Merge pull request careercup#38 from DavidOrchard/javascript-chapter2-question3

gaylemcd · gaylemcd · commit 455bd6adf952 · 2014-05-28T16:33:04.000-07:00
Javascript chapter 2 question 3
diff --git a/javascript/lib/data-structures/chapter-2/2_3.js b/javascript/lib/data-structures/chapter-2/2_3.js
@@ -0,0 +1,12 @@
+module.exports = LinkedList = (function() {
+  var deleteNode = function(node) {
+    if(!node || !node.next) return;
+    var next = node.next;
+    node.data = next.data
+    node.next = next.next;
+  };
+
+  return {
+    deleteNode: deleteNode
+  }
+}());
diff --git a/javascript/test/data-structures/chapter-2/2_3_Spec.js b/javascript/test/data-structures/chapter-2/2_3_Spec.js
@@ -0,0 +1,39 @@
+require('../../test_helper');
+describe(LinkedList, function () {
+  describe('deleteNode)', function () {
+
+  it('runs if 0 length list', function () {
+      var l = new SinglyLinkedList();
+      LinkedList.deleteNode(l, new Node("foo"));
+      expect(l).to.be.not.null;
+    });
+    
+
+    it('deletes 1st item in 2 length list', function () {
+      var l = new SinglyLinkedList();
+      var n = new Node("foo");
+      l.addBottom(n);
+      l.addBottom(new Node("bar"));
+      LinkedList.deleteNode(n);
+      expect(l.head).to.equal(n);
+      expect(l.head.data).to.equal("bar");
+    });
+
+    it('returns 3rd item in 5 length list', function () {
+      var l = new SinglyLinkedList();
+      l.addBottom(new Node("a"));
+      l.addBottom(new Node("b"));
+      var n = new Node("c");
+      l.addBottom(n);
+      l.addBottom(new Node("d"));
+      l.addBottom(new Node("e"));
+      
+      LinkedList.deleteNode(n);
+      expect(l.head).to.be.not.null;
+      expect(l.head.data).to.equal("a");
+      expect(l.head.next.data).to.equal("b");
+      expect(l.head.next.next.data).to.equal("d");
+      expect(l.head.next.next.next.data).to.equal("e");
+    });
+  });
+});
