I have a library that wants to find all modules for a given behaviour. I found some description that showed how to do this off of :code.all_loaded() which was neat. Then I moved the library out of the application it was living in because it really isn’t supposed to be an application on its own. And things started breaking intermittently during testing.

So that’s when I found out about Elixir doing lazy loading of modules through this thread. But the build_embedded stuff only really seems to apply to an application.

Should I just use another approach for this? I want to find all modules that are widgets. I was doing this at runtime, building the list when it was first requested and persisting it to the Application environment. I don’t really care if the initial list is made at compile time or runtime. Ideally it should also be able to register new Widgets if they are loaded at runtime or come from outside the library.

Is there a common pattern recommended here that I’m just not familiar with? I realize this is state but the library is mostly pure functions so avoiding needing to start a supervision tree for the lib would be more elegant.