unit testing - Using Moq to mock a repository that returns IQueryable<MyObject>

Question

How to I setup my Moq to return some values and having the tested service select the right one?

IRepository:

public interface IGeographicRepository
{
    IQueryable<Country> GetCountries();
}

Service:

public Country GetCountry(int countryId)
{
    return geographicsRepository.GetCountries()
             .Where(c => c.CountryId == countryId).SingleOrDefault();
}

Test:

    [Test]
    public void Can_Get_Correct_Country()
    {
        //Setup
        geographicsRepository.Setup(x => x.GetCountries()).Returns()
        //No idea what to do here.

        //Call
        var country = geoService.GetCountry(1); 
        //Should return object Country with property CountryName="Jamaica"

        //Assert
        Assert.IsInstanceOf<Country>(country);
        Assert.AreEqual("Jamaica", country.CountryName);
        Assert.AreEqual(1, country.CountryId);
        geographicsRepository.VerifyAll();
    }

I'm basically stuck at the setup.

question from:https://stackoverflow.com/questions/4481465/using-moq-to-mock-a-repository-that-returns-iqueryablemyobject

Answer 1

Couldn't you use AsQueryable()?

List<Country> countries = new List<Country>();
// Add Countries...
IQueryable<Country> queryableCountries = countries.AsQueryable();

geographicsRepository.Setup(x => x.GetCountries()).Returns(queryableCountries);