Arity

A language server, formatter, and linter for R.

Quick start

1. Install the Arity extension.
2. Open an R file (.R, .r, .Rprofile).
3. The extension starts arity lsp automatically.

By default, the extension uses an arity binary that ships inside the extension (one platform-specific VSIX per OS/architecture), falling back to downloading a matching binary from GitHub releases when none is bundled.

Features

• Starts arity lsp automatically when you open R files.
• Formats R code using Arity's deterministic, tidyverse-style formatter.
• Surfaces Arity diagnostics and quick-fix code actions in the editor.
• Registers itself as the default formatter for [r] files.

Commands

• Arity: Restart Server: stops and restarts the Arity language server (re-reads settings and re-resolves the binary). Useful if the LSP gets wedged or after changing settings such as arity.version or arity.executablePath.

Using only some features

The formatter, linter, and language features share one server but can be turned off independently, so you can adopt just the parts you want:

• arity.formatting.enable: use Arity as a formatter.
• arity.diagnostics.enable: show Arity diagnostics (the linter).
• arity.languageFeatures.enable: hover, completion, navigation, symbols, rename (including source() path updates when you move a file or folder), code actions, semantic tokens, and the rest.

All three default to true. They are client-side gates, so the server keeps running and the toggles take effect without a restart or reinstall. For a formatter-only setup, turn off the other two:

{
  "arity.diagnostics.enable": false,
  "arity.languageFeatures.enable": false
}

Turning off arity.diagnostics.enable this way suppresses every diagnostic, including the syntax/parse errors that an arity.toml [lint] selection cannot silence. The arity.toml route stays the right tool when you want to keep parse errors but mute specific lint rules across every editor and the CLI.

Binary installation

By default, the extension uses an arity binary that ships inside the extension itself (one platform-specific VSIX per OS/architecture). No download, no GitHub round-trip, and the language server starts on first activation even on restricted or offline networks. Behavior is controlled by arity.executableStrategy:

• bundled (default): use the binary that ships inside the extension. If you're on a platform without a platform-specific build (or you've installed the universal VSIX), the extension falls back to downloading a matching binary from GitHub releases.
• environment: look for arity on the system PATH.
• path: use the binary at arity.executablePath.

If you set arity.version or arity.releaseTag explicitly, the bundled binary is skipped and the requested version is downloaded from GitHub. When arity.version is latest, the extension selects the most recent stable release that contains a matching platform asset.

Common setup examples

Use a local binary at a fixed path:

{
  "arity.executableStrategy": "path",
  "arity.executablePath": "/usr/local/bin/arity"
}

Use whatever arity is on your PATH:

{
  "arity.executableStrategy": "environment"
}

Pin to a specific release:

{
  "arity.version": "0.2.0",
  "arity.githubRepo": "jolars/arity"
}

Use arity.releaseTag only if you need an exact tag override:

{
  "arity.releaseTag": "v0.2.0"
}

Requirements and troubleshooting

• NixOS: the bundled binary won't run because of the dynamic loader path. The extension detects NixOS and skips the download, using arity on your PATH instead; install arity (for example via the arity package) or set arity.executableStrategy to path with arity.executablePath.
• Offline/restricted networks/proxies: the bundled-binary default works without network access. Only the explicit-version download paths (arity.version/arity.releaseTag) require GitHub connectivity.
• If a download fall-through fails, the extension shows a warning and falls back to looking up arity on the system PATH.

Settings

Arity registers itself as the default formatter for [r] files.

• arity.formatting.enable: contribute formatting edits (default: true).
• arity.diagnostics.enable: show diagnostics from the linter (default: true).
• arity.languageFeatures.enable: hover, completion, navigation, symbols, rename (including source() path updates when you move a file or folder), code actions, and the rest (default: true).
• arity.executableStrategy: how to locate the arity binary: bundled (default), environment, or path.
• arity.executablePath: path to the binary, used only when executableStrategy is path.
• arity.version: version to install (default: "latest").
• arity.releaseTag: advanced exact tag override (takes precedence if explicitly set).
• arity.githubRepo: GitHub repo for downloads (default: "jolars/arity").
• arity.serverArgs: extra args after arity lsp.
• arity.serverEnv: extra environment variables.
• arity.extraPath: extra PATH entries prepended for the language server process.
• arity.logLevel: log level for the language server, mapped to RUST_LOG (off, error, warn, info, debug, trace; unset by default). arity.serverEnv.RUST_LOG overrides this if both are set.
• arity.trace.server: LSP trace level (off, messages, verbose).

Security and trust

When arity.executableStrategy is bundled (the default), the extension prefers the binary that shipped inside the VSIX. If no bundled binary is available, or arity.version/arity.releaseTag is set explicitly, it downloads from GitHub releases configured by arity.githubRepo (default jolars/arity).