novalyn

💅 Beautiful Changelogs using Conventional Commits - Rust port of @unjs/changelogen

Status

✨ MVP Complete - Core features implemented with parity to the JavaScript version.

Parity Achieved: This Rust implementation aims for output parity with @unjs/changelogen. Commit classification, version inference, and markdown output should match the JavaScript version exactly. See PARITY_SPEC.md for detailed requirements.

Distribution: Currently available via Cargo. npm package distribution via NAPI-RS is planned for a future release.

See tasks.md for detailed roadmap and implementation status.

Features

• ✅ Conventional Commit Parsing - Supports standard commit message formats
• ✅ Configurable Types - Customize commit types, emojis, and semver impact
• ✅ Multiple Providers - GitHub, GitLab, Bitbucket repository detection
• ✅ Async & Concurrent - Fast I/O with tokio, parallel processing with rayon
• ✅ Parallel Processing - Fast parsing of large commit histories (4x speedup)
• ✅ Author Attribution - Automatic contributor detection and acknowledgment
• ✅ Semantic Versioning - Automatic version bumping based on changes
• ✅ Idempotent Operation - Safe to rerun without duplicating entries
• ✅ Clean Code Quality - No unwrap() outside tests, clippy clean, comprehensive test coverage

Performance

Novalyn leverages Rust's concurrency primitives for exceptional performance:

• Async I/O: Non-blocking file operations with tokio
• Concurrent Config Loading: Parallel loading of multiple config files (2x speedup)
• Parallel Commit Processing: Multi-threaded parsing and classification (4x speedup on 100+ commits)
• Concurrent Rendering: Parallel section rendering (2.5x speedup)
• Batch GitHub API: Concurrent API requests for author resolution (10x speedup)

See CONCURRENCY.md for detailed performance characteristics and tuning options.

Quick Start

# Install from source (cargo publish pending)
git clone https://github.com/nanodelabs/novalyn
cd novalyn
cargo install --path .

# Basic usage
novalyn show                    # Show next version
novalyn generate                # Generate changelog block  
novalyn generate --write        # Update CHANGELOG.md
novalyn release                 # Full release pipeline (tag + changelog)
novalyn --help                  # See all options

Configuration

Create novalyn.toml in your project root:

# Customize commit types
[types.feat]
title = "✨ Features"
semver = "minor"

[types.fix] 
title = "🐛 Bug Fixes"
semver = "patch"

# Scope mapping
[scopeMap]
"ui" = "frontend"
"api" = "backend"

# GitHub token for release syncing
[tokens]
github = "${GITHUB_TOKEN}"

Or use [package.metadata.novalyn] in Cargo.toml.

Differences from JS Version

Intentional Differences

Feature	JavaScript Version	Rust Version	Notes
Configuration	JSON/JS files	TOML files	Rust ecosystem standard
Config location	package.json or .changelogrc	novalyn.toml or Cargo.toml	Cargo integration
Parallel processing	Single-threaded	Optional multi-threaded (rayon)	Performance optimization for large repos
Package distribution	npm	Cargo (npm via NAPI-RS planned)	Native Rust tooling
Binary size	Node.js required (~50MB+)	Static binary (~5MB)	No runtime dependency

Parity Guarantees

These behaviors match the JavaScript version exactly:

• ✅ Commit classification: Type detection, scope parsing, breaking change identification
• ✅ Version inference: Semver rules including pre-1.0 adjustments
• ✅ Markdown output: Format, section ordering, reference linking
• ✅ Filtering rules: Disabled types, chore(deps) handling
• ✅ Contributors: Deduplication, co-author detection, ordering
• ✅ Idempotence: Safe to rerun without duplication

See PARITY_SPEC.md for comprehensive parity documentation and verification strategy.

Development

See CONTRIBUTING.md for detailed contribution guidelines.

Quick Commands

# Using just (recommended)
just check          # Run all checks (format, lint, test)
just test           # Run tests
just lint           # Run clippy
just fmt            # Format code
just coverage       # Generate coverage report (text summary)
just coverage-html  # Generate HTML coverage report and open in browser
just coverage-lcov  # Generate lcov.info for Codecov

# Manual commands
cargo build
cargo test
cargo clippy -- -D warnings
cargo fmt --all

# Coverage with cargo-llvm-cov
cargo install cargo-llvm-cov
cargo llvm-cov --all-features --workspace
cargo llvm-cov --all-features --workspace --html --open

# Run benchmarks
cargo bench

Environment Variables

NOVALYN_PARALLEL_THRESHOLD=50  # Parallel processing threshold (default: 50)
RUST_LOG=debug                     # Enable debug logging
GITHUB_TOKEN=xxx                   # GitHub API token for release sync

Goals

• Parity with JavaScript Version
• Support more than just npm (cargo, go and others, contributions needed!)
• Performance
• Security
• else?

License

MIT - See LICENSE for details

Acknowledgments

This project is a Rust port of @unjs/changelogen by the UnJS team.