diff --git a/testcases/test-builtin-array-proto-sort.js b/testcases/test-builtin-array-proto-sort.js
new file mode 100644
index 00000000..395aa183
--- /dev/null
+++ b/testcases/test-builtin-array-proto-sort.js
@@ -0,0 +1,376 @@
+/*
+ *  Array.prototype.sort() tests.
+ *
+ *  The current implementation is qsort() with a random pivot, which makes
+ *  this test non-deterministic unless the internal randomizer state is
+ *  initialized with a fixed seed.
+ */
+
+function dumpValue(v) {
+    var i, n;
+    var tmp;
+    var t;
+
+    n = v.length;
+    tmp = [];
+    for (i = 0; i < n; i++) {
+        if (v.hasOwnProperty(i)) {
+            t = v[i];
+            if (typeof t === 'function') {
+                tmp.push('function');
+            } else if (typeof t === 'object') {
+                tmp.push('object');
+            } else {
+                tmp.push(String(t));
+            }
+        } else {
+            tmp.push('nonexistent');
+        }
+    }
+
+    return tmp.join(',');
+}
+
+function test(this_value, args) {
+    var t;
+
+    try {
+        t = Array.prototype.sort.apply(this_value, args);
+        print(dumpValue(t));
+    } catch (e) {
+        print(e.name);
+    }
+}
+
+function printDesc(obj, key) {
+    var pd = Object.getOwnPropertyDescriptor(obj, key);
+    if (!pd) {
+        print(key, 'nonexistent');
+        return;
+    }
+
+    print(key,
+          'value=' + pd.value,
+          'writable=' + pd.writable,
+          'enumerable=' + pd.enumerable,
+          'configurable=' + pd.configurable);
+}
+
+/*===
+===*/
+
+print('basic');
+
+function basicTest() {
+    /* Note that all cases without an explicit compare function will sort
+     * elements as strings after ToString() coercion, e.g. 1 and 2 are
+     * compared with string comparison "1" vs "2".  Thus, "1" < "10" < "2".
+     */
+
+    // empty case
+
+    test([], []);
+    test({ length: 0 }, []);
+    test({}, []);
+
+    // one element case
+
+    test([1], []);
+
+    // a few different lengths, in various orders
+
+    test([1,2], []);
+    test([2,1], []);
+    test([1,2,3], []);
+    test([1,3,2], []);
+    test([2,1,3], []);
+    test([2,3,1], []);
+    test([3,1,2], []);
+    test([3,2,1], []);
+
+    // a few different lengths with some equal elements
+
+    test([1,1], []);
+    test([1,1,2], []);
+    test([1,2,1], []);
+    test([2,1,1], []);
+
+    // undefined elements will be pushed to the end, and 'nonexistent' elements
+    // even farther
+
+    obj = [1,2,undefined,3,4,undefined,5,6,undefined,7,8,undefined,9,10];
+    obj.length = 20;
+    test(obj, []);
+
+    // sparse array
+
+    obj = [1,5,10];
+    obj[100] = 2;
+    obj[101] = 7;
+    obj[102] = 13;
+    obj[50] = 12;
+    test(obj, []);
+
+    // elements are compared as strings by default
+
+    test([1,2,3,4,5,6,7,8,9,10], []);
+    test([2,4,6,8,10,1,3,5,7,9], []);
+
+    // explicit sort function for numbers, ascending and descending
+
+    test([1,2,3,4,5,6,7,8,9,10], [ function(a,b) { return a-b; } ]);
+    test([2,4,6,8,10,1,3,5,7,9], [ function(a,b) { return b-a; } ]);
+}
+
+try {
+    basicTest();
+} catch (e) {
+    print(e);
+}
+
+/*===
+===*/
+
+print('exhaustive');
+
+function cloneArray(x) {
+    return x.map(function(x) { return x; });
+}
+
+function makeNonArray(x) {
+    var res = {};
+    var i;
+
+    for (i = 0; i < x.length; i++) {
+        if (x.hasOwnProperty(i)) {
+            res[i] = x[i];
+        }
+    }
+    res.length = x.length;
+
+    return res;
+}
+
+function exhaustiveSortTest(input, make_sparse, make_nonarray) {
+    function f(arr, rem) {
+        var i, n;
+        var new_arr, new_rem;
+        var tmp;
+
+        n = rem.length;
+        if (n == 0) {
+            if (make_sparse) {
+                n = arr.length;
+                arr[10000] = 'foo';
+                delete arr[10000];
+                arr.length = n;
+            } else if (make_nonarray) {
+                arr = makeNonArray(arr);
+            }
+
+            tmp = dumpValue(arr);
+            Array.prototype.sort.call(arr);
+            print(tmp, '--', dumpValue(arr));
+        } else {
+            for (i = 0; i < n; i++) {
+                new_arr = cloneArray(arr);
+                new_rem = cloneArray(rem);
+                new_arr.push(new_rem.splice(i, 1)[0]);
+                f(new_arr, new_rem);
+            }
+        }
+    }
+
+    f([], input);
+}
+
+try {
+    exhaustiveSortTest([1,2,3], false, false);
+    exhaustiveSortTest([1,2,3], true, false);
+    exhaustiveSortTest([1,2,3], false, true);
+    exhaustiveSortTest([1,2,3,3,4,5], false, false);
+    exhaustiveSortTest([1,2,3,3,4,5], true, false);
+    exhaustiveSortTest([1,2,3,3,4,5], false, true);
+} catch (e) {
+    print(e);
+}
+
+/*===
+===*/
+
+// http://en.wikipedia.org/wiki/Linear_congruential_generator#Parameters_in_common_use
+
+print('random strings');
