public async Task SignUp_UserNotRegistered_ReturnsOk()
        {
            var registration = new Mock <IRegistration>();

            registration.Setup(register => register.RegisterUser(new RegisterUsers())).ReturnsAsync(true);

            var registrationController = new RegistrationController(registration.Object);

            var result = await registrationController.SignUp(new RegisterUsers());

            var okResult = new OkObjectResult(result);

            Assert.AreEqual(200, okResult.StatusCode);
        }
        public async Task SignUp_UserIsRegistered_ReturnsBadRequest()
        {
            var registration = new Mock <IRegistration>();

            registration.Setup(register => register.RegisterUser(new RegisterUsers())).ReturnsAsync(true);

            var registrationController = new RegistrationController(registration.Object);

            var result = await registrationController.SignUp(new RegisterUsers());

            var badResult = new BadRequestObjectResult(result);

            Assert.AreEqual(400, badResult.StatusCode);
        }