Transformations.Mapping 2.0.0

Transformations.Mapping

A zero-reflection, NativeAOT-ready object mapper using Roslyn source generators.

📖 Overview

Transformations.Mapping completely replaces runtime reflection mappers (like AutoMapper) with compile-time Roslyn Source Generators. By attributing your classes, the compiler generates lightning-fast To{Target}() and From{Target}() extension methods directly into your assemblies footprint.

🚀 Why Transformations.Mapping?

Runtime reflection maps are notoriously slow, difficult to trim, and fundamentally incompatible with NativeAOT workloads. By shifting the work to the compiler, you guarantee zero cold-start overhead, pristine memory allocation profiles, and immediate compile-time errors if your object graphs fall out of sync.

💡 Key Features & Examples

1. Zero-Friction DTO Mapping

Add the [MapTo] attribute to the partial class, and let the generator seamlessly map shared property names.

// 1. Mark your domain class
[MapTo<UserDto>]
public partial class User
{
    public int Id { get; set; }
    public string GlobalName { get; set; }
    
    // Ignore properties you don't want mapped
    [IgnoreMap]
    public string SecretHash { get; set; }
}

// 2. Consume the generated methods (no dependency injection required)
User domainModel = GetUserFromDb();
UserDto dto = domainModel.ToUserDto();     // Auto-generated!
User reconstructed = User.FromUserDto(dto); // Auto-generated!

2. Rename & Align Properties

If the Target DTO has a different property name, map them directly.

public partial class User
{
    // Maps "GlobalName" to the target's "DisplayName" property
    [MapProperty("DisplayName")]
    public string GlobalName { get; set; }
}

🛠 Advanced Usage

The analyzer continuously runs in the background. If the UserDto expects a DateOfBirth property that isn't mapped, the analyzer emits a TXMAP001 warning in your IDE. You can escalate this to a build-breaking error via .editorconfig guaranteeing mappings never quietly fail in production.

📦 Dependencies

• Transformations.Mapping (Attribute definitions)
• Automatically provisions Transformations.Mapping.Generator (Source Generator)

Part of the Transformations ecosystem. Designed for modern .NET 8+.