Unit testing for Questions router

backend/routers/questions.router.test.js

@@ -0,0 +1,183 @@
+// Mock and import Question model, import question router
+jest.mock('../models/question.model');
+const { Question } = require('../models');
+const questionsRouter = require('./questions.router');
+
+// Create a test app with Express
+const express = require('express');
+const supertest = require('supertest');
+const testapp = express();
+// Allow for body parsing of JSON data
+testapp.use(express.json());
+// Allow for body parsing of HTML data
+testapp.use(express.urlencoded({ extended: false }));
+testapp.use('/api/questions/', questionsRouter);
+const request = supertest(testapp);
+
+describe('Unit tests for questions router', () => {
+  // Clear all mocks after each test
+  afterEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe('READ', () => {
+    // Mock question data
+    const mockQuestions = [
+      {
+        id: 1,
+        questionText: 'What is your favorite color?',
+        htmlName: 'favoriteColor',
+        answers: {
+          answerOneText: 'Red',
+          answerTwoText: 'Blue',
+          answerThreeText: 'Green',
+          answerFourText: 'Yellow',
+        },
+      },
+      {
+        id: 2,
+        questionText: 'What is your favorite food?',
+        htmlName: 'favoriteFood',
+        answers: {
+          answerOneText: 'Pizza',
+          answerTwoText: 'Cheeseburger',
+          answerThreeText: 'Sushi',
+          answerFourText: 'Chicken',
+        },
+      },
+    ];
+
+    it('should return all questions with GET /api/questions', async (done) => {
+      // Mock the Question.find() method
+      Question.find.mockResolvedValue(mockQuestions);
+
+      // Mock the request to the API
+      const response = await request.get('/api/questions');
+
+      // Tests
+      expect(Question.find).toHaveBeenCalled();
+      expect(response.status).toBe(200);
+      expect(response.body).toEqual(mockQuestions);
+
+      // Marks completion of tests
+      done();
+    });
+
+    it('should return 400 status code when there is an error with GET /api/questions', async (done) => {
+      // Mock the error thrown when find method is called
+      const error = new Error('Database error');
+      Question.find.mockRejectedValue(error);
+
+      // Mock console log function
+      const consoleLogSpy = jest.spyOn(console, 'log').mockImplementation(() => {});
+
+      // Mock the request to the API
+      const response = await request.get('/api/questions');
+
+      // Tests
+      expect(Question.find).toHaveBeenCalled();
+      expect(consoleLogSpy).toHaveBeenCalledWith(error);
+      expect(response.status).toBe(400);
+
+      // Clean up and restores original console log function
+      consoleLogSpy.mockRestore();
+      // Marks completion of tests
+      done();
+    });
+
+    it('should return a specific question with GET /api/questions/:id', async (done) => {
+      // Mock the Question.findById() method
+      const mockQuestion = mockQuestions[0];
+      const { id } = mockQuestion;
+      Question.findById.mockResolvedValue(mockQuestion);
+
+      // Mock the request to the API
+      const response = await request.get(`/api/questions/${id}`);
+
+      // Tests
+      expect(Question.findById).toHaveBeenCalledWith(`${id}`);
+      expect(response.status).toBe(200);
+      expect(response.body).toEqual(mockQuestion);
+
+      // Marks completion of tests
+      done();
+    });
+
+    it('should return 400 status code when there is an error with GET /api/questions/:id', async (done) => {
+      // Mock user id
+      const id = mockQuestions[0].id;
+
+      // Mock the error when findById method is called
+      const error = new Error('Database error');
+      Question.findById.mockRejectedValue(error);
+
+      // Mock console log function
+      const consoleLogSpy = jest.spyOn(console, 'log').mockImplementation(() => {});
+
+      // Mock the request to the API
+      const response = await request.get(`/api/questions/${id}`);
+
+      // Tests
+      expect(Question.findById).toHaveBeenCalledWith(`${id}`);
+      expect(consoleLogSpy).toHaveBeenCalledWith(error);
+      expect(response.status).toBe(400);
+
+      // Clean up and restores original console log function
+      consoleLogSpy.mockRestore();
+      // Marks completion of tests
+      done();
+    });
+  });
+
+  describe('CREATE', () => {
+    it('should create a new question with POST /api/questions/', async (done) => {
+      // Mock the Question.create() method
+      const newQuestion = {
+        id: 3,
+        questionText: 'What is your favorite animal?',
+        htmlName: 'favoriteAnimal',
+        answers: {
+          answerOneText: 'Dog',
+          answerTwoText: 'Cat',
+          answerThreeText: 'Bird',
+          answerFourText: 'Fish',
+        },
+      };
+
+      // Mock Question.create method
+      Question.create.mockResolvedValue(newQuestion);
+
+      // Mock the request to the API
+      const response = await request.post('/api/questions/').send(newQuestion);
+
+      // Tests
+      expect(Question.create).toHaveBeenCalledWith(newQuestion);
+      expect(response.status).toBe(201);
+
+      // Marks completion of tests
+      done();
+    });
+
+    it('should return 400 status code when there is an error with POST /api/questions', async (done) => {
+      // Mock the error thrown when create method is called
+      const error = new Error('Database error');
+      Question.create.mockRejectedValue(error);
+
+      // Mock console log function
+      const consoleLogSpy = jest.spyOn(console, 'log').mockImplementation(() => {});
+
+      // Mock the request to the API
+      const response = await request.post('/api/questions');
+
+      // Tests
+      expect(Question.create).toHaveBeenCalled();
+      expect(consoleLogSpy).toHaveBeenCalledWith(error);
+      expect(response.status).toBe(400);
+
+      // Clean up and restores original console log function
+      consoleLogSpy.mockRestore();
+      // Marks completion of tests
+      done();
+    });
+  });
+});