Biomine

Elixir bindings for the Biome formatter, exposed as a Rust NIF. Format JavaScript/TypeScript and CSS source directly from Elixir without shelling out to Node.

iex> Biomine.format_js("const  x=1")
{:ok, "const x = 1;\n"}

Installation

Add biomine to your list of dependencies in mix.exs:

def deps do
  [
    {:biomine, "~> 0.1.0"}
  ]
end

The NIF ships as a precompiled binary via rustler_precompiled, so you do not need a Rust toolchain to use this library — the matching artifact for your OS, architecture, and NIF version is downloaded automatically at compile time.

Mix formatter plugin

Biomine can be used as a mix format plugin for JavaScript and TypeScript files. Add the plugin and the file extensions you want Mix to format to your .formatter.exs:

[
  plugins: [Biomine.Mix.JsFormatter],
  inputs: [
    "{mix,.formatter}.exs",
    "{config,lib,test}/**/*.{ex,exs}",
    "assets/**/*.{js,jsx,ts,tsx}"
  ]
]

Formatter options can be passed with the :biomine key:

[
  plugins: [Biomine.Mix.JsFormatter],
  biomine: [
    js: [
      quote_style: :single,
      semicolons: :as_needed
    ]
  ],
  inputs: [
    "{mix,.formatter}.exs",
    "{config,lib,test}/**/*.{ex,exs}",
    "assets/**/*.{js,jsx,ts,tsx}"
  ]
]

Biomine can also format CSS files with Biomine.Mix.CssFormatter. It honors the same :biomine options key, with CSS options nested under :css and documented in Biomine.format_css/2:

[
  plugins: [Biomine.Mix.JsFormatter, Biomine.Mix.CssFormatter],
  biomine: [
    js: [
      quote_style: :single
    ],
    css: [
      quote_style: :single
    ]
  ],
  inputs: [
    "{mix,.formatter}.exs",
    "{config,lib,test}/**/*.{ex,exs}",
    "assets/**/*.{js,jsx,ts,tsx,css}"
  ]
]

Phoenix.LiveView.HTMLFormatter tag formatter

Biomine can also format <script> tags inside .heex templates — including colocated hooks — when used as a Phoenix.LiveView.HTMLFormatter.TagFormatter. Add it to your .formatter.exs alongside Phoenix.LiveView.HTMLFormatter:

[
  plugins: [Phoenix.LiveView.HTMLFormatter],
  tag_formatters: %{script: Biomine.LiveView.TagFormatter},
  inputs: [
    "{mix,.formatter}.exs",
    "{config,lib,test}/**/*.{ex,exs,heex}"
  ]
]

This requires :phoenix_live_view (~> 1.2) in your own dependencies, since that's where Phoenix.LiveView.HTMLFormatter and the TagFormatter behaviour live. The same :biomine options key used by the Mix formatter plugin above is honored here too, using the nested :js options.

Building from source

You only need this if you are hacking on the NIF, or you are on a target for which no precompiled artifact is published.

Prerequisites: a Rust toolchain and Elixir/Erlang.

Set the BIOMINE_BUILD environment variable to force compilation from source instead of downloading:

export BIOMINE_BUILD=1
mix deps.get
mix compile

Alternatively, force it from config/config.exs:

config :rustler_precompiled, :force_build, biomine: true

Building from source requires rustler (already declared as an optional dependency).

Releasing precompiled binaries

Precompiled binaries are built by the .github/workflows/release.yml workflow.

1. Bump @version in mix.exs and push a matching git tag (e.g. v0.1.0). CI builds each target and attaches the .tar.gz artifacts to the GitHub release.

2. Generate and commit the checksum file:

   mix rustler_precompiled.download Biomine.Native --all --print
   

   This produces checksum-Elixir.Biomine.Native.exs, which must be committed and included in the Hex package.

3. Publish to Hex with mix hex.publish.

Documentation

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/biomine.