Obsolete Finally

[mariusz96]

The Finally methods with Func parameters:

public interface IAsyncResponsibilityChain<TParameter, TReturn>
{
    IAsyncResponsibilityChain<TParameter, TReturn> Finally(Func<TParameter, Task<TReturn>> finallyFunc);
}

public interface IResponsibilityChain<TParameter, TReturn>
{
    IResponsibilityChain<TParameter, TReturn> Finally(Func<TParameter, TReturn> finallyFunc);
}

do not support DI. Also they might lead less knowledgeable developers to unintentionally capture DI services as variables in the function body:

.Finally(async (ctx) =>
{
    _dbContext.Logs.Add(new Log { Message = "Failed to process request with id: {ctx.Id}." }); // DbContext captured outside of DI.
    await _dbContext.SaveChangesAsync();
})

So I propose to refactor them into classes:

+   public interface ICancellableAsyncFinally<TParameter, TReturn>
+   {
+       Task<TReturn> Finally(TParameter parameter, CancellationToken cancellationToken);
+   }

+   public interface IAsyncFinally<TParameter, TReturn>
+   {
+       Task<TReturn> Finally(TParameter parameter);
+   }

public interface IAsyncResponsibilityChain<TParameter, TReturn>
{
+   IAsyncResponsibilityChain<TParameter, TReturn> Finally<TFinally>() where TFinally : IAsyncFinally<TParameter, TReturn>;
+   IAsyncResponsibilityChain<TParameter, TReturn> CancellableFinally<TCancellableFinally>() where TCancellableFinally : ICancellableAsyncFinally<TParameter, TReturn>;
+   IAsyncResponsibilityChain<TParameter, TReturn> Finally(Type finallyType);
}

+   public interface IFinally<TParameter, TReturn>
+   {
+       TReturn Finally(TParameter parameter);
+   }

public interface IResponsibilityChain<TParameter, TReturn>
{
+   IResponsibilityChain<TParameter, TReturn> Finally<TFinally>() where TFinally : IFinally<TParameter, TReturn>;
+   IResponsibilityChain<TParameter, TReturn> Finally(Type finallyType);
}

And obsolete overloads that use Func.

This would ensure that the old code still compiles while the new code can use DI and avoid "captured services" pitfall.