Svrooij.EndpointMapper 0.3.2

🚀 Svrooij.EndpointMapper

Stop writing boilerplate. Start building APIs. ⚡

A powerful .NET source generator that eliminates repetitive code when building ASP.NET Core minimal APIs. Write less, ship more, and enjoy not having to write boilerplate code.

Why You'll Love It

✨ Zero Runtime Overhead – All magic happens at compile time, not runtime
🎯 Type-Safe – Full IntelliSense support with generated code
📦 Less Boilerplate – Auto-discover and register endpoints effortlessly
🔍 Smart DTO Mapping – Only select what you need from your database
✅ FluentValidation Integration – Validation filters generated automatically
🛠️ Easy to Use – Minimal setup, maximum productivity

Get Started in Seconds

Install the NuGet package:

dotnet add package Svrooij.EndpointMapper

Done! No configuration needed. The source generator does the rest. ✨

<details> <summary>Or add it manually to your project file</summary>

<ItemGroup>
  <PackageReference Include="Svrooij.EndpointMapper" Version="1.0.0" 
                    OutputItemType="Analyzer" 
                    ReferenceOutputAssembly="false" />
</ItemGroup>

</details>

Features

Being a source generator, this library eliminates boilerplate by generating code at compile time. No reflection, no runtime discovery—just blazing-fast, type-safe endpoint management.

• Endpoint Mapping
• Selective DTO Mapping
• FluentValidation Integration

🎯 Easy Endpoint Mapping

Never write repetitive endpoint registration again. Simply implement IMapEndpoint and watch it get automatically discovered and registered.

public class WeatherEndpoint : IMapEndpoint
{
    public void MapEndpoint(IEndpointRouteBuilder app)
    {
        app.MapGet("/weather", () => "Sunny")
           .WithName("GetWeather")
           .WithOpenApi();
           
        app.MapPost("/weather", (WeatherRequest request) => 
            Results.Ok($"Weather updated to {request.Description}"))
           .WithName("UpdateWeather")
           .WithOpenApi();
    }
}

// In Program.cs - that's it!
app.MapEndpointFromMyApi(); // ✨ Auto-generated extension method

What you get:

• 🔍 Automatic discovery of all IMapEndpoint implementations
• 🏎️ Compile-time code generation (zero runtime cost)
• 📁 Organized, maintainable code structure
• 📦 Project-specific extension methods

💡 Selective DTO Mapping

Stop fetching entire database records just to return a few fields. Generate optimized property selectors at compile time—no reflection, no LINQ expressions. Original idea.

// Your domain model
public class User
{
    public int Id { get; set; }
    public required string Name { get; set; }
    public required string Email { get; set; }
    public string? Address { get; set; }
}

// Your DTO with automatic mapping generation
[Svrooij.EndpointMapper.GenerateSelect(typeof(User))]
public class UserDto
{
    public int Id { get; set; }
    public string? Name { get; set; }
    public string? Email { get; set; }
    public string? Address { get; set; }
}

The magic:

• ✨ Generates two extension methods automatically
• 📊 SelectUserDto(IQueryable<User>, properties) – for Entity Framework queries
• 🔄 SelectUserDto(User, properties) – for object mapping
• 🚀 Pure, optimized code generation (no reflection at runtime)
• 🏍️ Select null for not selected columns, before querying the database.

Real-world example:

// Database query
var userDtos = await dbContext.Users
    .SelectUserDto("Id,Name")  // 🎯 Only fetch these columns!
    .ToListAsync();

Perfect for APIs where clients can request specific fields!

✅ FluentValidation Endpoint Filter

Validation code tends to be verbose and repetitive. Not anymore. Automatically generate endpoint filters for all your AbstractValidator<T> implementations.

public class FluentValidationEndpoint : Svrooij.EndpointMapper.IMapEndpoint
{
    public void MapEndpoint(IEndpointRouteBuilder app)
    {
        app.MapPost("/users", PostNewUserAsync)
           .WithOpenApi()
           .WithTags("Users")
           .AddValidationWithUserDtoValidator(); // ✨ Auto-generated!
    }

    private static async Task<IResult> PostNewUserAsync(UserDto userDto) 
        => Results.Ok($"User {userDto.Name} created!");
}

// Your validator
public class UserDtoValidator : AbstractValidator<UserDto>
{
    public UserDtoValidator()
    {
        RuleFor(x => x.Name)
            .NotEmpty().WithMessage("Name is required")
            .MinimumLength(2).WithMessage("At least 2 characters");
    }
}

What's generated:

• 🛡️ UserDtoValidatorFilter : IEndpointFilter
• 🔧 AddValidationWithUserDtoValidator() extension method

Examples & Samples

Want to see it in action? Check out the complete sample project with:

• 📝 Multiple endpoint examples
• 🔍 Selective DTO mapping usage
• ✅ FluentValidation integration
• 🧪 Full test suite

Roadmap & Contributing

This is an active open-source project! Have ideas? Found a bug? Contributions are welcome!

Feel free to:

• 🐛 Report issues
• 💡 Suggest features
• 🔧 Submit pull requests

License

MIT License – see the LICENSE file for details.

Source Generators inspiration

• Andrew Lock Source Generators series
• Microsoft Docs on Source Generators
• PowerShell Source generator

Happy building! 🎉