// Example of generated unit tests (conceptual)

describe('User Authentication', () => {
    // Assuming test setup with request/response mocks
    const request = require('supertest');
    const app = require('../app'); // Your Express app

    it('should register a new user successfully', async () => {
        const res = await request(app)
            .post('/api/auth/register')
            .send({ email: 'test@example.com', password: 'password123' });
        expect(res.statusCode).toEqual(201);
        expect(res.body).toHaveProperty('message', 'User registered successfully');
    });

    it('should not register a user with an existing email', async () => {
        // ... registration for existing user ...
    });

    it('should login a user successfully', async () => {
        // ... first register a user ...
        const res = await request(app)
            .post('/api/auth/login')
            .send({ email: 'test@example.com', password: 'password123' });
        expect(res.statusCode).toEqual(200);
        expect(res.body).toHaveProperty('token');
    });

    it('should fail login with incorrect password', async () => {
        // ...
    });
});