function foo() { arguments.length = 2; var args = Array.prototype.slice.call(arguments); return bar(args); } function bar(args) { var result = 0; for (var x of args) { result += x; } return result; } var sum = 0; for (var i = 0; i < 100; i++) { sum += foo(1, 2, 3, 4, 5, 6); } assertEq(sum, 300);