Contributing

Thanks for considering contributing to multilinguarr.

Development setup

Prerequisites

• Rust 1.88+ (see rust-toolchain.toml)
• ffmpeg/ffprobe (for language detection)
• Docker (for E2E tests)

Getting started

# Clone
git clone https://github.com/dlepaux/multilinguarr.git
cd multilinguarr

# Enable git hooks (fmt + clippy + test on pre-commit)
git config core.hooksPath .githooks

# Run unit tests
cargo test

# Run clippy
cargo clippy --all-targets --features e2e -- -D warnings

# Run E2E tests (requires Docker + test fixtures)
# Generate fixtures first:
mkdir -p tests/media
cd tests/media
bash ../../scripts/generate-fixtures.sh
cd -

cargo test --features e2e --test e2e

Code quality

• cargo fmt before committing
• cargo clippy -- -D warnings must pass with zero warnings
• No #[allow] unless structurally unavoidable (document why)
• Tests for new features and bug fixes

Commit conventions

Conventional commits:

feat(config): add language validation on instance creation
fix(handler): prevent symlink creation for undetermined languages
docs: update readme with docker-compose example
refactor(detection): simplify to ffprobe-only
test(e2e): add upgrade scenario for series

Architecture

Multilinguarr enforces multi-language audio in the *arr media stack. When Radarr/Sonarr downloads a file:

1. Webhook arrives with file path
2. ffprobe detects audio languages
3. Symlinks/hardlinks created in language-specific library directories
4. Jellyfin/Plex sees them as separate libraries per language

Key design decisions:

• ffprobe is the single source of truth for language detection (not arr API metadata)
• Webhook payload provides file paths (no arr API calls on the hot path)
• SQLite for both job queue and configuration persistence
• API-first configuration (no config files to mount)

Pull requests

• One concern per PR
• Include tests
• Update docs if behavior changes
• CI must pass (fmt + clippy + unit tests + E2E)