unit test for heap sort

src/jssort.js

@@ -227,25 +227,28 @@ var jssort = jssort || {};
 
         var N = a.length;
         var N2 = Math.floor(N / 2);
-        for (var k = N2; k <= 1; --k){
-            jss.sink(a, k, N);
+        for (var k = N2; k >= 1; --k){
+            jss.sink(a, k, N, compare);
         }
 
         while (N > 1) {
+
             jss.exchange(a, jss.heapIndex(1), jss.heapIndex(N));
             N--;
-            jss.sink(a, 1, N);
+            jss.sink(a, 1, N, compare);
+
         }
     };
 
-    jss.sink = function(a, k, N) {
+    jss.sink = function(a, k, N, compare) {
         while (k * 2 <= N) {
             var child =  k * 2;
-            if(child < N && jss.less(a[jss.heapIndex(child), jss.heapIndex(child+1)])) {
+            if(child < N && jss.less(a[jss.heapIndex(child)], a[jss.heapIndex(child+1)], compare)) {
                 child++;
             }
-            if(jss.less(a[jss.heapIndex(k)], a[jss.heapIndex(child)])) {
+            if(jss.less(a[jss.heapIndex(k)], a[jss.heapIndex(child)], compare)) {
                 jss.exchange(a, jss.heapIndex(k), jss.heapIndex(child));
+                k = child;
             } else {
                 break;
             }

test/heap-sort-spec.js

@@ -0,0 +1,28 @@
+var expect    = require("chai").expect;
+var jssort = require("../src/jssort");
+
+describe("Heap Sort", function() {
+  describe("Sort Ascendingly", function() {
+
+    it("should sort ascedingly when no compare function is provided", function() {
+
+        var a = [3, 4, 5, 1, 2, 4, 6, 8, 9, 3, 4, 67, 34, 53, 44, 2];
+        jssort.heapSort(a);
+        for(var i = 1; i < a.length; ++i){
+            expect(a[i-1]).not.to.above(a[i]);
+        }
+    });
+
+    it("should sort ascedingly using the provided comparer", function() {
+
+        var a = [[3, 2.3], [4, 3.1], [5, 1.1], [1, 4.2], [2, 4.2], [4, 5.3], [6, 7.4], [8, 5.1], [9, 1.9], [3, 1.2], [4, 3.4], [67, 6.7], [34, 3], [53, 5], [44, 4.2], [2, 0]];
+        jssort.heapSort(a, function(a1, a2){
+                 return a1[1] - a2[1];
+        });
+        for(var i = 1; i < a.length; ++i){
+            expect(a[i-1][1]).not.to.above(a[i][1]);
+        }
+    });
+  });
+
+});