Shim DbContext ctor for Effort unit testing

I'd like to intercept var context = new MyDbContext() to return a different constructor call instead.

The great thing about EFfort is that it let's you set up an easy in-memory database for unit testing.

var connection = Effort.DbConnectionFactory.CreateTransient();
var testContext = new MyDbContext(connection);

But then you'd have to inject that context into your repository.

public FooRepository(MyDbContext context) { _context = context; }

Is it possible to just intercept var context = new MyDbContext() , so that it returns the testContext?

using (var context = new MyDbContext()) {
    // this way, my code isn't polluted with a ctor just for testing
}

(edit: I just realized this isn't actually returning the other ctor call. working on it.)

Figured it out. Simple enough if you know how to do it:

        [TestMethod]
        public void Should_have_a_name_like_this()
        {
            // Arrange
            var connection = Effort.DbConnectionFactory.CreateTransient();
            ShimSolrDbContext.Constructor = context => new SolrDbContext(connection);

            // Act


            // Assert

        }

And as usual, EFfort requires this constructor in the DbContext class:

public class SomeDbContext
{
    public SomeDbContext() : base("name=Prod")
    {
    }

    // EFfort unit testing ctor
    public SomeDbContext(DbConnection connection) : base(connection, contextOwnsConnection: true) {
        Database.SetInitializer<SolrDbContext>(null);
    }
}

But it means the repo is blissfully unaware of the special Transient connection:

public class SomeRepository
{
    public void SomeMethodName()
    {
        using (var context = new SomeDbContext())
        {
            // self-contained in repository, no special params
            // and still calls the special test constructor
        }
    }
}