Mocking DbContext.Set()?

Question

We're using EF Code first, and have a data context for our sales database. Additionally, we have a class that sits on top of our data context and does some basic CRUD operations.

For example, we have the following function:

public static T Create<T>(int userId, T entity) where T : class, IAllowCreate
{
    if (entity == null)
        throw new ArgumentNullException("entity");

    using (SalesContext dc = new SalesContext())
    {
         dc.Set<T>().Add(entity);
         dc.SaveChanges();

         return entity;
    }
}

I found an example of how to create fake contexts and IDBset properties. I started implementing that, but I ran in to an issue.

We use dc.Set() quite liberally (as seen above) in our code, as we attempt to create generic CRUD methods. Instead of having a ReadCustomer, ReadContact etc, we would just do Read(). However, dc.Set returns a DbSet, not an IDbSet, so I'm not able to mock that.

Has anyone been able to mock or fake DbContext and still use the Set functionality?

score 11 · Accepted Answer · answered Feb 15 '11 at 17:37

11

interface ISalesContext
{
    IDbSet<T> GetIDbSet<T>();
}

class SalesContext : DbContext, ISalesContext
{
    public IDbSet<T> GetIDbSet<T>()
    {
        return Set<T>();
    }
}

I used a different name, but you can use the new operator if you prefer to hide the regular implementation.

answered Feb 15 '11 at 17:37

Diego Mijelshon

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I started down that road and abandoned it too quickly. In the end I had to add a GetNonTrackedDbSet() as well. – taylonr Feb 15 '11 at 19:22
It's only a one time thing though. Just abstract it as an abstract DbContext that you can reuse later. – Sleeper Smith Mar 17 '11 at 06:11

Mocking DbContext.Set()?

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