Added search function

src/binary-search-tree.js

@@ -12,15 +12,14 @@ class Node {
   }
 
   /**
-   * @return {Boolean}
+   * @return {boolean}
    */
   isLeaf () {
     return !this.left && !this.right;
   }
 }
 
 /**
- * search()
  * findMin()
  * findMax()
  * preOrder()
@@ -61,4 +60,32 @@ export default class BST {
       searchTree(node, this.root);
     }
   }
+
+  /**
+   * @param  {*} value
+   * @return {(Node | boolean)}
+   */
+  search (value) {
+    if (this.root === null) {
+      return false;
+    }
+
+    let current = this.root;
+
+    while (current !== null) {
+      if (value === current.value) {
+        return current;
+      }
+
+      if (value < current.value) {
+        current = current.left;
+      }
+
+      if (value > current.value) {
+        current = current.right;
+      }
+    }
+
+    return false;
+  }
 };

test/binary-search-tree-test.js

@@ -1,7 +1,7 @@
 'use strict';
 
 import {BST} from '../src/index.js';
-import {generateRandomNumbers} from './helper.js';
+import {generateRandomNumbers, getRandomIntInclusive} from './helper.js';
 
 const expect = require('chai').expect;
 
@@ -27,7 +27,7 @@ function checkIfTreeIsBST (tree) {
     return false;
   };
 
-  return checkSubtree(tree.root);
+  return checkSubtree(tree.root || tree);
 }
 
 describe('Test BST', function () {
@@ -56,4 +56,35 @@ describe('Test BST', function () {
 
     expect(checkIfTreeIsBST(tree)).to.be.true;
   });
+
+  it('test searching tree', function () {
+    let tree = new BST();
+
+    let randomData = generateRandomNumbers(50, 1, 9999);
+    randomData.forEach((value) => {
+      tree.add(value);
+    });
+
+    let randomIndex = getRandomIntInclusive(0, randomData.length - 1);
+    let searchResult = tree.search(randomData[randomIndex]);
+
+    expect(searchResult.value).to.equal(randomData[randomIndex]);
+    expect(checkIfTreeIsBST(searchResult)).to.be.true;
+  });
+
+  it('test searching for non-existent value', function () {
+    let tree = new BST();
+
+    let data = [1, 2, 3, 4, 5];
+    data.forEach((value) => {
+      tree.add(value);
+    });
+
+    expect(tree.search(10)).to.be.false;
+  });
+
+  it('test searching empty tree', function () {
+    let tree = new BST();
+    expect(tree.search(10)).to.be.false;
+  });
 });