fixes #3363: modulo operator evaluation order

lib/coffee-script/nodes.js

@@ -3075,7 +3075,7 @@
       return "[].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; }";
     },
     modulo: function() {
-      return "function(a, b) { b = +b; return (a % b + b) % b; }";
+      return "function(a, b) { return (+a % (b = +b) + b) % b; }";
     },
     hasProp: function() {
       return '{}.hasOwnProperty';

src/nodes.coffee

@@ -2194,7 +2194,7 @@ UTILITIES =
   "
 
   modulo: -> """
-    function(a, b) { b = +b; return (a % b + b) % b; }
+    function(a, b) { return (+a % (b = +b) + b) % b; }
   """
 
   # Shortcuts to speed up the lookup time for native functions.

test/operators.coffee

@@ -363,3 +363,10 @@ test "#3361: Modulo operator coerces right operand once", ->
   res = 42 %% valueOf: -> count += 1
   eq 1, count
   eq 0, res
+
+test "#3363: Modulo operator coercing order", ->
+  count = 2
+  a = valueOf: -> count *= 2
+  b = valueOf: -> count += 1
+  eq 4, a %% b
+  eq 5, count