Quokka

Quokka is an Elixir formatter plugin that's combination of mix format and mix credo, except instead of telling you what's wrong, it just rewrites the code for you to fit its style rules.

Quokka is a fork of Styler that checks the credo config to determine which rules to rewrite.

Features

• auto-fixes many credo rules, meaning you can turn them off to speed credo up
• keeps a strict module layout
  • alphabetizes module directives
• extracts repeated aliases
• makes your pipe chains pretty as can be
  • pipes and unpipes function calls based on the number of calls
  • optimizes standard library calls (a |> Enum.map(m) |> Enum.into(Map.new) => Map.new(a, m))
• replaces strings with sigils when the string has many escaped quotes
• reorders configuration in config files
• expands multi-alias/import statements
• enforces consistent function call parentheses
• ensures consistent spacing around operators
• formats documentation comments
• removes unnecessary parentheses
• simplifies boolean expressions
• enforces consistent module attribute usage
• formats and organizes typespecs
• ... and many more style improvements

See our Rewrites documentation on hexdocs

Installation

Add :quokka as a dependency to your project's mix.exs:

def deps do
  [
    {:quokka, "~> 0.1", only: [:dev, :test], runtime: false},
  ]
end

Then add Quokka as a plugin to your .formatter.exs file

[
  plugins: [Quokka]
]

And that's it! Now when you run mix format you'll also get the benefits of Quokka's Stylish Stylings.

Speed: Expect the first run to take some time as Quokka rewrites violations of styles and bottlenecks on disk I/O. Subsequent formats formats won't take noticeably more time.

Configuration

Quokka can be configured in your .formatter.exs file

[
  plugins: [Quokka],
  quokka: [
    alias_lifting_exclude: [...],
    reorder_configs: true | false
  ]
]

Quokka has several configuration options:

• :alias_lifting_exclude, which accepts a list of atoms to not lift. See the Module Directive documentation for more
• :reorder_configs, which controls whether or not the configs in your config/*.exs files are alphabetized. This is true by default.

WARNING: Quokka can change the behaviour of your program!

In some cases, this can introduce bugs. It goes without saying, but look over your changes before committing to main :)

Some ways Quokka can change your program:

• with statement rewrites
• config file sorting
• and likely other ways. stay safe out there!

License

Quokka is licensed under the Apache 2.0 license. See the LICENSE file for more details.