Request to multi-target EntityFramework6.csproj and include net6.0

[mpickers]

We have a code base in net6.0 (migrated from net framework 4.8) but still use Entity Framework v6.

We were hoping to use the Specification nuget to update some sections of code, but noticed that Ardalis.Specification.EntityFramework6.csproj only targets framework 4.7.2

EF6 targets NetStandard2.1 so there shouldn't be a reason the Ardalis.Specification.EntityFramework6.csproj can't also target net6.0

The only issue would be AsAsyncEnumerable() would have to throw a NotImplementedException() or NotSupportedException() for the RepositoryBaseOfT EF6 implementation, eg

#if NET6_0_OR_GREATER
    /// <summary>
    /// Finds all entities of <typeparamref name="T" />, that matches the encapsulated query logic of the
    /// <paramref name="specification"/>, from the database.
    /// </summary>
    /// <param name="specification">The encapsulated query logic.</param>
    /// <returns>
    ///  Returns an IAsyncEnumerable<T> which can be enumerated asynchronously.
    /// </returns>
    public virtual IAsyncEnumerable<T> AsAsyncEnumerable(ISpecification<T> specification)
    {
      throw new NotImplementedException();
    }
#endif

However, it still allows others to override it and implement their own version of it if they so desire. eg something like https://github.com/dotnet/reactive/blob/main/Ix.NET/Source/System.Linq.Async/System/Linq/Operators/ToAsyncEnumerable.cs

[fiseni]

Hi @mpickers,

We might do this. There is no need to throw an exception, that method won't exist at all in the EF6 package. It will reference the netstandard2.0 TFM of Ardalis.Specification, and we have excluded this method in the interface for this TFM.

#if NET6_0_OR_GREATER
  IAsyncEnumerable<T> AsAsyncEnumerable(ISpecification<T> specification);
#endif

Probably we can do this change for the next release. We just have to think once again whether we're breaking any consumer.

[fiseni]

Hey @mpickers,

I just tested. We can't target netstandard2.1. Consumers will face runtime issues. For instance, if you consume the libraries from .NET6, and you have the following code (which you must have actually), then you'll face a peculiar issue. Since the base package targets .NET6 the AsAsyncEnumerable method in the interface will be enabled. On the other hand, the EF6 package compiled in .netstandard2.1 won't see it and the repo implementation will compile without it. Hence on runtime, you'll get an exception.

public class Repository<T> : RepositoryBase<T> where T : class
{
    public Repository(TestDbContext dbContext) : base(dbContext)
    {
    }
}

Anyway, we can target NET6 for EF6 package. In that case, indeed we have to throw NotImplementedException.

Are you ok with this?

[mpickers]

@fiseni Yes, that would be perfect, thanks.
Yes, I can see the peculiar happenings and have seen it in other migrations I've done, hence I suggested targeting net6. The netstandard2.1 comment was just stating that EF6 was "able" to be used by net6 projects.