Added linked list spec.

Author: JakeHP

src/data-structures/linked-list.js

@@ -165,7 +165,7 @@
   };
 
   /**
-   * Check or linked list contains cycle.
+   * Check if linked list contains cycle.
    *
    * @public
    * @method

test/data-structures/linked-list.spec.js

@@ -0,0 +1,140 @@
+'use strict';
+
+var mod = require('../../src/data-structures/linked-list.js');
+var Node = mod.Node;
+var LinkedList = mod.LinkedList;
+
+describe('Node', function () {
+  it('should be a constructor function', function () {
+    expect(typeof Node).toBe('function');
+  });
+  it('should construct properly', function () {
+    var node = new Node("data");
+    expect(node.data).toBe("data");
+    expect(node.next).toBe(null);
+    expect(node.prev).toBe(null);
+  });
+});
+
+describe('Linked List', function () {
+  it('should be a constructor function', function () {
+    expect(typeof LinkedList).toBe('function');
+  });
+  it('should push properly', function () {
+    var linkedList = new LinkedList();
+    linkedList.push(1);
+    linkedList.push(2);
+    linkedList.push(3);
+    linkedList.push(4);
+    linkedList.push(5);
+    expect(linkedList.first.data).toBe(1);
+    expect(linkedList.first.next.data).toBe(2);
+    expect(linkedList.first.next.next.data).toBe(3);
+    expect(linkedList.first.next.next.next.data).toBe(4);
+    expect(linkedList.first.next.next.next.next.data).toBe(5);
+    expect(linkedList.last.data).toBe(5);
+  });
+  it('should pop properly', function () {
+    var linkedList = new LinkedList();
+    linkedList.push(1);
+    linkedList.push(2);
+    linkedList.push(3);
+    linkedList.push(4);
+    linkedList.push(5);
+    expect(linkedList.pop().data).toBe(5);
+    expect(linkedList.pop().data).toBe(4);
+    expect(linkedList.pop().data).toBe(3);
+    expect(linkedList.pop().data).toBe(2);
+    expect(linkedList.pop().data).toBe(1);
+  });
+  it('should shift properly', function () {
+    var linkedList = new LinkedList();
+    linkedList.push(1);
+    linkedList.push(2);
+    linkedList.push(3);
+    linkedList.push(4);
+    linkedList.push(5);
+    expect(linkedList.shift().data).toBe(1);
+    expect(linkedList.shift().data).toBe(2);
+    expect(linkedList.shift().data).toBe(3);
+    expect(linkedList.shift().data).toBe(4);
+    expect(linkedList.shift().data).toBe(5);
+  });
+  it('should reverse properly', function () {
+    var linkedList = new LinkedList();
+    linkedList.push(1);
+    linkedList.push(2);
+    linkedList.push(3);
+    linkedList.push(4);
+    linkedList.push(5);
+    linkedList.reverse();
+    expect(linkedList.shift().data).toBe(5);
+    expect(linkedList.shift().data).toBe(4);
+    expect(linkedList.shift().data).toBe(3);
+    expect(linkedList.shift().data).toBe(2);
+    expect(linkedList.shift().data).toBe(1);
+  });
+  it('should recursive reverse properly', function () {
+    var linkedList = new LinkedList();
+    linkedList.push(1);
+    linkedList.push(2);
+    linkedList.push(3);
+    linkedList.push(4);
+    linkedList.push(5);
+    linkedList.recursiveReverse();
+    expect(linkedList.shift().data).toBe(5);
+    expect(linkedList.shift().data).toBe(4);
+    expect(linkedList.shift().data).toBe(3);
+    expect(linkedList.shift().data).toBe(2);
+    expect(linkedList.shift().data).toBe(1);
+  });
+  it('should unshift properly', function () {
+    var linkedList = new LinkedList();
+    linkedList.push(1);
+    linkedList.push(2);
+    linkedList.push(3);
+    linkedList.push(4);
+    linkedList.push(5);
+    linkedList.unshift(3);
+    expect(linkedList.shift().data).toBe(3);
+    expect(linkedList.shift().data).toBe(1);
+    expect(linkedList.shift().data).toBe(2);
+    expect(linkedList.shift().data).toBe(3);
+    expect(linkedList.shift().data).toBe(4);
+    expect(linkedList.shift().data).toBe(5);
+  });
+  it('should properly check for existing cycle', function () {
+    var linkedList = new LinkedList();
+    var last = new Node(2);
+    var first = new Node(1);
+    last.next = first;
+    last.prev = first;
+    first.next = last;
+    first.prev = last;
+    linkedList.first = first;
+    linkedList.last = last;
+    expect(linkedList.hasCycle()).toBe(true);
+  });
+  it('should properly check for non existing cycle', function () {
+    var linkedList = new LinkedList();
+    linkedList.push(1);
+    linkedList.push(2);
+    linkedList.push(3);
+    linkedList.push(4);
+    linkedList.push(5);
+    expect(linkedList.hasCycle()).toBe(false);
+  });
+  it('should inorder properly', function () {
+    var linkedList = new LinkedList();
+    linkedList.push(1);
+    linkedList.push(2);
+    linkedList.push(3);
+    linkedList.push(4);
+    linkedList.push(5);
+    var pushedValue = 1;
+    function callback(node){
+      expect(node.data).toBe(pushedValue++);
+    }
+    linkedList.inorder(callback);
+  });
+});