Start binaryTree test

binaryTree.js

@@ -0,0 +1,66 @@
+function createBinaryNode(key) {
+  return {
+    key,
+    left: null,
+    right: null,
+    addLeft(leftKey) {
+      const newLeft = createBinaryNode(leftKey)
+      this.left = newLeft
+      return newLeft
+
+    },
+    addRight(rightKey) {
+      const newRight = createBinaryNode(rightKey)
+      this.right = newRight
+      return newRight
+    }
+  }
+}
+
+const TRAVERSALS = {
+  IN_ORDER: (node, visitFn) => {
+    if (node !== null) {
+      TRAVERSALS.IN_ORDER(node.left, visitFn)
+      visitFn(node)
+      TRAVERSALS.IN_ORDER(node.right, visitFn)
+    }
+  },
+  PRE_ORDER: (node, visitFn) => {
+    if (node !== null) {
+      visitFn(node)
+      TRAVERSALS.PRE_ORDER(node.left, visitFn)
+      TRAVERSALS.PRE_ORDER(node.right, visitFn)
+    }
+  },
+  POST_ORDER: (node, visitFn) => {
+    if (node !== null) {
+      TRAVERSALS.POST_ORDER(node.left, visitFn)
+      TRAVERSALS.POST_ORDER(node.right, visitFn)
+      visitFn(node)
+    }
+
+  }
+}
+
+function createBinaryTree(rootKey) {
+  const root = createBinaryNode(rootKey)
+
+  return {
+    root,
+    print(traversalType = 'IN_ORDER') {
+      let result = ''
+
+      const visit = node => {
+        result += result.length === 0
+          ? node.key
+          : ` => ${node.key}`
+      }
+
+      TRAVERSALS[traversalType](this.root, visit)
+
+      return result
+    }
+  }
+}
+
+module.exports = createBinaryTree

tests/binaryTree.test.js

@@ -0,0 +1,17 @@
+const createBinaryTree = require('../binaryTree')
+
+describe('binaryTree', () => {
+  test('should pass sanity check', () => {
+    const tree = createBinaryTree('a')
+    const b = tree.root.addLeft('b')
+    const c = tree.root.addRight('c')
+    const d = b.addLeft('d')
+    const e = b.addRight('e')
+    const f = c.addLeft('f')
+    const g = c.addRight('g')
+    const h = d.addLeft('h')
+    const i = d.addRight('i')
+
+    console.log(tree.print());
+  })
+})

graph.test.js → tests/graph.test.js

@@ -1,4 +1,4 @@
-const createGraph = require('./graph')
+const createGraph = require('../graph')
 
 describe('graph', () => {
   describe('addNode', () => {

linkedList.test.js → tests/linkedList.test.js

@@ -1,4 +1,4 @@
-const createLinkedList = require('./linkedList')
+const createLinkedList = require('../linkedList')
 
 describe('linked list', () => {
   describe('get', () => {

stack.test.js → tests/stack.test.js

@@ -1,4 +1,4 @@
-const createStack = require('./stack')
+const createStack = require('../stack')
 
 const element1 = Symbol()
 const element2 = Symbol()

tree.test.js → tests/tree.test.js

@@ -1,4 +1,4 @@
-const createTree = require('./tree')
+const createTree = require('../tree')
 
 describe('tree', () => {
   test('html tree', () => {