Fixed an issue related to missing optional applications

[GRoguelon]

The PR updates the deps_app/2 function in the Dialyxir.Project module in lib/dialyxir/project.ex to handle different versions of Elixir. Added version checking for Elixir 1.15 or later, and adjusted the implementation accordingly. The changes ensure that the deps_app/2 function works correctly with the appropriate version of Elixir.

I'm not totally sure if my change is backward compatible with previous versions of Elixir. Also not sure if there is a better option to avoid the version check.

I used this patch for an Elixir/Phoenix application on 1.15 for several weeks without any issues and no warnings about optional applications.

Closes #509

[axelson]

Thanks for this! I tested it on a work repository and it works as advertised 👍

This should be marked as Fixes #502 as well.

[jeremyjh]

Thanks!

[whatyouhide]

@jeremyjh @GRoguelon this inadvertently bumps the Elixir requirement to 1.14+ because it uses then/2. @GRoguelon maybe you wanna send a PR that doesn't use then/2, so that this stays compatible with Elixir 1.6+, like mix.exs declares? 🙃

[jeremyjh]

@whatyouhide I'm not sure this release is needed for older versions of Elixir, its mostly compatibility fixes for 1.15. I only test on the last 3 major versions. But, if its just using this one language feature thats an issue, maybe I should re-think that. Do you have projects stuck on older versions of Elixir?

[whatyouhide]

@jeremyjh what I’m saying is that if the library is only compatible with Elixir 1.15+, then we should change the requirement in mix.exs (here) to ~> 1.12. I see that you did that on the main branch, but the problem is that the 1.4.0 release declares it supports 1.6+, but it uses then/2, which was released in Elixir 1.12.

So right now it might be just a matter of releasing 1.4.1 as a bug fix 😉

[jeremyjh]

I released 1.4.1 last night.

[bryannaegele]

It would be nice if the change could be updated to not use then as while this project may only be testing 3 versions back, we have to support back further for some major libraries as we base off of supported OTP version rather than Elixir. We still have to support back to 1.11 for another year (OTP 27).

[David-Klemenc]

Something like this:

== Compilation error in file lib/dialyxir/project.ex ==
Error: ** (CompileError) lib/dialyxir/project.ex:365: undefined function then/2

if System.version() |> Version.parse!() |> (&(&1.major >= 1 and &1.minor >= 15)).() do