bug: alias lifting produces broken code when aliases conflict with other existing usages

[jsw800]

Versions

• Elixir: 1.17.1
• Styler: 1.0.0

Example Input

Before running mix format:

defmodule SomeModule do
  def do_something(token) do
    # Guardian.Token.Jwt is a library module in the guardian library
    # MyApp.Guardian is a module defined inside my application
    Guardian.Token.Jwt.decode_token(MyApp.Guardian, token)
  end

  def do_something_else do
    Application.get_env(:my_app, MyApp.Guardian)
  end
end

Stacktrace / Current Behaviour

After running mix format:

defmodule SomeModule do
  alias MyApp.Guardian

  def do_something(token) do
    # elixir now can't find the Guardian.Token.Jwt module because it is
    # looking for MyApp.Guardian.Token.Jwt which is not a real module
    Guardian.Token.Jwt.decode_token(Guardian, token)
  end

  def do_something_else do
    Application.get_env(:my_app, Guardian)
  end
end

[novaugust]

thanks for the report! definitely something styler's supposed to notice, sorry that it's got a bug there

[novaugust]

hey @jsw800 , i wasn't able to reproduce the issue with the snippet you gave me:

https://github.com/adobe/elixir-styler/compare/me/fix-193?expand=1

tests still pass. is there more context you can provide?

[jsw800]

Ah sorry about that - I had kinda changed it from my original code so as to not share my actual source code. It looks like the difference between my original code and the example I shared is that MyApp.Guardian was actually MyApp.Something.Guardian. When the code looks like this, the test fails as expected:

defmodule SomeModule do
  @moduledoc false

  def do_something(token) do
    # Guardian.Token.Jwt is a library module in the guardian library
    # MyApp.Something.Guardian is a module defined inside my application
    Guardian.Token.Jwt.decode_token(MyApp.Something.Guardian, token)
  end

  def do_something_else do
    Application.get_env(:my_app, MyApp.Something.Guardian)
  end
end

[novaugust]

ty, got it now :)