Biome (bunx) Formatter

A minimal VSCode formatter that runs Biome via bunx @biomejs/biome — no global install, no local node_modules requirement.

Why

The official Biome extension expects Biome to be installed in your project (or globally). This one doesn't: it shells out to bunx, which fetches and caches @biomejs/biome on first use. Useful when you work across many repos and don't want to install Biome in each one.

Requirements

• Bun on your PATH (or at ~/.bun/bin/bunx, /opt/homebrew/bin/bunx, or /usr/local/bin/bunx)
• A biome.json (or biome.jsonc) somewhere in the workspace — Biome auto-discovers it from the workspace folder

Setup

Set this extension as the default formatter for the languages you want, in your User or Workspace settings.json:

{
  "editor.formatOnSave": true,
  "[typescript]":      { "editor.defaultFormatter": "vladstudio.biome-bunx-formatter" },
  "[typescriptreact]": { "editor.defaultFormatter": "vladstudio.biome-bunx-formatter" },
  "[javascript]":      { "editor.defaultFormatter": "vladstudio.biome-bunx-formatter" },
  "[javascriptreact]": { "editor.defaultFormatter": "vladstudio.biome-bunx-formatter" },
  "[json]":            { "editor.defaultFormatter": "vladstudio.biome-bunx-formatter" },
  "[jsonc]":           { "editor.defaultFormatter": "vladstudio.biome-bunx-formatter" }
}

Reload the window. Hit your format shortcut (default ⌥⇧F on macOS) or save the file.

Supported languages

JavaScript, TypeScript, JSX, TSX, JSON, JSONC, CSS, HTML, Vue, Svelte, Astro, GraphQL, YAML.

How it works

On format, the extension spawns bunx @biomejs/biome format --stdin-file-path=<file> with cwd set to the workspace folder, pipes the buffer over stdin, and replaces the document with stdout. On nonzero exit (e.g. syntax error) it logs to the Biome (bunx) output channel and makes no edits — the file is never wiped.

First format is slow while bunx downloads @biomejs/biome; subsequent runs are fast (Bun caches the package).

License

MIT