+
+var rnd_x = 123;
+function prng(max) {
+    rnd_x = (rnd_x * 16807) % 0x7fffffff;
+    return rnd_x % max;
+}
+
+function rndString(maxLen) {
+    var len = prng(maxLen);
+    var i;
+    var res = '';
+
+    for (i = 0; i < len; i++) {
+        res += String.fromCharCode(0x41 + prng(26));
+    }
+
+    return res;
+}
+
+function randomStringsTest() {
+    var arr = [];
+    var i;
+    var str1, str2;
+
+    for (i = 0; i < 10000; i++) {
+        arr.push(rndString(8));
+    }
+
+    print(arr);
+
+    arr.sort();
+    str1 = arr.toString();
+    print(str1);
+
+    arr.sort();
+    str2 = arr.toString();
+    print(str1 === str2);
+}
+
+randomStringsTest();
+
+/*===
+===*/
+
+print('attributes');
+
+function attributeTest() {
+    var obj;
+
+    // attributes are kept when both swapped elements exist: two [[Get]]+[[Put]]
+    // pairs are used
+
+    obj = [];
+    Object.defineProperties(obj, {
+        '0': { value: 'foo', writable: true, enumerable: false, configurable: true },
+        '1': { value: 'bar', writable: true, enumerable: true, configurable: true },
+    });
+    printDesc(obj, '0'); printDesc(obj, '1'); printDesc(obj, 'length');
+    obj.sort();
+    printDesc(obj, '0'); printDesc(obj, '1'); printDesc(obj, 'length');
+
+    // same test but make attributes non-configurable; this must not prevent sorting
+    // because writability is sufficient when swapped pairs exist
+
+    obj = [];
+    Object.defineProperties(obj, {
+        '0': { value: 'foo', writable: true, enumerable: false, configurable: false },
+        '1': { value: 'bar', writable: true, enumerable: true, configurable: false },
+    });
+    printDesc(obj, '0'); printDesc(obj, '1'); printDesc(obj, 'length');
+    obj.sort();
+    printDesc(obj, '0'); printDesc(obj, '1'); printDesc(obj, 'length');
+
+    // if only one end of the swapped pair exists, the other is [[Delete]]'d
+    // and [[Put]] will create a property with default [[Put]] attributes, i.e.
+    // writable, configurable, and enumerable
+
+    obj = [];
+    Object.defineProperties(obj, {
+        '1': { value: 'bar', writable: true, enumerable: false, configurable: true },
+    });
+    printDesc(obj, '0'); printDesc(obj, '1'); printDesc(obj, 'length');
+    obj.sort();
+    printDesc(obj, '0'); printDesc(obj, '1'); printDesc(obj, 'length');
+
+    // same test but '1' is non-configurable -> TypeError
+    // the final state of 'obj' is implementation defined: the specification doesn't
+    // mandate whether or not the [[Put]] for '0' should precede the [[Delete]] for '1'.
+
+    obj = [];
+    Object.defineProperties(obj, {
+        '1': { value: 'bar', writable: true, enumerable: false, configurable: false },
+    });
+    printDesc(obj, '0'); printDesc(obj, '1'); printDesc(obj, 'length');
+    obj.sort();
+    printDesc(obj, '0'); printDesc(obj, '1'); printDesc(obj, 'length');
+}
+
+try {
+    attributeTest();
+} catch (e) {
+    print(e);
+}
+
+/*===
+===*/
+
+print('comparefunction');
+
+function compareFunctionTest() {
+    // the default comparison function compares strings with ToString(); verify
+    // its behavior first
+
+    // basic ascending numeric sort
+
+    test([ '1', 5, '3e0', '9.8', { valueOf: function() { return '7' } }],
+         [ function(a,b) { return Number(a) - Number(b); } ]);
+
+    // basic descending numeric sort
+
+    test([ '1', 5, '3e0', '9.8', { valueOf: function() { return '7' } }],
+         [ function(a,b) { return Number(b) - Number(a); } ]);
+
+    // compareFn TypeError for a non-callable compareFn only occurs when
+    // it is about to be called for the first time
+
+   test([1], [ 'non-callable' ]);  // *no* TypeError
+   test([1,2], [ 'non-callable' ]);  // -> TypeError
+   test([1,2], [ {} ]);  // -> TypeError
+   test([1,2], [ { toLocaleString: 'non-callable' } ]);  // -> TypeError
+
+    // compareFn only gets called if both SortCompare() arguments exist
+    // and neither is 'undefined'.  In this test only one element exists
+    // and is not undefined, so no compareFn calls can be made
+
+   obj = [];
+   obj.length = 10;
+   obj[0] = undefined;
+   obj[2] = undefined;
+   obj[3] = 'foo';
+   obj[6] = undefined;
+   obj[7] = undefined;
+   obj[9] = undefined;
+   test(obj, [ function(a,b) { print('should never be called'); } ]);
+}
+
+try {
+    compareFunctionTest();
+} catch (e) {
+    print(e);
+}
+
+/*
+automatic comparefn
+manual comparefn
+
+already ascending
+already descending
+random
+
+sparse array with an inherited index showing through
+-> impl dependent, what does e.g. node do?
+
+non-extensible object -> impl dep
+non-configurable elem (below length) -> impl dep
+non-writable elem (below length) -> impl dep
+accessor elem (below length)
+
+non-configrable elem above length -> NOT impl dep
+non-writable elem (above length) -> NOT impl dep
+accessor elem (above length)
+*/
+