fix list delete on the middle

Author: amejiarosario

src/data-structures/hash-maps/hashmap.js

@@ -1,4 +1,5 @@
 const LinkedList = require('../linked-lists/linked-list');
+
 class HashMap {
   /**
    * Initialize array that holds the values. Default is size 16

src/data-structures/hash-maps/hashmap.spec.js

@@ -68,7 +68,7 @@ describe('HashMap Tests', () => {
     let hashMap;
 
     beforeEach(() => {
-      hashMap = new HashMap(2, 0);
+      hashMap = new HashMap(1, 0);
 
       hashMap.set('Pineapple', 'Pen Pineapple Apple Pen');
       hashMap.set('Despacito', 'Luis Fonsi');
@@ -88,10 +88,10 @@ describe('HashMap Tests', () => {
     });
 
     it('should increase load factor and size', () => {
-      expect(hashMap.getLoadFactor()).toBe(4);
+      expect(hashMap.getLoadFactor()).toBe(8);
       expect(hashMap.size).toBe(8);
       hashMap.set('test', 'one');
-      expect(hashMap.getLoadFactor()).toBe(9 / 2);
+      expect(hashMap.getLoadFactor()).toBe(9);
       expect(hashMap.size).toBe(9);
     });
 
@@ -110,18 +110,31 @@ describe('HashMap Tests', () => {
     });
 
     it('should update keys on deletes', () => {
-      hashMap.delete('Pineapple');
-      hashMap.delete('Lean On');
-      hashMap.delete('Hello');
-      hashMap.delete('All About That Bass');
-      hashMap.delete('This Is What You Came For');
+      // expect(hashMap.size).toBe(8);
+      // expect(hashMap.has('Hello')).toBe(true);
+      expect(hashMap.delete('Hello')).toBe(true);
+      // expect(hashMap.has('Hello')).toBe(false);
+      // expect(hashMap.size).toBe(7);
+      expect(hashMap.delete('Lean On')).toBe(true);
+      // expect(hashMap.has('Lean On')).toBe(false);
+      // expect(hashMap.size).toBe(6);
+      expect(hashMap.delete('Pineapple')).toBe(true);
+      // expect(hashMap.has('Pineapple')).toBe(false);
+      // expect(hashMap.size).toBe(5);
+      expect(hashMap.delete('All About That Bass')).toBe(true);
+      expect(hashMap.has('All About That Bass')).toBe(false);
+      // expect(hashMap.size).toBe(4);
+      expect(hashMap.delete('This Is What You Came For')).toBe(true);
+      expect(hashMap.has('This Is What You Came For')).toBe(false);
+      expect(hashMap.size).toBe(3);
 
       expect(hashMap.keys()).toEqual(['Despacito', 'Bailando', 'Dura']);
 
       expect(hashMap.delete('Bailando')).toBe(true);
       expect(hashMap.delete('Bailando')).toBe(false);
       expect(hashMap.get('Bailando')).toBe(undefined);
 
+      expect(hashMap.size).toBe(2);
       expect(hashMap.keys()).toEqual(['Despacito', 'Dura']);
     });
   });

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

@@ -195,6 +195,7 @@ class LinkedList {
       this.removeLast();
     } else if (current) {
       current.previous.next = current.next;
+      current.next.previous = current.previous;
       this.size -= 1;
     }
 

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

@@ -322,7 +322,9 @@ describe('LinkedList Test', () => {
         expect(linkedList.size).toBe(2);
         expect(linkedList.first.value).toMatchObject(a);
         expect(linkedList.first.next.value).toMatchObject(c);
+        expect(linkedList.first.previous).toBe(null);
         expect(linkedList.last.value).toMatchObject(c);
+        expect(linkedList.last.previous.value).toMatchObject(a);
       });
 
       it('should remove last', () => {