🐛 Fix issues introduced by removing SQLAlchemy safeguard in jsonable_encoder

[tiangolo]

🐛 Fix issues introduced by removing SQLAlchemy safeguard in jsonable_encoder.

The jsonable_encoder originally had a sqlalchemy_safe=True parameter that would avoid trying to encode any object attribute starting with _sa, as SQLAlchemy creates several attributes with that prefix in the models.

It was there as a quick and early workaround/hack to allow working with SQLAlchemy easily. But I didn't really want to have ORM-specific logic in FastAPI, as FastAPI is independent of ORM (or DB, you could just use MongoDB or ElasticSearch as well).

The main workflow for using any type of ORM with FastAPI is with Pydantic's ORM mode, as described in Tutorial: SQL (Relational) Databases that feature has been there for a long while. So I expected the jsonable_encoder to no longer need that workaround. But I had used the same workaround in e.g. the project generator: https://github.com/tiangolo/full-stack-fastapi-postgresql/blob/master/%7B%7Bcookiecutter.project_slug%7D%7D/backend/app/app/crud/base.py#L35 🤦

So, for now, I'm reverting it, for the cases that depended on it, as noticed by @shawnwall on #1864 (comment)

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Later I would like to remove the SQLAlchemy-specific logic.

But I think it would have to be something like discarding arbitrary object attributes that start with _ (but this would include, e.g. a MongoDB ORM object with an _id attribute). Although this would only apply to objects, not dictionaries. And only in the case where it's an arbitrary object, not a Pydantic model.

[codecov]

Codecov Report

Merging #1987 into master will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master     #1987   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          239       239           
  Lines         7079      7079           
=========================================
  Hits          7079      7079           

Impacted Files	Coverage Δ
fastapi/encoders.py	100.00% <100.00%> (ø)

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[github-actions]

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