Integrations

Beyond running arity directly, several integrations wire it into version control, CI, and other tooling. Each installs a prebuilt binary, so none of them need a Rust toolchain or an R installation.

For editor and language-server setup, see Editor Setup instead.

GitHub Actions

arity-action installs arity and runs the format and lint checks in CI:

jobs:
  arity:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - uses: jolars/arity-action@v1

By default this runs both arity format --check and arity lint over the whole repository. The inputs:

It also exposes the installed version as the version output. To run only one of the two checks, turn the other off:

- uses: jolars/arity-action@v1
  with:
    path: R
    lint: false

Resolving latest picks the newest release that actually carries an asset for the runner’s platform, rather than the newest release outright, so a release whose binaries are still uploading does not break the job.

pre-commit

arity-pre-commit provides pre-commit hooks. It installs a prebuilt binary wheel from PyPI.

repos:
  - repo: https://github.com/jolars/arity-pre-commit
    # tracks the arity release it installs
    rev: v0.15.0
    hooks:
      # Lint .R files
      - id: arity-lint
      # Format the same files in place
      - id: arity-format

To apply safe autofixes as part of linting, pass the flag through:

      - id: arity-lint
        args: [--fix]

Both hooks run with --force-exclude. pre-commit passes staged files as explicit arguments, and files named explicitly are normally always processed; the flag applies the exclude patterns from your arity.toml to them anyway, so a staged file you have excluded stays excluded. See Configuration for those patterns.

mise-en-place

Arity is in the aqua registry as jolars/arity, so mise can install it through its aqua backend:

mise use aqua:jolars/arity

Or in mise.toml:

[tools]
"aqua:jolars/arity" = "latest"

Replace latest with a released version to pin it.

The same registry entry works with aqua directly:

aqua g -i jolars/arity

dprint

dprint-plugin-arity is a dprint plugin that runs the arity formatter (not the linter) inside dprint, so R files are formatted alongside the rest of a project’s languages. Add it with:

dprint config add jolars/arity

That writes a versioned, checksummed entry into your dprint.json:

{
  "arity": {},
  "plugins": [
    "https://plugins.dprint.dev/jolars/arity-x.x.x.wasm@<checksum>"
  ]
}

Configure it under the arity key:

These mirror the [format] keys in arity.toml, and the plugin’s output is byte-identical to arity format for equivalent settings.

Note that the plugin reads its configuration from dprint.json, not from arity.toml. One setting has no equivalent on the dprint side: the arity CLI discovers whether roxygen comments are markdown by default by reading the package’s DESCRIPTION, but a dprint plugin is a WebAssembly module with no filesystem access and cannot. So a package whose DESCRIPTION sets Roxygen: list(markdown = TRUE) needs roxygenMarkdown set explicitly:

{
  "arity": { "roxygenMarkdown": true }
}

Per-block @md and @noMd tags still take precedence over that default, exactly as they do in the CLI.