How to Test Void Method using xUnit?

Question

I am want to do a unit test of a method that return nothing. I am using xUnit for this. I search in Google but every where I saw methods are returning something.

Here is my code :

My Class :

public class ShopRepository : BaseRepository<ShopInformation>
{
    public ShopRepository(IDbContext dbContext)
        : base(dbContext)
    {
    }

    public override void Update(ShopInformation entity)
    {
        if(GetAll().Any())
            base.Update(entity);
        else
         base.Add(entity);
    }

    public ShopInformation ShopInformation()
    {
        return GetAll().FirstOrDefault();
    }
}

My Test :

    [Fact]
    public void GetAllTest()
    {
        var data = new List<ShopInformation>
        {
            new ShopInformation { Name = "BBB" },
            new ShopInformation { Name = "ZZZ" },
            new ShopInformation { Name = "AAA" },
        }.AsQueryable();

        var mockSet = Mock.Create<DbSet<ShopInformation>>();
        Mock.Arrange(() => ((IEnumerable<ShopInformation>)mockSet).GetEnumerator()).Returns(data.GetEnumerator);

        Mock.Arrange(() => ((IQueryable<ShopInformation>)mockSet).Provider).Returns(data.Provider);

        Mock.Arrange(() => ((IQueryable<ShopInformation>)mockSet).Expression).Returns(data.Expression);
        Mock.Arrange(() => ((IQueryable<ShopInformation>)mockSet).ElementType).Returns(data.ElementType);
        Mock.Arrange(() => ((IQueryable<ShopInformation>)mockSet).GetEnumerator()).Returns(data.GetEnumerator());
        var interDbContext = Mock.Create<IDbContext>();
        interDbContext.Arrange(x => x.Set<ShopInformation>()).Returns(mockSet);

        var companyRepository = new ShopRepository(interDbContext);

        companyRepository.Update(new ShopInformation());

       //???????????????

    }

I need to test Update Method of ShopRepository Class to ensure that base.Update(entity); is call. But don`t understand How to do it.

I am using :

• Visual Studio 2013 Ultimate.
• Just Mock 2013.3.1015
• xUnit 1.9.2

Answer 1

There is 2 possible solutions:

1. If Update method modifies any value from ShopRepository class, you should perform some validation on them.

2. Mock out base.Update method to return "expected" and assert based on that.

Answer 2

Your test is named GetAllTest() , so it probably shouldn't be testing the Update() function.

Best way to do this is to return a bool for if it updated or not.

public bool Update(ShopInformation entity)
{
    if(GetAll().Any())
    {
        base.Update(entity);
        return true; // True because it updated
    }
    else
    {
         base.Add(entity);
         return false; // False because it didn't
    }
}

And then your test can Assert the expected answer.

// ... Setup test code
var hasUpdated = companyRepository.Update(new ShopInformation());
Assert.Equal(true, hasUpdated);

A point to note : If you are using a Repository, you should probably use Save as this will update changes made, but will also add new records if the record does not already exist.