$ref with other fields

[ADR-007]

Hi!

Currenlty it doesn't work (the "readonly" is ignored):

Fix:
Change this:

drf-spectacular/drf_spectacular/plumbing.py

Line 236 in 9daf0ad

return {'$ref': f'#/components/{self.type}/{self.name}'}

to:

        return {'allOf': [{'$ref': f'#/components/{self.type}/{self.name}'}]}

Result (inheritance with overriding):

(it doesn't look like the correct way to fix it. so, it is just example)

[ADR-007]

my workaround:

    def _map_serializer_field(self, method, field):
        field = super()._map_serializer_field(method, field)

        if '$ref' in field:
            all_of = field.setdefault('allOf', [])
            all_of.append({'$ref': field.pop('$ref')})

        return field

[tfranzel]

that was a good catch. the spec is not 100% clear, if that actually behaves as intended. at least its more valid than before 😁 Also SwaggerUI properly recognizes it so that should be good enough here.