Styles up module directives!

This Style will expand multi-aliases/requires/imports/use and sort the directive within its groups (except uses, which cannot be sorted) It also adds a blank line after each directive group.

Credo rules

Rewrites for the following Credo rules:

• Credo.Check.Consistency.MultiAliasImportRequireUse (force expansion)
• Credo.Check.Readability.AliasOrder (we sort __MODULE__, which credo doesn't)
• Credo.Check.Readability.ModuleDoc (adds @moduledoc false if missing. includes *.exs files)
• Credo.Check.Readability.MultiAlias
• Credo.Check.Readability.StrictModuleLayout (see section below for details)
• Credo.Check.Readability.UnnecessaryAliasExpansion
• Credo.Check.Design.AliasUsage

Breakages

This can break your code.

Strict Layout

Modules directives are sorted into the following order:

• @shortdoc
• @moduledoc
• @behaviour
• use
• import
• alias
• require
• everything else (unchanged)

If any of the sorted directives had a dependency on code that is now below it, your code will fail to compile after being styled.

For instance, the following will be broken because the module attribute definition will be moved below the use clause, meaning @pi is undefined when invoked.

  # before
  defmodule Approximation do
    @pi 3.14
    use Math, pi: @pi
  end

  # after
  defmodule Approximation do
    @moduledoc false
    use Math, pi: @pi
    @pi 3.14
  end

For now, it's up to you to come up with a fix for this issue. Sorry!

Strict Layout: interwoven conflicting aliases

Ideally no one writes code like this as it's hard for our human brains to notice the context switching! Still, it's a possible source of breakages in Styler.

alias Foo.Bar Bar.Baz.bop()

alias Baz.Bar Bar.Baz.bop()

# becomes

alias Baz.Bar alias Baz.Bar.Baz alias Foo.Bar Baz.bop() # was Foo.Bar.Baz, is now Baz.Bar.Baz Baz.bop()