diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/arrow-functions/precedence-1.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/arrow-functions/precedence-1.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,7 @@
+// || binds tighter than =>.
+
+var f;
+f = a => a || 'nothing';  // f = ((a => a) || 'nothing');
+assertEq(f.length, 1);
+assertEq(f(0), 'nothing');
+assertEq(f(1), 1);