/js/src/jit-test/tests/basic/testInt32ToId.js

http://github.com/zpao/v8monkey · JavaScript · 35 lines · 23 code · 3 blank · 9 comment · 2 complexity · 3a5ff03d5502b85950536116cd8a03fe MD5 · raw file

  1. function testInt32ToId()
  2. {
  3. // Ensure that a property which is a negative integer that does not fit in a
  4. // jsval is properly detected by the 'in' operator.
  5. var obj = { "-1073741828": 17 };
  6. var index = -1073741819;
  7. var a = [];
  8. for (var i = 0; i < 10; i++)
  9. {
  10. a.push(index in obj);
  11. index--;
  12. }
  13. // Ensure that a property which is a negative integer that does not fit in a
  14. // jsval is properly *not* detected by the 'in' operator. In this case
  15. // wrongly applying INT_TO_JSID to -2147483648 will shift off the sign bit
  16. // (the only bit set in that number) and bitwise-or that value with 1,
  17. // producing jsid(1) -- which actually represents "0", not "-2147483648".
  18. // Thus 'in' will report a "-2147483648" property when none exists, because
  19. // it thinks the request was really whether the object had property "0".
  20. var obj2 = { 0: 17 };
  21. var b = [];
  22. var index = -(1 << 28);
  23. for (var i = 0; i < 10; i++)
  24. {
  25. b.push(index in obj2);
  26. index = index - (1 << 28);
  27. }
  28. return a.join(",") + b.join(",");
  29. }
  30. assertEq(testInt32ToId(),
  31. "false,false,false,false,false,false,false,false,false,true" +
  32. "false,false,false,false,false,false,false,false,false,false");