The default Elixir formatter has the philosophy of not modifying non metadata parts of the AST. Eunomo does not adhere to this philosophy and is meant to be used as an extension to the default formatter. As of now, the single use case is to sort import, alias and require definitions alphabetically.

See https://hexdocs.pm/eunomo for further documentation & https://github.com/Roberto-XY/eunomo for the source code.

The package can be installed by adding eunomo to your list of dependencies in mix.exs:

def deps do
  [
    {:eunomo, "~> 3.0.0", only: :dev}
  ]
end

Uses Elixir formatter plugin system.

# .formatter.exs
[
  # Usage of new formatter plugin system in Elixir `>= 1.13.0`.
  plugins: [Eunomo],
  eunomo_opts: [
    sort_alias: true,
    sort_import: true,
    sort_require: true
  ],
  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
]

Running mix format is going to take over as usal from here. All mix format options also apply to Eunomo plugins.

Before Elixir version 1.13.0, there was no way to hook plugins into the default formatter. Hence two Mix tasks were provided: mix eunomo.gen.config & mix eunomo. This approach does not play nicely with umbrella applications.