Integrations

How to run rainbow-fmt from the tools around a project: pre-commit, CI, editors (TASKS.md T31–T33).

pre-commit

.pre-commit-hooks.yaml defines two hooks. rainbow-fmt rewrites the staged files (so the commit fails once, with the files reformatted, and goes through on the second try); rainbow-fmt-check only reports:

# .pre-commit-config.yaml
repos:
  - repo: https://gitlab.com/thebjorn/rainbow-fmt
    rev: v0.3.0
    hooks:
      - id: rainbow-fmt

The hooks run on the extensions of the built-in packs. For a plugin pack (say .scm), add its files to the hook:

      - id: rainbow-fmt
        files: \.(py|scm)$
        additional_dependencies: [rainbow-lang-scheme]

GitHub Actions

action.yml is a composite action that installs rainbow-fmt and runs rainbow-fmt check (or diff) on the given paths; the job fails when a file would change or cannot be formatted:

jobs:
  format:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: thebjorn/rainbow-fmt@v0.3.0
        with:
          paths: src tests
          command: diff          # show the changes in the log (default: check)
          version: "==0.3.0"     # a PyPI version specifier (default: the latest)

The action needs the repository mirrored on GitHub to be referenced by uses:; from GitLab CI, or anywhere else, the two lines it runs are enough:

format:
  image: python:3.12-slim
  script:
    - pip install rainbow-fmt
    - rainbow-fmt check --no-cache src tests

--no-cache is not needed for correctness (the cache is keyed on the file's content, options and rainbow-fmt's own version) but saves writing a cache that a fresh CI job will never read.

Editors

rainbow-fmt lsp is a language server for document formatting (lsp.md); the VS Code extension in editors/vscode runs it. Any editor with an LSP client can be pointed at the command directly.