Support for Pydantic

[miquelvir]

This seems a solid foundation. It would be awesome if you added support for using Pydantic schemas and/or using Typing annotations. Starting stone here (https://github.com/bauerji/flask_pydantic). Is this something you would be interested in?

[RookieRick]

👋 There has been some discussion/interest around adding support for Pydantic. Will have a look at flask_pydantic - would be awesome if we can leverage what they've already built without reinventing the wheel and I see there's discussion over there around adding OpenAPI generation (bauerji/flask-pydantic#17) so potentially a nice win-win for both projects!

[barakalon]

Personally, I don't think flask-rebar should aim to support Pydantic. I think this would be trying to do too many things.

Flask-rebar is mostly a little glue between the real heavy-lifters: Flask, Marshmallow, and OpenAPI. If you remove this glue, I'm not sure how much code is actually left in Flask-rebar.

In other words, the majority of code in Flask-rebar is a specific to Marshmallow - Marshmallow validation/marshaling integration, conversion between Marshmallow schemas and OpenAPI, etc.
If we add support for Pydantic, I feel like we might as well write an entirely new package.

Instead, I think we should aim for better support for type annotations. Flask-rebar was written several years ago and was intended to support Python 2. As Python 2 itself is no longer supported and type annotations are becoming standard, I think we can give Flask-rebar a typing facelift.

When it comes to typed request/response objects, perhaps we should stick with something based on Marshmallow. There are some existing packages out there:

• https://github.com/lovasoa/marshmallow_dataclass
• https://github.com/sv-tools/marshmallow-objects

But both of those are pretty small, so it could also make sense to roll our own instead of taking on an additional dependency.

tldr:
❌ Pydantic support
✅ Type annotations

[dekim24]

I'm actually planning to add type annotations (+ mypy support?) as my next ADSK hack week project