App.extend() not type hint friendly?

This may be an incorrect usage of App.extend() but when my CLI starts it creates an instance of a github client that gets used in a Github Cement controller:

app.extend("github", Github(access_token))

With this method of extending, I beleive you lose access for python’s type hints to be aware of what app.github is and therefore you lose things like autocompletion in VS Code.

Possibly there is a better way to handle this use case?

[tomekr]

Yea it looks like self.app.* gets lost as well. This is a screenshot from a newly generated todo tutorial app:

Back in the top-level main.py it looks like app is an instance of MyApp but the type system can’t figure out the handlers.

[coccoinomane]

Any feedback, ideas, solutions here would be greatly appreciated.

Hi @derks !

As a workaround, what about casting self.app.* to App? It works when done in the controller class:

Code completion works up to the first level, meaning that app.self.* is discovered, but app.self.config.* isn’t. This could be solved:

1. by also casting app’s attributes (eg. app.self.config and app.self.config.cache) to their type, but only after these attributes have been set; or
2. by defining getter functions in the controller with an explict return type, for example:

   from cement.core.config import ConfigInterface
   from cement.core.cache import CacheInterface
   
   def get_config(self) -> ConfigInterface:
       return self.app.config
   
   def get_cache(self) -> CacheInterface:
       return self.app.cache
   

Cheers, Cocco

PS: Please note that, in the screenshot, I missed a super().__init__() in the first line of the __init__() method.