Testcase for Array sort() compareFn behavior

tests/ecmascript/test-bi-array-proto-sort-comparefn.js

@@ -0,0 +1,83 @@
+/*
+ *  Compare function behavior, specified more concretely in ES6.
+ */
+
+/*===
+true
+true
+false
+1,2,3,4,5,6,7,8,9,10
+1,2,3,4,5,6,7,8,9,10
+1,2,3,4,5,6,7,8,9,10
+1,2,3,4,4,4,5,6,6,7,8,9,10
+===*/
+
+function test() {
+    var compareFnCalled = false;
+    var valueOfCalled = false;
+    var toStringCalled = false;
+    var arr;
+
+    function compareFn(a, b) {
+        compareFnCalled = true;
+        var ret = 0;
+        if (a < b) { ret = -1; }
+        if (a > b) { ret = 1; }
+        return {
+            valueOf: function () { valueOfCalled = true; return ret; },
+            toString: function () { toStringCalled = true; return ret; }
+        };
+    }
+
+    arr = [ 10, 4, 7, 3, 1, 2, 6, 5, 9, 8 ];
+
+    // Compare callback counts and arguments are up to the implementation, but
+    // we know it will be called at least once.  So, check that it gets called
+    // and that the result value is ToNumber() coerced based on both side effects
+    // and final sort result.
+
+    arr.sort(compareFn);
+
+    print(compareFnCalled);
+    print(valueOfCalled);
+    print(toStringCalled);
+    print(arr);
+
+    // ToNumber coercion means strings representing numbers can be returned.
+    arr = [ 10, 4, 7, 3, 1, 2, 6, 5, 9, 8 ];
+    arr.sort(function (a, b) {
+        var ret = '0.0';
+        if (a < b) { ret = '-1000'; }
+        if (a > b) { ret = '0xdeadbeef'; }
+        return ret;
+    });
+    print(arr);
+
+    // Inf and -Inf should be treated like 1 and -1.
+    arr = [ 10, 4, 7, 3, 1, 2, 6, 5, 9, 8 ];
+    arr.sort(function (a, b) {
+        var ret = 0/0;
+        if (a < b) { ret = -1/0; }
+        if (a > b) { ret = 1/0; }
+        return ret;
+    });
+    print(arr);
+
+    // If NaN is returned, it is treated like a +0.  We could return Nan for
+    // every element but that would *not* guarantee a stable sort because
+    // stability is not required (and not provided by current qsort approach).
+    arr = [ 10, 4, 7, 4, 4, 3, 1, 6, 2, 6, 5, 9, 8 ];
+    arr.sort(function (a, b) {
+        var ret = 0/0;
+        if (a < b) { ret = -1; }
+        if (a > b) { ret = 1; }
+        return ret;
+    });
+    print(arr);
+}
+
+try {
+    test();
+} catch (e) {
+    print(e.stack || e);
+}