“EFSample.EmployeeContext’ does not implement interface member ‘EFSample.IEmployeeContext.Employees’. ‘EFSample.EmployeeContext.Employees’ cannot implement ‘EFSample.IEmployeeContext.Employees’ because it does not have the matching return type of ‘System.Data.Entity.IDbSet”

I know DbSet implements IDbSet because it’s right there in the metadata, so what am I missing?

All the code is copied and pasted and visually checked. I’ve been coding for some time now which makes me feel really stupid, I just can’t see the wood for the trees here.

In short, it seems there is no way to make EF “forget” that I temporarily changed my model and now want to leave it as it was. What is the mechanism by which EF senses that the model has changed? Is there any way to tell EF that NO, I DIDN’T mean to change my model after all, and that in fact no migration is actually required?

List<Department> Departments = new List<Department> { …. anything you want in your “database” };

The<IEmployeeContext>()
.WhenToldTo(x => x.Departments.GetEnumerator())
.Return(Departments.GetEnumerator());

This will cover all of the querying you could want to do on IDbSet Departments

To handle add you would just need to do something like

The<IEmployeeContext>()
.WhenToldTo(x => x.Departments.Add(Param<Department>.IsNotNull))
.Return<Department>(param=>{Departments.Add(param);
return param;
});

If you need to connect other methods like Find/Remove etc, you can easily do that too. Also with machine.fakes it’s possible for you to write this code and have it be shared very trivially see the CurrentTime example on https://github.com/BjRo/Machine.Fakes documentation