Dialyzer error when specifying Queries in module attributes in compiled helpers

[TheFirstAvenger]

Example Repo: https://github.com/TheFirstAvenger/wallaby_dialyzer_issue

If you have compiled test helpers, and use module attributes to specify Queries, then functions that call fill_in, click, or assert_has will throw the Dialyzer "no return" error. These show up as errors in IDE tools like ElixirLS.

  @doc """
  This version has inline Queries.
  There is no dialyzer error on this version
  """
  def log_in_no_error(session) do
    session
    |> Browser.visit("/login")
    |> Browser.fill_in(Query.text_field("username"), with: "me")
    |> Browser.click(Query.css("button", text: "Log in"))
    |> Browser.assert_has(Query.css("h1", text: "Logged In!"))
  end

  @username_field Query.text_field("username")
  @log_in_button Query.css("button", text: "Log in")
  @logged_in_h1 Query.css("h1", text: "Logged In!")

  @doc """
  This version uses module atttributes for it's queries
  This results in the Dialyzer error "Function log_in_has_no_return/1 has no local return."
  """
  def log_in_has_no_return(session) do
    session
    |> Browser.visit("/login")
    |> Browser.fill_in(@username_field, with: "me")
    |> Browser.click(@log_in_button)
    |> Browser.assert_has(@logged_in_h1)
  end

[michallepicki]

Thanks for the repro repository!

I'll look into it - I am familiar with Wallaby codebase and I have some experience fixing dialyzer in application code. So far I have been ignoring dialyzer issues in my projects wallaby tests - this is a good starting point to change this :)

[michallepicki]

@TheFirstAvenger This should be fixed on master now, to confirm you can try it out by specifying {:wallaby, github: "elixir-wallaby/wallaby", only: :test}, in your project

[mhanberg]

I can publish a patch release once you've confirmed it works @TheFirstAvenger.

Thanks for taking the time to open an issue and create a bug demo project, we appreciate it!

🍻

[TheFirstAvenger]

@mhanberg Confirmed, that fixed it, thanks!

[mhanberg]

@TheFirstAvenger the fix has been released with v0.26.2

[TheFirstAvenger]

@mhanberg Thank you!