fix(linkedList) fix removeAt

Author: amejiarosario

lib/data-structures/linked-lists/linked-list-1.js

@@ -97,8 +97,16 @@ class LinkedList {
    * @param {any} nth
    */
   removeAt(nth) {
+    if(nth === 0) {
+      return this.removeFirst();
+    }
+
     for (let current = this.first, index = 0; current;  index++, current = current.next) {
       if(index === nth) {
+        if(!current.next) { // if it doesn't have next it means that it is the last
+          return this.removeLast();
+        }
+        current.previous = current.next;
         return current.value;
       }
     }

lib/data-structures/linked-lists/linked-list-2.js

@@ -105,8 +105,17 @@ class LinkedList {
    * @param {any} nth
    */
   removeAt(nth) {
+    if(nth === 0) {
+      return this.removeFirst();
+    }
+
     for (let current = this.first, index = 0; current;  index++, current = current.next) {
       if(index === nth) {
+        if(!current.next) { // if it doesn't have next it means that it is the last
+          return this.removeLast();
+        }
+        current.previous = current.next;
+        this.size--;
         return current.value;
       }
     }

lib/data-structures/linked-lists/linked-list.js

@@ -125,18 +125,29 @@ class LinkedList {
    * @param {any} nth
    */
   removeAt(nth) {
+    if(nth === 0) {
+      return this.removeFirst();
+    }
+
     for (let current = this.first, index = 0; current;  index++, current = current.next) {
       if(index === nth) {
+        if(!current.next) { // if it doesn't have next it means that it is the last
+          return this.removeLast();
+        }
+        current.previous = current.next;
+        this.size--;
         return current.value;
       }
     }
   }
+
 }
 
 // Aliases
 LinkedList.prototype.add = LinkedList.prototype.push = LinkedList.prototype.addLast;
 LinkedList.prototype.remove = LinkedList.prototype.pop = LinkedList.prototype.removeLast;
 LinkedList.prototype.unshift = LinkedList.prototype.addFirst;
 LinkedList.prototype.shift = LinkedList.prototype.removeFirst;
+LinkedList.prototype.search = LinkedList.prototype.contains;
 
 module.exports = LinkedList;

lib/data-structures/linked-lists/linked-list.spec.js

@@ -109,14 +109,27 @@ describe('LinkedList', function () {
 
     describe('#removeAt', () => {
       it('should remove element and return value', () => {
+        expect(linkedList.size).toBe(2);
         expect(linkedList.removeAt(1)).toBe('found');
+        expect(linkedList.size).toBe(1);
+
         expect(linkedList.removeAt(0)).toBe(0);
+        expect(linkedList.size).toBe(0);
       });
 
-      it('should return undefined ', () => {
+      it('should return undefined if not found', () => {
         expect(linkedList.removeAt(2)).toBe(undefined);
         expect(linkedList.removeAt(-2)).toBe(undefined);
       });
+
+      it('should update size, last and first', () => {
+        expect(linkedList.removeAt(0)).toBe(0);
+        expect(linkedList.removeAt(0)).toBe('found');
+        expect(linkedList.removeAt(0)).toBe(undefined);
+        expect(linkedList.size).toBe(0);
+        expect(linkedList.first).toBe(null);
+        expect(linkedList.last).toBe(null);
+      });
     });
   });