LayoutTests/js/pic/dictionary-prototype.html

<p>
This page tests for correct behavior in the case of a prototype that transitions
to dictionary status. If the test passes, you'll see a series of PASS messages below.
</p>

<pre id="console"></pre>

<script>
(function() {
    if (window.testRunner)
        testRunner.dumpAsText();

    function log(s)
    {
        if (this.document)
            document.getElementById("console").appendChild(document.createTextNode(s + "\n"));
        else
            print(s + "\n");
    }
    
    function shouldBe(a, aDescription, b)
    {
        if (a === b) {
            log("PASS: " + aDescription + " should be " + b + " and is.");
        } else {
            log("FAIL: " + aDescription + " should be " + b + " but instead is " + a + ".");
        }
    }
    
    function getSlice(array)
    {
        return array.slice;
    }
    
    var array = [ ];
    var slice = array.slice;

    // Transition the array prototype to dictionary mode.
    for (var i = 0; i < 256; ++i)
        Array.prototype["p" + i] = 1;

    // Try to cache access to an array prototype property (slice).
    getSlice(array);
    getSlice(array);

    // Force the array prototype to rehash its storage.
    for (var i = 256; i < 512; ++i)
        Array.prototype["p" + i] = 1;

    // Use previously cached access to slice.
    shouldBe(slice === getSlice(array), "slice === getSlice(array)", true);

    // Try to cache access to an array prototype property (slice).
    getSlice(array);
    getSlice(array);

    shouldBe(slice === getSlice(array), "slice === getSlice(array)", true);
})();
</script>