Versions

currently on main, but 0.12 when it gets cut

Example Input

lifting is smart enough to not interact with quote children, but user-defined macros can hide that that's occurring.

defmodule Foo do
  @moduledoc false

  my_quote do
    alias AliasFor.In.MyQuote

    ... Foo.Bar.Baz... 
    ... Foo.Bar.Baz ...
  end
end

results in:

defmodule Foo do
  @moduledoc false
  alias Foo.Bar.Baz

  my_quote do
    alias AliasFor.In.MyQuote

    ... Baz... 
    ... Baz ...
  end
end

but as with quote, the compiler will warn that Baz is unused within Foo, and anything that uses my_quote will then error on Baz being undefined

as-is, the user will have to put the alias where it belongs inside my_quote, which styler is just fine with and will leave be. still, i'd like styler to not leave a codebase uncompilable, even if it just requires a simple human fix

Fix

I see two possible

1. never go into do blocks of unknown parents looking for liftable aliases (allowlist all kernel forms and nothing else)
2. when a do-block contains a module directive, assume that it's equivalent to a quote block and back out of it

there are pros and cons to each, but 2 probably gives the more correct result, with the downside being a more complex look-ahead implementation. actually, the real win might be doing a combination of both: when encounter directives in a nested scope, figure out if it's a known block parent. if it is, carry on. if it's not, assume this works as a quote does and don't lift