import unittest
from app import app

class UserServiceTestCase(unittest.TestCase):
    def setUp(self):
        self.app = app.test_client()
        self.app.testing = True

    def test_get_all_users(self):
        response = self.app.get('/users')
        self.assertEqual(response.status_code, 200)
        self.assertIsInstance(response.json, list)

    def test_get_user_by_id(self):
        response = self.app.get('/users/1')
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.json['id'], '1')

    def test_get_user_not_found(self):
        response = self.app.get('/users/999')
        self.assertEqual(response.status_code, 404)

if __name__ == '__main__':
    unittest.main()