Question

i stumbled to the next problem… I have database context:

// For support unit testing... 
public interface IDbContext : IDisposable
{
   IQueryable<Hardware> Hardwares { get; }
   IQueryable<ProviderHardware> ProviderHardwares { get; }
}

// Real DbContext (EF 4.0, Code First)
public class PrimaryDbContext : DbContext, IDbContext
{
   public DbSet<Hardware> Hardwares { get; set; }
   public DbSet<ProviderHardware> ProviderHardwares { get; set; }

   IQueryable<Hardware> IDbContext.Hardwares
     { get { return Hardwares; } }
   IQueryable<ProviderHardware> IDbContext.ProviderHardwares
     { get { return ProviderHardwares; } } 
   ...
}

And i try get all hardwares, which doesnt exists in ProviderHardwares table:

var hardwaresRemoved = db.Hardwares.Where(i => (i.IsAvailable == true) &&
   (db.ProviderHardwares.Count(j => j.Article == i.Article) == 0)).ToList();

If i use PrimaryDbContext strictly such as “PrimaryDbContext db = new PrimaryDbContext();” all work fine. But if i use it implicitly “IDbContext db = new PrimaryDbContext();” that i get an exception:

Unable to create a constant value of type
‘ConfiguratorMvcApplication.DomainModels.ProviderHardware’. Only
primitive types (‘such as Int32, String, and Guid’) are supported in
this context.

Summarize, i can’t replace a DbSet on an IQueryable. And how i can use unit testing in this case? I hope someone have resolved this problem yet…
Thank in advance very much!

Answer 1

I suggest you better keep DbSets and do INTEGRATION TESTING including the database.

Because, although passing a unit test with a mock of a DB could be somewhat usefull, you are going to be better off testing with real database (but it’s not unit testing).

On the ClassInitialize erase the database and/or create the initial data for testing.

If you create an App.config file with a connection string you can have a separate test database, and if you are using EF Code First, you get it for free.

Best regards.