FQ.Functions

Futeq Core Packages

A modern, minimal, and production-ready foundation for building .NET 9 services and APIs —
designed around Clean Architecture, CQRS, and unified result handling.

This ecosystem includes:

Package	Purpose
FQ.Results	Uniform success/error result handling, HTTP mapping, and problem-details integration
FQ.Cqrs	MediatR pipeline behaviors for CQRS (validation, authorization, idempotency, logging, performance)
FQ.AspNetCore	ASP.NET Core utilities (correlation, idempotency, versioning, result mapping)
FQ.Functions	Azure Functions utilities (correlation, idempotency, exception handling, result writers)
FQ.Mapping	Tiny abstraction over object mapping with first‑class Result<T> support

All libraries target .NET 9 and work with:

• MediatR 13.1+
• Microsoft.Azure.Functions.Worker 2.2+
• ASP.NET Core 9.0+

📦 Installation

dotnet add package FQ.Results
dotnet add package FQ.Cqrs
dotnet add package FQ.AspNetCore
dotnet add package FQ.Functions
dotnet add package FQ.Mapping

🧩 FQ.Results

Provides lightweight primitives for handling outcomes and errors across your entire stack.

Result basics

using FQ.Results;

var ok = Result.Ok();
var user = Result<User>.Ok(new User("alice"));
var notFound = Result.Fail(Error.NotFound("user_not_found", "User does not exist"));

Error factory helpers

var e1 = Error.Validation("email", "Invalid format");
var e2 = Error.Forbidden("no_access", "User has no permission");
var e3 = Error.Conflict("duplicate", "Email already exists");

Mapping to HTTP Problem Details

var shape = e1.ToProblemShape("/api/users/1");

Console.WriteLine(shape.Status);  // 400
Console.WriteLine(shape.Type);    // urn:problem-type:validation

JSON-friendly model

All result and error types are fully serializable with System.Text.Json.

var json = JsonSerializer.Serialize(Result.Fail(Error.NotFound("x", "missing")));

Due to immutability of the record classes, use FQ.Results.JsonResultSerializer for deserialization purposes.

var result = JsonResultSerializer.Deserialize<ResultType>(json, _serializerOptions);

⚙️ FQ.Cqrs

Integrates clean CQRS patterns using MediatR pipeline behaviors and Result semantics.

CQRS Setup

In your Startup or DI registration:

services.AddCqrsUtilities()

Handlers

public sealed record CreateUser(string Email, string Password) : ICommand<Result<Guid>>;

public sealed class CreateUserHandler : IRequestHandler<CreateUser, Result<Guid>>
{
    public async Task<Result<Guid>> Handle(CreateUser cmd, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(cmd.Email))
            return Result<Guid>.Fail(Error.Validation("email", "Email is required"));

        var id = Guid.NewGuid();
        return Result<Guid>.Ok(id);
    }
}

Authorizers

public sealed class CreateUserAuthorizer : IAuthorizer<CreateUser>
{
    public Task<Result> AuthorizeAsync(CreateUser request, CancellationToken ct)
    {
        if (request.Email.EndsWith("@futeq.com"))
            return Task.FromResult(Result.Ok());

        return Task.FromResult(Result.Fail(Error.Forbidden("domain_not_allowed")));
    }
}

Idempotent requests

public sealed record CreateOrder(Guid Id, string Customer)
    : ICommand<Result<Guid>>, IIdempotentRequest
{
    public TimeSpan IdempotencyTtl => TimeSpan.FromMinutes(5);
}

🌐 FQ.AspNetCore

Utilities for ASP.NET Core 9.0 projects — standardized middleware and extensions.

Register services

builder.Services.AddAspNetCoreUtilities();
app.UseAspNetCoreUtilities();

Controller helpers

[HttpPost("users")]
public IActionResult Create([FromBody] CreateUser command)
{
    var result = _mediator.Send(command).Result;
    return result.ToActionResult(this);
}

☁️ FQ.Functions

Azure Functions isolated worker helpers.

Configure

var host = new HostBuilder()
    .ConfigureFunctionsWorkerDefaults(builder =>
    {
        builder.UseFunctionsUtilities();
    })
    .ConfigureServices(services =>
    {
        services.AddFunctionsUtilities();
    })
    .Build();

host.Run();

Usage

public class UsersFunctions
{
    [Function("GetUser")]
    public async Task<HttpResponseData> GetUser(
        [HttpTrigger(AuthorizationLevel.Function, "get", Route = "users/{id}")] HttpRequestData req, string id)
    {
        if (id == "404")
        {
                return await req.WriteResultAsync(Result.Fail(Error.NotFound("user", "Not found")));
        }

        return await req.WriteResultAsync(Result.Ok());
    }
}

✅ Testing

All packages have tests (xUnit + FluentAssertions + NSubstitute).

dotnet test -c Release

🧩 License

MIT © 2025 Futeq