FluentRecordResults

A small Result / Result<T> record type for the result-of-object pattern, with fluent extensions to chain, map, branch on, and unwrap result values. Host-specific adapters (ASP.NET Core, …) ship as separate packages so the core stays framework-agnostic.

Status: pre-release. The library is being extracted from a private project into a standalone package; the API may shift before 1.0 and it is not yet published to NuGet.

Packages

Package	Purpose
FluentRecordResults	Core: Result / Result<T>, Bind, Select, Match, GetOrThrow.
FluentRecordResults.Extensions.AspNetCore	ASP.NET Core adapter: ToActionResult mapping Result → HTTP.

Install only what you need:

dotnet add package FluentRecordResults
dotnet add package FluentRecordResults.Extensions.AspNetCore   # if you're on ASP.NET Core

Requirements

• .NET 10 SDK (the extensions use C# 14 extension members).
• FluentRecordResults.Extensions.AspNetCore additionally requires the Microsoft.AspNetCore.App shared framework.

API at a glance

Core (FluentRecordResults):

Type / Extension	Purpose
Result / Result<T>	Success/failure record with Code and Message; implicit bool
ResultErrorCode	Failure taxonomy (InvalidInput, NotFound, DbException, …)
Bind / BindAsync	Chain operations that themselves return a Result
Select / SelectAsync	Map the carried value, propagating failure
Match / MatchAsync / MatchAndPropagate	Pattern-match style dispatch over success / failure
GetOrThrow	Escape hatch that throws an exception derived from the error code

ASP.NET Core (FluentRecordResults.Extensions.AspNetCore):

Extension	Purpose
ToActionResult	Serialize the Result as the response body, map code → HTTP.

ToActionResult maps error codes to HTTP status as follows:

ResultErrorCode	HTTP status
None (success)	200
InvalidInput	400
NotFound	404
DbException	500
SerializationError	500
Error / unmapped	500

You can override the status code per call: result.ToActionResult(statusCode: 201).

Example

A controller action that validates input, loads a record, transforms it and returns the appropriate HTTP response — without manual if (result.IsFailure) plumbing in between:

using Results;
using Results.Extensions;

[ApiController]
[Route("orders")]
public class OrdersController(IOrderService orders) : ControllerBase
{
    [HttpGet("{id:int}")]
    public async Task<IActionResult> Get(int id) =>
        (await ParseId(id)
            .BindAsync(orders.GetByIdAsync)         // Result<Order>
            .SelectAsync(o => OrderDto.From(o)))    // Result<OrderDto>
            .ToActionResult();

    private static Result<int> ParseId(int id) =>
        id > 0
            ? Result<int>.Success(id)
            : Result<int>.Failure(ResultErrorCode.InvalidInput, "Id must be positive.");
}

For non-controller code, use Match to handle both branches inline:

var label = orderResult.Match(
    onSuccess: o   => $"Order #{o.Id} ({o.Total:C})",
    onFailure: r   => $"[{r.Code}] {r.Message}");

Building from source

dotnet build FluentRecordResults.slnx
dotnet pack  FluentRecordResults.slnx -c Release -o artifacts

License

Released under the MIT License.

Author

Andrés de Miguel — GitHub