Arranging Unit Test using Moq

Question

I've created a method called ListOfPeople and trying to write a Unit Test for it. Currently, I am having trouble setting up the Arrange section of my Unit Test. I can't run it right now because my PeopleId and PersonGroupJobId states Cannot resolve symbol.

Question: How can I test this method successfully?

My Method:

public IEnumerable<Person> ListOfPeople(int personId, int? jobId)
        {
            var people = _unitOfWork.GetRepository<DB.Person>().GetAll()
              .Where(p => p.PeopleGroups.Any(m => m.PeopleId == personId 
                              && m.PersonGroupdJobId == jobId));

            if (!people.Any())
                return new List<Person>();

            var personData = people.Select(p => new Person
            {
                Id = p.PersonId,
                Name = p.PersonName,
                WorkTypeId = p.WorkTypeId,
                PrimaryLanguage = p.PrimaryLanguage,
                PeopleGroups = p.PeopleGroups.ToList()
                  .Select(pp => new PeopleGroup
                  {
                      Id = pp.ProjectPartyId,
                      PeopleId = pp.PeopleId,
                      JobId = pp.PersonGroupJobId ?? 0,
                      AddressId = pp.AddressId
                  })
            }).ToList();

            return personData;
        }

Unit Test:

[TestMethod]
    public void ListOfPeople_peopleExist_returnsList()
    {
        // Arrange
        var people = new List<DB.Person>
        {    
            PeopleId = It.IsAny<int>(),
            PersonGroupdJobId = It.IsAny<int>()
        }; 

        _uowMock
            .Setup(mock => mock.GetRepository<DB.Person>().GetAll())
            .Returns(people.AsQueryable());

        // Act
        var result = _repository.ListOfPeople(It.IsAny<int>(), It.IsAny<int>());

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(2, result.Count());

        _unitOfWork.Verify(mock => mock.Commit(), Times.Never());
        _unitOfWork.Verify(mock => mock.GetRepository<DB.Person>().GetAll(), Times.Once());
    }

Answer 1

You aren't initialising your list properly. You need:

var people = new List<DB.Person>
{
    new DB.Person
    {    
        PeopleId = It.IsAny<int>(),
        PersonGroupdJobId = It.IsAny<int>()
    }
};

Answer 2

You aren't using Moq's It matchers correctly. Matchers are intended for use in Moq's Setup and Verify calls (e.g. see here for example usage)

• In the arrange, you shouldn't use use an It.IsAny when creating fake data. All that will happen with It.IsAny<> is that the values will be assigned default(Type), i.e. zero for Ints etc, which isn't going to be useful.

var people = new List<DB.Person>
 {
   new DB.Person
   {        
       PeopleId = 1234, // Some traceable value and NOT It.IsAny<int>(),
       PersonGroupdJobId = 987,
       ...

• In the act step, you need to invoke the method under test with values which exercise the scenario (again, not just It.IsAny<>):

var result = _repository.ListOfPeople(1234, 567); // Filters matching your test scenario

Also, since the method being tested has at least two concerns, viz applying a filter to the repository, and then mapping out a DB entity to another POCO, you need to provide a complete set of input data so that you can prove that all input fields are mapped to output fields.

If you put all this together, your unit test will look something like:

[Test]
public void ListOfPeople_peopleExist_returnsList()
{
    // Arrange : Generate fake data
    var people = new List<DB.Person>
    {    
        new DB.Person
        {
            PersonId = 123,
            PersonName = "Bob",
            PrimaryLanguage = "French",
            WorkTypeId = 987,
            PeopleGroups = new []
            {
                new DB.PeopleGroup
                {
                    AddressId = 123,
                    PersonGroupJobId = 999,
                    PeopleId = 123, // Match the parent ID
                    ProjectPartyId = 3
                }
            }
        }
    };

    // Your _unitOfWork and _repository mocks seem to be class private fields
    var _unitOfWork = new Mock<IUnitOfWork>();

    _unitOfWork
        .Setup(mock => mock.GetRepository<DB.Person>().GetAll())
        .Returns(people.AsQueryable());

    var _repository = new MyRepo(_unitOfWork.Object);

    // Act
    var result = _repository.ListOfPeople(123, 999);

    // Assert
    Assert.IsNotNull(result);
    Assert.AreEqual(1, result.Count(r => r.Name == "Bob" 
                                         && r.Id == 123 
                                         && r.PeopleGroups.First().Id == 3));
  //... etc - ensure all the fields are mapped 

    _unitOfWork.Verify(mock => mock.Commit(), Times.Never());
    _unitOfWork.Verify(mock => mock.GetRepository<DB.Person>().GetAll(), 
                       Times.Once());
}