third_party/WebKit/LayoutTests/fast/js/add-to-primitive.html

   1 <p>This page tests that string addition prefers valueOf() over toString() for conversion. If the test passes, you'll see a PASS message below.</p>
   2
   3 <pre id="console"></pre>
   4
   5 <script>
   6 function log(s)
   7 {
   8     document.getElementById("console").appendChild(document.createTextNode(s + "\n"));
   9 }
  10
  11 function shouldBe(a, aDescription, b)
  12 {
  13     if (a === b)
  14         log("PASS: " + aDescription + " should be " + b + " and is.");
  15     else
  16         log("FAIL: " + aDescription + " should be " + b + " but instead is " + a + ".");
  17 }
  18
  19 if (this.testRunner)
  20     testRunner.dumpAsText();
  21
  22 var valueOfIsZero = {
  23     valueOf: function valueOf() { return 0; },
  24     toString: function toString() { return 1; }
  25 };
  26
  27 shouldBe('1' + valueOfIsZero, "'1' + valueOfIsZero", "10");
  28
  29 </script>