Basic heap specs. typo in heap.

Author: JakeHP

src/data-structures/heap.js

@@ -47,7 +47,7 @@
    *
    * @public
    * @constructor
-   * @param {Function} cmp Function used for comparition between the elements.
+   * @param {Function} cmp Function used for comparison between the elements.
    */
   exports.Heap = function (cmp) {
     this._heap = [];

test/data-structures/heap.spec.js

@@ -0,0 +1,61 @@
+'use strict';
+
+var mod = require('../../src/data-structures/heap.js');
+var Heap = mod.Heap;
+
+describe('Heap', function () {
+  it('should be a constructor function', function () {
+    expect(typeof Heap).toBe('function');
+  });
+  it('should have default comparison function', function () {
+    var heap = new Heap();
+    expect(typeof heap._cmp).toBe('function');
+  });
+  it('should add an object properly', function () {
+    var heap = new Heap();
+    heap.add(1);
+    expect(heap._heap[0]).toBe(1);
+  });
+  it('should remove an object properly', function () {
+    var heap = new Heap();
+    heap.add(1);
+    var res = heap.extract();
+    expect(res).toBe(1);
+    expect(heap._heap.length).toBe(0);
+  });
+  it('should add multiple nodes properly', function () {
+    var heap = new Heap();
+    heap.add(55);
+    heap.add(11);
+    heap.add(66);
+    expect(heap._heap.indexOf(55)).toBeGreaterThan(-1);
+    expect(heap._heap.indexOf(11)).toBeGreaterThan(-1);
+    expect(heap._heap.indexOf(66)).toBeGreaterThan(-1);
+  });
+  it('should remove multiple nodes properly (max heap)', function () {
+    var heap = new Heap();
+    heap.add(55);
+    heap.add(11);
+    heap.add(66);
+    var res = heap.extract();
+    expect(res).toBe(66);
+    res = heap.extract();
+    expect(res).toBe(55);
+    res = heap.extract();
+    expect(res).toBe(11);
+  });
+  it('should remove multiple nodes properly (min heap)', function () {
+    var heap = new Heap(function (a, b) {
+      return b - a;
+    });
+    heap.add(55);
+    heap.add(11);
+    heap.add(66);
+    var res = heap.extract();
+    expect(res).toBe(11);
+    res = heap.extract();
+    expect(res).toBe(55);
+    res = heap.extract();
+    expect(res).toBe(66);
+  });
+});