq("a".localeCompare("b", "en"), -1);
+assertEq("b".localeCompare("a"), 1);
+assertEq("b".localeCompare("a", "en"), 1);
+assertEq("a".localeCompare("a"), 0);
+assertEq("a".localeCompare("a", "en"), 0);