Contributing to LoMapper

January 17, 2026 · View on GitHub

Thank you for your interest in contributing to LoMapper! We welcome bug reports, feature requests, and pull requests.

Getting Started

  1. Fork the repository on GitHub
  2. Clone your fork locally: 
    git clone https://github.com/YOUR_USERNAME/lomapper.git
cd lomapper
  3. Create a branch for your feature or fix: 
    git checkout -b feature/my-awesome-feature

Development Setup

  • .NET 8.0 SDK or later
  • Visual Studio 2022, VS Code with C# Extensions, or JetBrains Rider

Build and test:

dotnet build
dotnet test

Code Guidelines

Style & Conventions

  • Use C# 11+ features (nullable reference types, init properties, etc.)
  • Follow Microsoft C# Coding Conventions
  • Use #pragma directives sparingly and document why
  • Aim for 100% nullable reference type compliance (#nullable enable)

Testing

  • Unit tests for all new features
  • Edge case tests for unusual scenarios
  • Negative tests for error conditions
  • Run benchmarks before/after performance-critical changes
dotnet test
cd benchmarks/LoMapper.Benchmarks
dotnet run -c Release

Commit Messages

  • Use clear, descriptive messages
  • Reference issues: "Fixes #123" or "Relates to #456"
  • Example: feat: add support for required properties in mappings

Documentation

  • Update README.md if adding user-facing features
  • Add XML doc comments to public APIs
  • Include code examples in comments

Pull Request Process

  1. Sync with main before submitting:

    git fetch origin
git rebase origin/main

  2. Push to your fork and create a PR on GitHub

  3. PR Description should:

    • Explain the what and why
    • Reference related issues
    • Include test results or benchmarks
    • Note any breaking changes

  4. CI/CD must pass (build, tests, analyzer checks)

  5. Code review — at least one maintainer approval required

Feature Ideas

We're particularly interested in:

  • 🎯 Performance improvements
  • 🛡️ Better diagnostics and error messages
  • 📚 Additional collection types support (custom, LINQ types)
  • 🔄 Flattening/unflattening support
  • 🎬 Expression projection support

See Issues for the full roadmap.

Reporting Bugs

Use GitHub Issues with:

  • Clear title describing the problem
  • Minimal reproduction code
  • .NET version and OS
  • Expected vs actual behavior
  • Error stack trace if applicable

Example:

Title: Nested mappings with null collections crash generator

Environment:
- LoMapper 0.1.0
- .NET 8.0 / Windows 11
- VS 2022

Steps:
1. Create class with nullable collection property
2. Apply [Mapper] attribute
3. Run build

Error: ArgumentNullException in MappingCodeEmitter.cs:123

Questions?

  • 💬 Start a GitHub Discussion for questions
  • 📧 Reach out to maintainers

Thank you for contributing! 🙏