Express migration (#80)

* Initial migration

* Cleanup and create migration scripts

* Introduce test suite

* Fix test issues

* Correct CORS issue and update paths

* Update README

backend/tests/unit/middleware/auth.test.js

@@ -0,0 +1,130 @@
+const { requireAuth } = require('../../../middleware/auth');
+const { User } = require('../../../models');
+
+describe('Auth Middleware', () => {
+  let req, res, next;
+
+  beforeEach(() => {
+    req = {
+      path: '/api/tasks',
+      session: {}
+    };
+    res = {
+      status: jest.fn().mockReturnThis(),
+      json: jest.fn()
+    };
+    next = jest.fn();
+  });
+
+  it('should skip authentication for health check', async () => {
+    req.path = '/api/health';
+    
+    await requireAuth(req, res, next);
+    
+    expect(next).toHaveBeenCalled();
+    expect(res.status).not.toHaveBeenCalled();
+  });
+
+  it('should skip authentication for login route', async () => {
+    req.path = '/api/login';
+    
+    await requireAuth(req, res, next);
+    
+    expect(next).toHaveBeenCalled();
+    expect(res.status).not.toHaveBeenCalled();
+  });
+
+  it('should skip authentication for current_user route', async () => {
+    req.path = '/api/current_user';
+    
+    await requireAuth(req, res, next);
+    
+    expect(next).toHaveBeenCalled();
+    expect(res.status).not.toHaveBeenCalled();
+  });
+
+  it('should return 401 if no session', async () => {
+    req.session = null;
+    
+    await requireAuth(req, res, next);
+    
+    expect(res.status).toHaveBeenCalledWith(401);
+    expect(res.json).toHaveBeenCalledWith({ error: 'Authentication required' });
+    expect(next).not.toHaveBeenCalled();
+  });
+
+  it('should return 401 if no userId in session', async () => {
+    req.session = {};
+    
+    await requireAuth(req, res, next);
+    
+    expect(res.status).toHaveBeenCalledWith(401);
+    expect(res.json).toHaveBeenCalledWith({ error: 'Authentication required' });
+    expect(next).not.toHaveBeenCalled();
+  });
+
+  it('should return 401 and destroy session if user not found', async () => {
+    const bcrypt = require('bcrypt');
+    const user = await User.create({
+      email: 'test@example.com',
+      password_digest: await bcrypt.hash('password123', 10)
+    });
+    
+    req.session = {
+      userId: user.id + 1, // Non-existent user ID
+      destroy: jest.fn()
+    };
+    
+    await requireAuth(req, res, next);
+    
+    expect(req.session.destroy).toHaveBeenCalled();
+    expect(res.status).toHaveBeenCalledWith(401);
+    expect(res.json).toHaveBeenCalledWith({ error: 'User not found' });
+    expect(next).not.toHaveBeenCalled();
+  });
+
+  it('should set currentUser and call next for valid session', async () => {
+    const bcrypt = require('bcrypt');
+    const user = await User.create({
+      email: 'test@example.com',
+      password_digest: await bcrypt.hash('password123', 10)
+    });
+    
+    req.session = {
+      userId: user.id
+    };
+    
+    await requireAuth(req, res, next);
+    
+    expect(req.currentUser).toBeDefined();
+    expect(req.currentUser.id).toBe(user.id);
+    expect(req.currentUser.email).toBe(user.email);
+    expect(next).toHaveBeenCalled();
+    expect(res.status).not.toHaveBeenCalled();
+  });
+
+  it('should handle database errors', async () => {
+    // Mock console.error to suppress expected error log in test output
+    const originalConsoleError = console.error;
+    console.error = jest.fn();
+    
+    // Mock User.findByPk to throw an error
+    const originalFindByPk = User.findByPk;
+    User.findByPk = jest.fn().mockRejectedValue(new Error('Database connection error'));
+    
+    req.session = {
+      userId: 123,
+      destroy: jest.fn()
+    };
+    
+    await requireAuth(req, res, next);
+    
+    expect(res.status).toHaveBeenCalledWith(500);
+    expect(res.json).toHaveBeenCalledWith({ error: 'Authentication error' });
+    expect(next).not.toHaveBeenCalled();
+    
+    // Restore original methods
+    User.findByPk = originalFindByPk;
+    console.error = originalConsoleError;
+  });
+});