💡 per controller middlewares and exception handlers

[lucas-labs]

Some context...

• FastAPI doesn't support this at all AFAIK.
• starlette has an implementation for middlewares per group of routes on Mount:

https://github.com/encode/starlette/blob/93494a46ee0f2e8b1eeafd12e466ebac15037b41/starlette/routing.py#L380-L396

The problem with this is that if we use Mount instead of a subclass of APIRoute in FastAPI, we lose automatic openai schema definitions for those routes. They work just fine, we can access, routing works but FastAPI won't take them into account for its openai schema creation.

This is why:
https://github.com/tiangolo/fastapi/blob/ac93277d3b506f4076aee1af6ae5a86406f545c6/fastapi/openapi/utils.py#L481-L484

FastApi will ignore Mount objects inside its routes list.

Initial solution proposal

The only solution I can think of right now, would be to make our own implementation of Mount (e.g. PestMount), so that when we define a @controller, instead of creating an APIRouter for it and then add it to the FastAPI application, we create a PestMount grouping all the routes of the controller inside it.

Then we should mess a bit with the PestApplication class, overriding the openapi method from FastAPI so that it not only takes APIRoutes into account when generating the schema, but also all routes included on the PestMount route container.