Farsight.Common

A .NET 10 library providing shared runtime types and a Roslyn incremental source generator for Farsight-style hosted applications. The generator discovers annotated types and auto-registers services and configuration bindings at compile time, eliminating runtime reflection and manual DI registration. Fully compatible with AOT compilation.

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Features

• Compile-time service registration — Annotated singletons and options are registered via source generation
• Zero runtime reflection — All discovery happens at build time
• AOT compatible — No reflection-based code paths; safe for native AOT publishing
• Strict configuration binding — Unknown configuration keys fail at startup
• Validation support — Data annotations and FluentValidation integration

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🚀 Quick Start

1. Install the Package

dotnet add package Farsight.Common

2. Define Your Configuration

using Farsight.Common;
using System.ComponentModel.DataAnnotations;

[ConfigOption(SectionName = "MyApp")]
public class AppOptions
{
    [Required]
    public string Endpoint { get; set; } = string.Empty;
}

3. Create a Service

using Farsight.Common;

public sealed partial class Worker : Singleton
{
    [Inject]
    private readonly AppOptions _options;

    protected override Task RunAsync(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Running on: {Endpoint}", _options.Endpoint);
        return Task.CompletedTask;
    }
}

4. Wire Up Your Application

using Farsight.Common;
using Farsight.Common.Startup;

var builder = Host.CreateApplicationBuilder(args);
builder.AddApplication<BasicFarsightStartup>();

await builder.Build().RunAsync();

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📋 What Gets Generated

Attribute	What It Does
[ConfigOption]	Binds config section → options class with validation
[ConfigOption<TValidator>]	Adds FluentValidation support
Singleton (base class)	Registers as singleton + generates constructor injection
[Inject]	Auto-wires dependencies into private fields

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🏗️ Application Lifecycle

BasicFarsightStartup orchestrates your Singleton services through three phases:

1. Setup — Parallel preparation work
2. Initialize — Ordered initialization
3. Run — Long-running execution

public sealed partial class MyService : Singleton
{
    protected override Task SetupAsync(CancellationToken ct) 
        => Task.CompletedTask;
    
    protected override Task InitializeAsync(CancellationToken ct) 
        => Task.CompletedTask;
    
    protected override Task RunAsync(CancellationToken ct) 
        => Task.CompletedTask;
}

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🔧 Advanced Configuration

FluentValidation Support

[ConfigOption<MyOptionsValidator>(SectionName = "Features")]
public class MyOptions 
{ 
    public string Value { get; set; } = string.Empty;
}

public class MyOptionsValidator : AbstractValidator<MyOptions>
{
    public MyOptionsValidator() => RuleFor(x => x.Value).NotEmpty();
}

Design-Time Configuration

For EF tooling or design-time scenarios:

builder.AddApplicationOptions(); // Only config, no services

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📦 Requirements

• .NET 10.0+
• The source generator is included automatically

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📝 License

MIT License — see LICENSE for details.