From b1a613e03e13890c19ca7b53b3cd53ab6b826797 Mon Sep 17 00:00:00 2001
From: Cyril Auburtin <cyril.auburtin@gmail.com>
Date: Tue, 29 May 2018 05:13:12 +0200
Subject: [PATCH] Use Map for TrieNode children (#27)

---
 src/data-structures/trie/TrieNode.js          | 20 ++++++++-----------
 .../trie/__test__/TrieNode.test.js            |  2 +-
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/src/data-structures/trie/TrieNode.js b/src/data-structures/trie/TrieNode.js
index 4c267220..345c3362 100644
--- a/src/data-structures/trie/TrieNode.js
+++ b/src/data-structures/trie/TrieNode.js
@@ -2,35 +2,31 @@ export default class TrieNode {
   constructor(character, isCompleteWord = false) {
     this.character = character;
     this.isCompleteWord = isCompleteWord;
-    this.children = {};
+    this.children = new Map();
   }
 
   getChild(character) {
-    if (!Object.prototype.hasOwnProperty.call(this.children, character)) {
-      return null;
-    }
-
-    return this.children[character];
+    return this.children.get(character);
   }
 
   addChild(character, isCompleteWord = false) {
-    if (!this.children[character]) {
-      this.children[character] = new TrieNode(character, isCompleteWord);
+    if (!this.children.has(character)) {
+      this.children.set(character, new TrieNode(character, isCompleteWord));
     }
 
-    return this.children[character];
+    return this.children.get(character);
   }
 
   hasChild(character) {
-    return !!this.children[character];
+    return this.children.has(character);
   }
 
   suggestChildren() {
-    return Object.keys(this.children);
+    return [...this.children.keys()];
   }
 
   toString() {
-    let childrenAsString = Object.keys(this.children).toString();
+    let childrenAsString = this.suggestChildren().toString();
     childrenAsString = childrenAsString ? `:${childrenAsString}` : '';
     const isCompleteString = this.isCompleteWord ? '*' : '';
 
diff --git a/src/data-structures/trie/__test__/TrieNode.test.js b/src/data-structures/trie/__test__/TrieNode.test.js
index d7570b57..943f6a0e 100644
--- a/src/data-structures/trie/__test__/TrieNode.test.js
+++ b/src/data-structures/trie/__test__/TrieNode.test.js
@@ -26,7 +26,7 @@ describe('TrieNode', () => {
 
     expect(trieNode.getChild('a').toString()).toBe('a');
     expect(trieNode.getChild('o').toString()).toBe('o');
-    expect(trieNode.getChild('b')).toBeNull();
+    expect(trieNode.getChild('b')).toBeUndefined();
   });
 
   it('should check if node has specific child', () => {