Fix 500 error on /api/v1/venues/byslug/my-bar/beers/ (#237)

Addresses #236.

venues/test/test_views.py

@@ -7,8 +7,10 @@
 from faker import Faker
 
 from hsv_dot_beer.users.test.factories import UserFactory
+from beers.models import Beer
 from venues.models import Venue, VenueAPIConfiguration
-from beers.test.factories import BeerFactory
+from beers.test.factories import BeerFactory, ManufacturerFactory
+from taps.models import Tap
 from taps.test.factories import TapFactory
 from .factories import VenueFactory
 
@@ -98,6 +100,24 @@ def test_get_ok(self):
         self.assertEqual(response.status_code, 200, response.data)
         self.assertEqual(response.data['id'], self.venue.id)
 
+    def test_beers(self):
+        mfg = ManufacturerFactory()
+        beers = Beer.objects.bulk_create(BeerFactory.build(
+            manufacturer=mfg
+        ) for dummy in range(10))
+        taps = Tap.objects.bulk_create(
+            Tap(
+                beer=beer,
+                tap_number=index + 1,
+                venue=self.venue,
+            ) for index, beer in enumerate(beers)
+        )
+        response = self.client.get(f'{self.url}beers/')
+        self.assertEqual(len(taps), len(beers))
+        self.assertEqual(Beer.objects.count(), len(beers))
+        self.assertEqual(response.status_code, 200, response.data)
+        self.assertEqual(len(response.data['results']), len(beers))
+
 
 class TestVenueDetailTestCase(APITestCase):
     """

venues/views.py

@@ -43,6 +43,26 @@ class VenueBySlugViewSet(VenueViewSet):
     def list(self, request, *args, **kwargs):
         raise NotFound()
 
+    @method_decorator(cache_page(60 * 5))
+    @action(detail=True, methods=['GET'])
+    def beers(self, request, slug):
+        from beers.views import BeerViewSet
+        from beers.filters import BeerFilterSet
+
+        queryset = BeerViewSet.queryset.filter(
+            **{f'taps__venue__{self.lookup_field}': slug}
+        ).distinct()
+
+        # let the user use all the beer filters just for kicks
+        queryset = BeerFilterSet(request.query_params, queryset=queryset).qs
+
+        page = self.paginate_queryset(queryset)
+        if page is not None:
+            serializer = BeerViewSet.serializer_class(page, many=True)
+            return self.get_paginated_response(serializer.data)
+        serializer = BeerViewSet.serializer_class(queryset, many=True)
+        return Response(serializer.data)
+
     lookup_field = 'slug'
     serializer_class = serializers.VenueBySlugSerializer