Breadth FIrst Tree Traversal : Convert live test into Jest test.

Trees/test/BreadthFirstTreeTraversal.test.js

@@ -0,0 +1,27 @@
+import { BinaryTree, Node } from '../BreadthFirstTreeTraversal'
+
+describe('Breadth First Tree Traversal', () => {
+  const binaryTree = new BinaryTree()
+
+  const root = new Node(7)
+  root.left = new Node(5)
+  root.right = new Node(8)
+  root.left.left = new Node(3)
+  root.left.right = new Node(6)
+  root.right.right = new Node(9)
+  binaryTree.root = root
+
+  // Vizualization :
+  //
+  //            7
+  //           / \
+  //          5   8
+  //         / \   \
+  //        3   6   9
+
+  it('Binary tree - Level order traversal', () => {
+    expect(binaryTree.traversal).toStrictEqual([])
+    const traversal = binaryTree.breadthFirst()
+    expect(traversal).toStrictEqual([7, 5, 8, 3, 6, 9])
+  })
+})