Fix missing Field.default when it's value is None in openapi spec

[ddorian]

Checklist:

• Run pytest tests and no failed.
• Run ruff check flask_openapi3 tests examples and no failed.
• Run mypy flask_openapi3 and no failed.
• Run mkdocs serve and no failed.

[luolingchun]

Why components only?

[ddorian]

The other models have many fields with default None that show up in the output (example=None, security=None, deprecated=None etc).

This worked for me on a 5K lines json schema.

[luolingchun]

I agree to replace exclude_none with exclude_unset, but I don't think it's perfect just for components.
Can you write an example of an error other than the action components?

[ddorian]

Using this:

self.spec_json = spec.model_dump(mode="json", by_alias=True, exclude_unset=True, warnings=False)

These are the fields that get removed:

RequestBody.required = True

These are the extra fields that show up in json. I guess they are being set from functions.

Operation.deprecated = None
Operation.externalDocs = None
Opeation.example = None
Operation.examples = None
Operation.servers = None
Operation.security = None
Parameter.deprecated = None
Parameter.example = None
Parameter.examples = None

So we can do my way or fix functions that set the values above to None.

[luolingchun]

Some models end up in parameters, so just using the unset rule in components is not a good solution.

I committed a commit with all assignments using the unset rule.

Hopefully we can agree.

[ddorian]

Works great for me.

[ddorian]

After my 2 commits my tests are fine and the json is valid openapi spec.

[ddorian]

@luolingchun can you merge my 2 PRs?

[ddorian]

On paths without parameters, parameters shows as null, but it's not an issue.

---

After this, we can add even more defaults to make the code nicer. Like setting:

# instead of 
webhooks: Optional[Dict[str, Union[PathItem, Reference]]] = None
# we do
webhooks: Dict[str, Union[PathItem, Reference]] = {}
# and output should be the same in all cases