[DISCUSS] Should the base.handlers have their counterpart in extension.handlers?

[echarles]

While converting JupyerLab Server to a Server Extension, it has been pretty easy to implement class LabServerApp(ExtensionAppJinjaMixin, ExtensionApp)

This works fine without touching the handlers which are still the old classical flavor (not a ExtensionHandler). If we also want to have the handler as pure extension, there are a bunch of code to be duplicated: the base.handlers.py (APIHandler...) should be replicated in something like extensions.base_handler.py.

Do we want to go this way? Maybe the base.handlers.py could extend/reuse the extensions.base_handler.py?

[Zsailer]

See my comments in #174.

[echarles]

This question has been solved making the ExtensionApp a Mixin.

Closing.