Merge pull request knaxus#148 from ChristieRobson/test/all-words-in-trie

test: add test for all-words-in-tree

Author: ashokdey

src/_DataStructures_/Trees/Trie/all-words-in-trie/all-words-in-trie.test.js

@@ -0,0 +1,61 @@
+const allWordsInTrie = require('./index');
+const Trie = require('../index');
+
+describe('Data Structure : Trie : All Words In Tree', () => {
+  it('Should return all words sorted alphabetically', () => {
+    const words = ['bed', 'ball', 'apple', 'java', 'javascript', 'bed'];
+    const trie = new Trie();
+
+    words.forEach(word => trie.insert(word));
+
+    const result = allWordsInTrie(trie.root);
+
+    const expected = ['apple', 'ball', 'bed', 'bed', 'java', 'javascript'];
+    expect(expected).toEqual(result);
+  });
+
+  it('Should retain duplicates', () => {
+    const words = ['bed', 'bed', 'bed'];
+    const trie = new Trie();
+
+    words.forEach(word => trie.insert(word));
+
+    const result = allWordsInTrie(trie.root);
+    expect(result.length).toBe(3);
+  });
+
+  it('passing an empty array of words returns an empty array', () => {
+    const words = [];
+    const trie = new Trie();
+
+    words.forEach(word => trie.insert(word));
+
+    const result = allWordsInTrie(trie.root);
+    expect(result).toEqual([]);
+  });
+
+  it('passing an empty Trie will throw an error ', () => {
+    const trie = new Trie();
+    expect(() => {
+      allWordsInTrie(trie);
+    }).toThrow('Invalid argument: Root of Trie is required');
+  });
+
+  it('passing an empty array will throw an error ', () => {
+    expect(() => {
+      allWordsInTrie([]);
+    }).toThrow('Invalid argument: Root of Trie is required');
+  });
+
+  it('passing null will throw an error ', () => {
+    expect(() => {
+      allWordsInTrie([]);
+    }).toThrow('Invalid argument: Root of Trie is required');
+  });
+
+  it('passing an array not in a Trie will throw an error ', () => {
+    expect(() => {
+      allWordsInTrie(['bed', 'ball', 'apple']);
+    }).toThrow('Invalid argument: Root of Trie is required');
+  });
+});

src/_DataStructures_/Trees/Trie/all-words-in-trie/index.js

@@ -1,5 +1,6 @@
 // eslint-disable-next-line no-unused-vars
 const Trie = require('../index');
+const TrieNode = require('../Node');
 
 function getAllWords(root, level, word) {
   let result = [];
@@ -30,6 +31,10 @@ function getAllWords(root, level, word) {
 }
 
 function allWordsFromTrie(root) {
+  if (!(root instanceof TrieNode)) {
+    throw new Error('Invalid argument: Root of Trie is required');
+  }
+
   const word = []; // char arr to store a word
   for (let i = 0; i < 26; i += 1) {
     word[i] = null;