Toarnbeike.Results.MinimalApi 1.0.0

Toarnbeike.Results.MinimalApi

Seamlessly return Toarnbeike.Results from your Minimal API endpoints with automatic HTTP response mapping.

Features

• Automatic mapping of Result and Result<TValue> types to IResult using an EndpointFilter
• Built-in mappers for common failures to standardized ProblemDetails responses
• Support for custom mappers to override or extend default behavior
• Fully configurable through dependency injection

Getting started

dotnet add package Toarnbeike.Results.MinimalApi

This package targets .NET 9+ and depends on:

• 
• AspNetCore

Usage

Register result mapping

Add result mappping support to your DI container:

  builder.Services.AddResultMapping();

Apply the endpoint filter

Apply the ResultMappingEndpointFilter to any endpoint that returns a Result or Result<TValue>:

  App.MapGet("customer/{id}", (int id, ICustomerService service) =>
  {
      Result<Customer> result = service.GetById(id);
      return result;
  }).AddEndpointFilter<ResultMappingEndpointFilter>();

Mapping behavior

Custom failures can be mapped by registing your own mappers:

  builder.Services.AddResultMapping(options =>
  {
      options.AddMapper<ConflictFailureMapper>();                           // add single mapper
      options.AddMappersFromAssemblyContaining<ConflictFailureMapper>();    // add all mappers from an assembly
      options.UseFallback<CustomFallbackMapper>();                          // override the default fallback mapper for unmapped failures
  });

  public class ConflictFailureMapper : FailureResultMapper<ConflictFailure>
  {
      public ProblemDetails Map(CustomFailure failure)
      {
          return Problem(failure.Message, statusCode: 409);
      }
  }

Recommended approach: group filter

To avoid repeating .AddEndpointFilter<ResultMappingEndpointFilter>() on every endpoint, you can use the MapResultGroup() extension method to apply the filter to a group of endpoints:

  var group = app.MapResultGroup("/customers");

  group.MapGet("/{id}", (int id, ICustomerService service) =>
  {
    Result<Customer> result = service.GetById(id);
    return result;
  });

Every endpoint in the group will automatically map Result and Result<TValue> types to appropriate HTTP responses.

If you rely on Result mapping for all endpoints in your application, you can create a /api group for all endpoints:

  var endpoints = app.MapResultGroup("/api");