WebAPI Moq Async EF6 UnitTesting - entity-framework

Question

I'm using Moq to make Mocks for the EF6 Async methods. But something is not working right because i get the following exception:
The source IQueryable doesn't implement IDbAsyncEnumerable{0}. Only
sources that implement IDbAsyncEnumerable can be used for Entity
Framework asynchronous operations. For more details see
http://go.microsoft.com/fwlink/?LinkId=287068.
I have the following code:
UnitTest1.cs
var mockSet = new Mock<DbSet<MyModel>>();
mockSet.As<IDbAsyncEnumerable<MyModel>>()
.Setup(m => m.GetAsyncEnumerator())
.Returns(new TestDbAsyncEnumerator<MyModel>(data.GetEnumerator()));
mockSet.As<IQueryable<MyModel>>()
.Setup(m => m.Provider)
.Returns(new TestDbAsyncQueryProvider<MyModel>(data.Provider));
mockSet.As<IQueryable<MyModel>>().Setup(m => m.Expression).Returns(data.Expression);
mockSet.As<IQueryable<MyModel>>().Setup(m => m.ElementType).Returns(data.ElementType);
mockSet.As<IQueryable<MyModel>>().Setup(m => m.GetEnumerator()).Returns(data.GetEnumerator());
var mockContext = new Mock<PDBContext>();
mockContext.Setup(c => c.GetSet<MyModel>()).Returns(mockSet.Object);
//Test!
var controller = new MyModelController();
controller.MyModelStore = new MyModelStore(mockContext.Object);
var result = await controller.GetBestOppertunity(2) as OkNegotiatedContentResult<List<MyModel>>;
//Result
Assert.IsNotNull(result);
Assert.AreEqual(2, result.Content.Count);
MyModelStore.cs
public async Task<List<MyModel>> GetBestOppertunity(int limit)
{
return await Context.GetSet<MyModel>().OrderByDescending(x => x.StartDate).Take(limit).ToListAsync();
}
I based the code on the following blog to prevent the error from happening: http://msdn.microsoft.com/en-us/data/dn314429
But exactly the error happends that i'm tryging to prevent. The error is explained here: http://msdn.microsoft.com/en-US/data/dn313107
The Error happends in the code: GetBestOppertunity(int limit) in MyModelStore.cs.
The GetSet Method showed there is nothing more than a wrapper to be able to attach unit testing to the Set method.
PDBContext.cs (DatabaseFirst)
public partial class PDBContext : IPDBContext
{
public virtual IDbSet<T> GetSet<T>() where T : class
{
return Set<T>();
}
}
Any Ideas what i'm doing wrong?