How to generate schema for multiple choice filter?

Question

In our API we have an endpoint to list locations. We allow filtering on location type, and we allow multiple values for this filter. For example:

GET /location/?type=hotel&type=airport

For filtering we are using django-filter. However, drf-yasg doesn't seem to correctly generate the schema for this parameter.

The view class can be boiled down to this:

from rest_framework.generics import ListAPIView
from .models import Location
from .serializers import LocationListSerializer
from .filters import LocationFilterSet
from django_filters.rest_framework import DjangoFilterBackend

class LocationListView(ListAPIView):
    queryset = Location.objects.all()
    serializer_class = LocationListSerializer
    filter_backends = (
        DjangoFilterBackend,
    )
    filter_class = LocationFilterSet

and the filter class looks like this:

from django_filters import rest_framework as filters
from .models import Location

class LocationFilterSet(filters.FilterSet):
    type = filters.MultipleChoiceFilter(choices=Location.TYPE_CHOICES)

    class Meta:
        model = Location
        fields = (
            'type',
        )

This view works as intended - the following test passes:

from django.test import TestCase
from django.urls import reverse
from rest_framework import status
from .models import Location

class TestLocationView(TestCase):
    def test_filter_by_multiple_types(self):
        Location.objects.create(type='airport')
        Location.objects.create(type='hotel')
        Location.objects.create(type='home')
        response = self.client.get('/location/?type=hotel&type=airport')
        self.assertEqual(len(response.data), 2)

I'd expect the generated yaml for this parameter to look like this:

parameters:
- name: type
  in: query
  description: ''
  required: false
  schema:
      type: array
      items:
          type: string
  explode: true

but instead, it looks like this:

- name: type
  in: query
  description: ''
  required: false
  type: string

Is this a limitation of drf-yasg?

It's not possible to use swagger_auto_schema's query_serializer since it doesn't allow overriding the schemas generated by the filter backends.

This seems to happen because django_filters.rest_framework.backends.DjangoFilterBackend.get_coreschema_field only outputs two field types, number and strings. I went ahead and overrode that method, however, it then throws errors in drf_yasg.inspectors.query.CoreAPICompatInspector.coreapi_field_to_parameter, doesn't accept the array type.