fix graph issues

Author: amejiarosario

lib/data-structures/graphs/graph.spec.js

@@ -78,8 +78,10 @@ describe('Graph', () => {
     it('should remove edges with falsy values', () => {
       const [a, b] = graph.addEdge(0, false);
       expect(a.adjacents.map(getValue)).toEqual([false]);
+      expect(b.adjacents.map(getValue)).toEqual([]);
       graph.removeEdge(0, false);
       expect(a.adjacents.map(getValue)).toEqual([]);
+      expect(b.adjacents.map(getValue)).toEqual([]);
     });
 
     it('should not create node when removing unexisting target', () => {
@@ -126,9 +128,9 @@ describe('Graph', () => {
   });
 
   describe('remove vertex and update adjacency list', () => {
-    let n1,
-      n2,
-      n4;
+    let n1;
+    let n2;
+    let n4;
 
     beforeEach(() => {
       // 0 -> 1 <- 2
@@ -142,8 +144,11 @@ describe('Graph', () => {
 
     it('should remove nodes from adjacent list', () => {
       expect(n4.getAdjacents().map(getValue)).toEqual([1, 3]);
+      expect(n2.getAdjacents().map(getValue)).toEqual([1]);
+      expect(graph.nodes.has(n1.value)).toBe(true);
       graph.removeVertex(1);
       expect(n4.getAdjacents().map(getValue)).toEqual([3]);
+      expect(graph.nodes.has(n1.value)).toBe(false);
     });
   });
 
@@ -230,14 +235,10 @@ describe('Graph', () => {
   });
 
   describe('with (people) edges on undigraph', () => {
-    let you,
-      mary,
-      barbara;
-
     beforeEach(() => {
       graph = new Graph(Graph.UNDIRECTED);
-      [you] = graph.addEdge('You', 'Mary');
-      [mary, barbara] = graph.addEdge('Mary', 'Barbara');
+      graph.addEdge('You', 'Mary');
+      graph.addEdge('Mary', 'Barbara');
     });
 
     describe('#areConnected', () => {

lib/data-structures/graphs/node.js

@@ -24,13 +24,15 @@ class Node {
    * Runtime: O(n)
    *
    * @param {Node} node
+   * @returns removed node or false if node was not found
    */
   removeAdjacent(node) {
     const index = this.adjacents.indexOf(node);
     if (index > -1) {
       this.adjacents.splice(index, 1);
       return node;
     }
+    return false;
   }
 
   /**

lib/data-structures/graphs/node.spec.js

@@ -15,10 +15,10 @@ describe('Node (Graph)', () => {
   });
 
   describe('#removeAdjacent', () => {
-    let a,
-      b,
-      c,
-      d;
+    let a;
+    let b;
+    let c;
+    let d;
 
     beforeEach(() => {
       a = node;