Is there an in-memory provider for Entity Framework?

Question

I am unit testing code written against the ADO .NET Entity Framework. I would like to populate an in-memory database with rows, and make sure that my code retrieves them properly.

I can mock the Entity Framework using Rhino Mocks, but that would not be sufficient. I would be telling the query what entities to return to me. This would neither test the where clause nor the .Include() statements. I want to be sure that my where clause matches only the rows I intend, and no others. I want to be sure that I have asked for the entities that I need, and none that I don't.

For example:

class CustomerService {     ObjectQuery<Customer> _customerSource;     public CustomerService(ObjectQuery<Customer> customerSource)     {         _customerSource = customerSource;     }     public Customer GetCustomerById(int customerId)     {         var customers = from c in _customerSource.Include("Order")             where c.CustomerID == customerId             select c;         return customers.FirstOrDefault();     } } 

If I mock the ObjectQuery to return a known customer populated with orders, how do I know that CustomerService has the right where clause and Include? I would rather insert some customer rows and some order rows, then assert that the right customer was selected and the orders are populated.

Answer 1

An InMemory provider is included in EF7 (pre-release).

You can use either the NuGet package, or read about it in the EF repo on GitHub (view source).

Answer 2

The article http://www.codeproject.com/Articles/460175/Two-strategies-for-testing-Entity-Framework-Effort  describes Effort  -Entity Framework provider that runs in memory.

You can still use your DbContext or ObjectContext classes within unit tests, without having to have an actual database.