MaksIT.Results

HTTP-aware Result / Result<T> for .NET - model success and failure once, then map to ASP.NET Core IActionResult or parse the same wire shape from an HttpResponseMessage.

Target: .NET 10 (net10.0)

Why

Most Result libraries give you success/failure (and sometimes a typed error), then leave HTTP as a second mapping in the controller: domain NotFound -> 404, Conflict -> 409, and so on. That remapping is where APIs drift.

MaksIT.Results uses HTTP status codes as the outcome vocabulary. One type carries success/failure, messages, and a shared classification (NotFound, Conflict, TooManyRequests, ...). The service already decided the status; the controller calls ToActionResult().

That is not "leaking HTTP into the domain." Status codes are a mature taxonomy of outcomes that apply beyond the wire - including desktop, workers, and CLI:

Status idea	Same idea outside the browser
404	entity / file / setting not found
409	concurrent edit / state conflict
401 / 403	not signed in / not allowed
422	validation failed
429	rate limit / throttle
503	dependency down / retry later
202	accepted, still processing

Compared to typical Result libs

	Typical Result lib	MaksIT.Results
Outcome model	Success / Failure (+ custom errors)	Success / Failure + HttpStatusCode
Controller mapping	Invent codes, map again to HTTP	Status already set; ToActionResult()
Failure body	Often ad hoc	RFC 7807 ProblemDetails
Client parse	Rare / out of scope	FromHttpResponseAsync / FromActionResult
Status factories	Usually Ok / Fail (+ a few)	Named 1xx-5xx factories

Bottom line: most Result packages stop at "return from a method." This one is a service <-> API <-> client result model - one contract from domain to wire and back.

Install

dotnet add package MaksIT.Results

Install-Package MaksIT.Results

Quick start

Create results

using MaksIT.Results;

Result ok = Result.Ok("Operation completed");
Result failed = Result.BadRequest("Validation failed");

Result<int> answer = Result<int>.Ok(42, "Answer generated");
Result<UserDto?> missing = Result<UserDto?>.NotFound(null, "Entity not found");

Map between result shapes

Result<int> source = Result<int>.Ok(42, "Value loaded");

Result<string?> asString = source.ToResultOfType(v => v?.ToString());
Result nonGeneric = source.ToResult();

Controllers

using MaksIT.Results;
using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("users")]
public sealed class UsersController : ControllerBase {
  [HttpGet("{id:guid}")]
  public IActionResult Get(Guid id) {
    Result<UserDto?> result = id == Guid.Empty
      ? Result<UserDto?>.BadRequest(null, "Invalid id")
      : Result<UserDto?>.Ok(new UserDto(id, "maks"), "User loaded");

    return result.ToActionResult();
  }
}

public sealed record UserDto(Guid Id, string Name);

HTTP clients

Parse responses produced in the same contract (JSON body, redirect Location, or problem+json):

using HttpResponseMessage response = await http.GetAsync(url);

Result bare = await Result.FromHttpResponseAsync(response);
Result<UserDto> typed = await Result<UserDto>.FromHttpResponseAsync(response);

Or reverse an IActionResult you already built:

IActionResult action = result.ToActionResult();

Result parsed = Result.FromActionResult(action);
Result<UserDto> typed = Result<UserDto>.FromActionResult(action);

ToActionResult() contract

Outcome	Response
Result success	Status code only
Result<T> success, non-null Value	JSON body + status
Result<T> success, redirect status (300-303, 307-308) and non-empty string Value	Redirect; status preserved on RedirectResult
Any failure	ProblemDetails: status, title = "An error occurred", detail = joined Messages, content type application/problem+json

FromActionResult / FromHttpResponseAsync

Wire shape	Result
Success, no body	Success Result / empty Result<T>
Success JSON body	Deserialized into Result<T>.Value
Redirect + Location	Result<string> with that URL and redirect status
application/problem+json (or JSON with detail / title)	Failure; messages from problem details

JSON options

ObjectResult uses the app's JsonSerializerOptions when configured via AddJsonOptions:

builder.Services.AddControllers()
  .AddJsonOptions(options => {
    options.JsonSerializerOptions.DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull;
  });

If none are registered, responses fall back to camel case.

Status code factories

Family	Examples
Informational	Continue, SwitchingProtocols, Processing, ...
Success	Ok, Created, NoContent, ...
Redirection	Found, MovedPermanently, PermanentRedirect, ...
Client error	BadRequest, NotFound, Conflict, TooManyRequests, ...
Server error	InternalServerError, ServiceUnavailable, ...

Use Result.* or Result<T>.* (e.g. Result<MyDto>.Ok(value, "message")).

Contributing

See CONTRIBUTING.md. Changelog: CHANGELOG.md.

License

MIT - Maksym Sadovnychyy (MAKS-IT)

Contact: maksym.sadovnychyy@gmail.com