IDbAsyncEnumerable not implemented

Question

I am trying to make a FakeDbContext with a FakeDbSet for unit testing.

But I get the following error (see below). I am extending DbSet so normally IDbAsyncEnumerable

Answer 1

I renamed the example test classes from here to remove the word Test since they are useful outside of testing:

• DbAsyncEnumerable
• DbAsyncEnumerator<T>
• DbAsyncQueryProvider<TEntity>

Then I added the extension class below so you can now just do ...

var data = new List<Blog> 
{ 
    new Blog { Name = "BBB" }, 
    new Blog { Name = "ZZZ" }, 
    new Blog { Name = "AAA" }, 
}.AsAsyncQueryable();   // <<== new extension method

This is not only useful in unit tests but also when you want to implement an IQueryable<T> interface that either returns an async database query or in memory data that you can subsequently safely call as query.ToAsyncArray().

public static class AsyncQueryableExtensions
{
    public static IQueryable<TElement> AsAsyncQueryable<TElement>(this IEnumerable<TElement> source)
    {
        return new DbAsyncEnumerable<TElement>(source);
    }

    public static IDbAsyncEnumerable<TElement> AsDbAsyncEnumerable<TElement>(this IEnumerable<TElement> source)
    {
        return new DbAsyncEnumerable<TElement>(source);
    }

    public static EnumerableQuery<TElement> AsAsyncEnumerableQuery<TElement>(this IEnumerable<TElement> source)
    {
        return new DbAsyncEnumerable<TElement>(source);
    }

    public static IQueryable<TElement> AsAsyncQueryable<TElement>(this Expression expression)
    {
        return new DbAsyncEnumerable<TElement>(expression);
    }

    public static IDbAsyncEnumerable<TElement> AsDbAsyncEnumerable<TElement>(this Expression expression)
    {
        return new DbAsyncEnumerable<TElement>(expression);
    }

    public static EnumerableQuery<TElement> AsAsyncEnumerableQuery<TElement>(this Expression expression)
    {
        return new DbAsyncEnumerable<TElement>(expression);
    }
}