public async Task ChangeLoginAsync_ShouldReturnErrorWhenExceptionInQuery()
        {
            // ARRANGE
            var mockQuery = new Mock <ITeachersQuery>();

            mockQuery
            .Setup(s => s.ChangeLogin(It.IsAny <int>(), It.IsAny <string>()))
            .ThrowsAsync(new Exception("Mock exception"));

            var mockContextFactory = SetupContextFactory(mockQuery.Object);

            _sut = new TeacherUserService(mockContextFactory.Object);
            var request = new ChangeUserLoginRequest {
                Id = 123, NewLogin = "******"
            };

            // ACT
            var actual = await _sut.ChangeLoginAsync(request);

            //ASSERT
            Assert.Equal("Mock exception", actual.Error.Message);
        }
        public async Task ChangeLoginAsync_ShouldReturnTrue()
        {
            // ARRANGE
            var mockQuery = new Mock <ITeachersQuery>();

            mockQuery
            .Setup(s => s.ChangeLogin(It.IsAny <int>(), It.IsAny <string>()))
            .ReturnsAsync(1);

            var mockContextFactory = SetupContextFactory(mockQuery.Object);

            _sut = new TeacherUserService(mockContextFactory.Object);
            var request = new ChangeUserLoginRequest {
                Id = 123, NewLogin = "******"
            };

            // ACT
            var actual = await _sut.ChangeLoginAsync(request);

            //ASSERT
            Assert.True(actual.Entity);
        }