public void CreateUser_Test()
{
var user = new User {
UserName = "******", DisplayName = "Testuser", EmploymentDate = DateTime.Now
};
var userRepositoryMock = new Mock <IRepository <User> >();
userRepositoryMock.Setup(m => m.Insert(user)).Verifiable();
var unitOfWorkMock = new Mock <IUnitOfWork>();
unitOfWorkMock.Setup(m => m.UserRepository).Returns(userRepositoryMock.Object);
IUserSystem sut = new UserSystem(unitOfWorkMock.Object);
//Act
sut.CreateUser(user);
//Assert
userRepositoryMock.Verify(r => r.Insert(user), Times.Once);
unitOfWorkMock.Verify(u => u.SaveChanges(), Times.Once);
}