Should SearchFilter.get_schema_operation_parameters return anything if view doesn't declare search_fields?

[edi-monefy]

I have the following setup:

# views
class AppointmentViewSet(ModelViewSet):
    queryset = models.Appointment.objects.all()
    ordering = ['pk']

# settings
REST_FRAMEWORK = {
    # ...
    'DEFAULT_FILTER_BACKENDS': [
        'django_filters.rest_framework.DjangoFilterBackend',
        'rest_framework.filters.OrderingFilter',
        'rest_framework.filters.SearchFilter',
    ],
    # ...
}

As you can see, my viewset doesn't define search_fields, even though the SearchFilter backend is used (in theory, but not in practice). It appears that the SearchFilter backend returns the search operation param, even though my view doesn't actually use the search feature.

I've tracked this down to rest_framework.filters.SearchFilter.get_schema_operation_parameters, where it doesn't check if the view has a search_fields attribute (and perhaps also check if it's not empty). This doesn't really cause problems in the browsable API, but does add a search param to all OpenAPI schema operations (courtesy of drf-spectacular). Needless to say that param is useless, because of no search fields on the view.

The question I wanted to bring up is: shouldn't get_schema_operation_parameters check whether the view actually declares some search fields and only return the search param in that case? Seems pretty sensible to me, but would like other people's opinion. The workaround (and proposed solution if this turns out to be a good idea) would be something like:

from rest_framework.filters import SearchFilter as BaseSearchFilter

class SearchFilter(BaseSearchFilter):
    def get_schema_operation_parameters(self, view):
        search_fields = getattr(view, 'search_fields', None)

        if search_fields:
            return super().get_schema_operation_parameters(view)

        return []