Problems with FluentResults.Extensions.AspNetCore

[PUDGE133]

My code:

The problematic part is here:

using FluentResults;
using FluentResults.Extensions.AspNetCore;
using Microsoft.AspNetCore.Mvc;

namespace WebApi
{
    public sealed class PlayerResultProfile : DefaultAspNetCoreResultEndpointProfile
    {
        public override ActionResult TransformFailedResultToActionResult(FailedResultToActionResultTransformationContext context)
        {
            return base.TransformFailedResultToActionResult(context);
        }

        public override ActionResult TransformOkNoValueResultToActionResult(OkResultToActionResultTransformationContext<Result> context)
        {
            return base.TransformOkNoValueResultToActionResult(context);
        }

        public override ActionResult TransformOkValueResultToActionResult<T>(OkResultToActionResultTransformationContext<Result<T>> context)
        {
            return base.TransformOkValueResultToActionResult(context);
        }
    }
}

I get the error "System.MissingMethodException: "Method not found: 'System.Collections.Generic.List`1<FluentResults.IError> FluentResults.ResultBase.get_Errors()'."" every time I get to the Result.Fail method after branching.

For example, I posted a player with the id "str13131414ing". And this operation was successful, because the code passed all the checks and got to the Result.Ok method. However, when I try to create a player with exactly the same id, I do not pass the check and get to the Result.Fail method. As a result:

In principle, the same thing happens in any REST methods when hitting Fail. And I want to note that with any request I hit one of the three overridden methods in the PlayerResultProfile class inherited from DefaultAspNetCoreResultEndpointProfile. I understand that this is how it is intended, but I only get an error with Result.Fail.

Now the most interesting part. If I go to the DefaultAspNetCoreResultEndpointProfile class and completely transfer its contents to my PlayerResultProfile class, all exceptions disappear.

using System.Linq;
using Microsoft.AspNetCore.Mvc;

namespace FluentResults.Extensions.AspNetCore
{
    public class DefaultAspNetCoreResultEndpointProfile : IAspNetCoreResultEndpointProfile
    {
        public virtual ActionResult TransformFailedResultToActionResult(FailedResultToActionResultTransformationContext context)
        {
            var result = context.Result;

            var errorDtos = result.Errors.Select(e => new ErrorDto
                                                      {
                                                          Message = e.Message
                                                      });

            return new BadRequestObjectResult(errorDtos);
        }

        public virtual ActionResult TransformOkNoValueResultToActionResult(OkResultToActionResultTransformationContext<Result> context)
        {
            return new OkResult();
        }

        public virtual ActionResult TransformOkValueResultToActionResult<T>(OkResultToActionResultTransformationContext<Result<T>> context)
        {
            return new OkObjectResult(context.Result.ValueOrDefault);
        }
    }
}

DeepSeek explained that this is due to a version mismatch in your library.

I used your documentation. In WebApi - the project with the ASP.NET part, where the controllers and Program.cs are, I added only NuGet FluentResults.Extensions.AspNetCore. In business logic - the project where the PlayerService class is located, which connects the ASP.NET layer and the layers with validation and the database, I added only NuGet FluentResults.

Also, there is a small question. Why can't DI be added via services?

builder.Services.AddControllers()
    .AddFluentResults(options =>
    {
        options.ResultProfile = new PlayerResultProfile();
    });

[PUDGE133]

Author, do you ever come here?

[ceuser1]

@PUDGE133 I have the same problem... did you find the solution?

[PUDGE133]

@PUDGE133 I have the same problem... did you find the solution?

You need to ignore the default DefaultAspNetCoreResultEndpointProfile implementation and override the methods entirely. It will be better if you inherit (implement) via the IAspNetCoreResultEndpointProfile interface.

using BusinessLogic.FluentResults.Errors;
using FluentResults;
using FluentResults.Extensions.AspNetCore;
using Microsoft.AspNetCore.Mvc;

namespace WebApi.FluentResults
{
    public sealed class ResultProfile : DefaultAspNetCoreResultEndpointProfile
    {
        // We get here when the query result has problems (Result.Fail) and we need to return the corresponding error.
        public override ActionResult TransformFailedResultToActionResult(FailedResultToActionResultTransformationContext context)
        {
            var error = context.Result.Errors.FirstOrDefault();
            return error.GetType().Name switch
            {
                nameof(NotFoundError) => new NotFoundObjectResult(error.Message),
                nameof(BadRequestError) => new BadRequestObjectResult(error.Message),
                _ => new BadRequestObjectResult("For some reason, when converting errors, you got into the \"default\" block."),
            };
        }

        // We get here when the query result is successful. In theory, we should return nothing except the "200" status, however, we get here because of the hacky "WithSuccess" method, or more precisely because of the lack of necessary overloads in the "Result.Ok" method. Therefore, we return the object as if we were in TransformOkValueResultToActionResult.
        public override ActionResult TransformOkNoValueResultToActionResult(OkResultToActionResultTransformationContext<Result> context)
        {
            var success = context.Result.Successes.FirstOrDefault();
            return new OkObjectResult(success.Message);
        }

        // We get here when the query result is successful and we need to return an object.
        public override ActionResult TransformOkValueResultToActionResult<T>(OkResultToActionResultTransformationContext<Result<T>> context)
        {
            return new OkObjectResult(context.Result.Value);
        }
    }
}

[ceuser1]

Thanks 👍

[angusbreno]

While @altmann don't respond, if u want take a look at: https://github.com/ElysiumLabs/FluentResults.Extensions.AspNetCore
This was created to resolve several "features" of the success/error results.