Mal.SourceGeneratedDI 2.0.0-pre.3

Mal.SourceGeneratedDI

Source-generated dependency injection with compile-time registrations and runtime composition.

Quick Start

Installation

dotnet add package Mal.SourceGeneratedDI

1. Declare services

using Mal.SourceGeneratedDI;

[Singleton]
public class DatabaseService { }

[Instance]
public class RequestHandler
{
    public RequestHandler(DatabaseService db) { }
}

2. Build and resolve

var container = new DependencyContainerBuilder()
    .AddRegistry(new MyAppGeneratedRegistry()) // auto-generated
    .Build();

var handler = container.Resolve<RequestHandler>();

Migrating from V1

V1 used direct container construction. V2 uses registry-based composition for cross-assembly support.

Before (v1)

var container = new DependencyContainer();
var service = container.Resolve<MyService>();

After (v2)

var container = new DependencyContainerBuilder()
    .AddRegistry(new MyAppGeneratedRegistry())
    .Build();
    
var service = container.Resolve<MyService>();

Key changes:

• Use DependencyContainerBuilder with registries instead of direct container construction
• Manual factories: add via builder or generated registry partial hooks

Features

Lifetime Attributes

• [Singleton] - one instance per container
• [Instance] - new instance per resolution

Advanced Features

• Constructor injection with automatic dependency resolution
• Lazy<T> constructor dependencies
• Generic service mapping attributes
• Assembly-level registration attributes
• Circular dependency detection with dependency chain output
• Cross-assembly composition

Configuration

Cross-Assembly Composition

var builder = new DependencyContainerBuilder()
    .AddRegistry(new CoreLibGeneratedRegistry())
    .AddRegistry(new FeatureLibGeneratedRegistry());
var container = builder.Build();

Manual Registrations (Host-Level)

var container = DependencyContainer.Create(builder =>
{
    builder.AddRegistry(new MyAppGeneratedRegistry());
    builder.Register<IClock>(() => new UtcClock());
});

Manual Registrations (Assembly-Level)

namespace Mal.SourceGeneratedDI;

public sealed partial class MyAppGeneratedRegistry
{
    static partial void AddManualFactories(IServiceRegistry registry)
    {
        registry.AddSingleton(typeof(IClock), _ => new UtcClock());
    }
}

Fallback Provider

var container = new DependencyContainerBuilder()
    .AddRegistry(new MyAppGeneratedRegistry())
    .UseFallback(serviceProvider)
    .Build();

Duplicate Registration Strategy

• Throw (default)
• FirstWins
• LastWins

Packages

• Mal.SourceGeneratedDI - source generator and analyzers
• Mal.SourceGeneratedDI.Abstractions - runtime attributes, contracts, builder, and container

Requirements

.NET Standard 2.0+ target support

License

MIT