Source Metadata

frontmatter:
  model: opus
original_description: |
  Specialized agent for ErrorOrX source generator - endpoint generation, parameter binding, Results<> union types, and AOT compatibility

ErrorOrX Generator Specialist

Specialized agent for working with the ErrorOrX source generator.

When to Use

• Modifying endpoint generation logic
• Adding new diagnostics (EOE00XX)
• Changing parameter binding rules
• Extending middleware emission
• AOT compatibility issues
• Results<> union type generation

Repository Context

Path: /Users/ancplua/ErrorOrX Purpose: Source generator converting ErrorOr → ASP.NET Minimal API endpoints Targets: net10.0 (runtime), netstandard2.0 (generator)

Architecture

src/
├── ErrorOrX/                    # Runtime library
│   ├── ErrorOr.cs               # Core type
│   ├── ErrorOr.*.cs             # Extension methods
│   └── ErrorType.cs             # Error categories
└── ErrorOrX.Generators/         # Source generator
    ├── Core/
    │   ├── *.Initialize.cs      # Pipeline setup
    │   ├── *.Extractor.cs       # Syntax → model
    │   ├── *.Emitter.cs         # Model → code
    │   └── *.ParameterBinding.cs # Smart binding
    ├── Models/
    │   ├── EndpointModels.cs    # All data structures
    │   ├── ErrorMapping.cs      # Error → HTTP mapping
    │   └── Enums.cs             # Binding sources
    ├── TypeResolution/
    │   └── WellKnownTypes.cs    # FQN constants
    ├── Validation/
    │   ├── RouteValidator.cs    # Route validation
    │   └── DuplicateRouteDetector.cs
    └── Analyzers/
        └── Descriptors.cs       # All EOE diagnostics

Key Patterns

Minimal Interface Principle

// ✅ Correct - uses only IsError/Errors/Value
if (result.IsError) return ToProblem(result.Errors);
return TypedResults.Ok(result.Value);

// ❌ Avoid - creates dependency on convenience API
return result.Match(v => Ok(v), e => ToProblem(e));

AOT Wrapper Pattern

// Wrapper matches RequestDelegate (HttpContext → Task)
private static async Task Invoke_Ep1(HttpContext ctx)
{
    var __result = await Invoke_Ep1_Core(ctx);
    await __result.ExecuteAsync(ctx);
}

// Core returns typed Results<...> for OpenAPI
private static Task<Results<Ok<T>, NotFound<ProblemDetails>>> Invoke_Ep1_Core(...)

Smart Parameter Binding

Big Picture

• Source of Truth: ANcpLua.Roslyn.Utilities for generator helpers
• Uses: EquatableArray, DiagnosticFlow, TypeSymbolExtensions
• Consumed by: Any project wanting ErrorOr → Minimal API conversion

Build & Test

dotnet build ErrorOrX.slnx
dotnet test --solution ErrorOrX.slnx

Diagnostics (EOE001-EOE054)

Key Files

Ecosystem Context

For cross-repo relationships and source-of-truth locations, invoke:

/ancplua-ecosystem

This skill provides the full dependency hierarchy, what NOT to duplicate from upstream, and version coordination requirements.