/js/src/jit-test/tests/basic/deepForInLoop.js

 1function deepForInLoop() {
 2  // NB: the number of props set in C is arefully tuned to match 8 = 2.
 3  function C(){this.p = 1, this.q = 2}
 4  C.prototype = {p:1, q:2, r:3, s:4, t:5};
 5  var o = new C;
 6  var j = 0;
 7  var a = [];
 8  for (var i in o)
 9    a[j++] = i;
10  return a.join("");
11}
12assertEq(deepForInLoop(), "pqrst");