fix: peek() should show the front item of queue

Author: ashokdey

src/_DataStructures_/Queue/Queue.test.js

@@ -12,23 +12,24 @@ describe('Data Structure : Queue', () => {
       queue = new Queue();
     });
 
-    it('Should add() element to a queue', () => {
-      queue.add(5);
-      expect(queue.data).toEqual([5]);
+    it('Should enqueue() element to a queue', () => {
+      queue.enqueue(5);
+      expect(queue.peek()).toEqual([5]);
     });
 
-    it('Should remove() an element from the queue', () => {
-      queue.add(2);
-      queue.add(3);
+    it('Should dequeue() an element from the queue', () => {
+      queue.enqueue(2);
+      queue.enqueue(3);
 
-      expect(queue.remove()).toEqual(2);
-      expect(queue.data).toEqual([3]);
+      expect(queue.dequeue()).toEqual(2);
+      expect(queue.peek()).toEqual(3);
+      expect(queue.size()).toEqual(1);
     });
 
     describe('peek()', () => {
       beforeEach(() => {
-        queue.add(2);
-        queue.add(5);
+        queue.enqueue(2);
+        queue.enqueue(5);
       });
 
       it('Should return the elemet to be removed using peek()', () => {

src/_DataStructures_/Queue/index.js

@@ -17,7 +17,7 @@ class Queue extends SinglyLinkedLists {
   }
 
   peek() {
-    return this.getLast();
+    return this.getFirst();
   }
 
   size() {
@@ -41,7 +41,7 @@ class Queue extends SinglyLinkedLists {
     throw new Error(this.NotAllowed);
   }
 
-  getFirst() {
+  getLast() {
     throw new Error(this.NotAllowed);
   }