Parse review API 'show_grouped_ratings' param with a DRF BooleanField

Fixes issues we've been having with show_grouped_ratings='0' being
accepted as a truthy value, and makes things more coherent.

docs/topics/api/reviews.rst

@@ -23,7 +23,7 @@ combined together.
     :query string addon: The add-on id to fetch reviews from. When passed, the reviews shown will always be the latest posted by each user on this particular add-on (which means there should only be one review per user in the results).
     :query string filter: The :ref:`filter <review-filtering-param>` to apply.
     :query string user: The user id to fetch reviews from.
-    :query int show_grouped_ratings: Whether or not to show ratings aggregates for this add-on in the response.
+    :query boolean show_grouped_ratings: Whether or not to show ratings aggregates for this add-on in the response (Use "true"/"1" as truthy values, "0"/"false" as falsy ones).
     :>json int count: The number of results for this query.
     :>json string next: The URL of the next page of results.
     :>json string previous: The URL of the previous page of results.

src/olympia/reviews/tests/test_views.py

@@ -761,6 +761,9 @@ class TestReviewViewSetGet(TestCase):
         assert len(data['results']) == 2
         assert data['results'][0]['id'] == review2.pk
         assert data['results'][1]['id'] == review1.pk
+
+        if 'show_grouped_ratings' not in kwargs:
+            assert 'grouped_ratings' not in data
         return data
 
     def test_list_addon_queries(self):
@@ -864,13 +867,25 @@ class TestReviewViewSetGet(TestCase):
         assert data['results'][2]['reply']['body'] == reply1.body
 
     def test_list_addon_grouped_ratings(self):
-        data = self.test_list_addon(show_grouped_ratings=1)
+        data = self.test_list_addon(show_grouped_ratings='true')
         assert data['grouped_ratings']['1'] == 1
         assert data['grouped_ratings']['2'] == 1
         assert data['grouped_ratings']['3'] == 0
         assert data['grouped_ratings']['4'] == 0
         assert data['grouped_ratings']['5'] == 0
 
+    def test_list_addon_without_grouped_ratings(self):
+        data = self.test_list_addon(show_grouped_ratings='false')
+        assert 'grouped_ratings' not in data
+
+    def test_list_addon_with_funky_grouped_ratings_param(self):
+        response = self.client.get(self.url, {
+            'addon': self.addon.pk, 'show_grouped_ratings': 'blah'})
+        assert response.status_code == 400
+        data = json.loads(response.content)
+        assert data['detail'] == (
+            'show_grouped_ratings parameter should be a boolean')
+
     def test_list_addon_unknown(self, **kwargs):
         params = {'addon': self.addon.pk + 42}
         params.update(kwargs)

src/olympia/reviews/views.py

@@ -14,6 +14,7 @@ from django.utils.translation import ugettext as _
 
 import commonware.log
 from mobility.decorators import mobile_template
+from rest_framework import serializers
 from rest_framework.decorators import detail_route
 from rest_framework.exceptions import ParseError
 from rest_framework.permissions import AllowAny, IsAuthenticated
@@ -405,10 +406,17 @@ class ReviewViewSet(AddonChildMixin, ModelViewSet):
 
     def get_paginated_response(self, data):
         response = super(ReviewViewSet, self).get_paginated_response(data)
-        show_grouped_ratings = self.request.GET.get('show_grouped_ratings')
-        if show_grouped_ratings and self.get_addon_object():
-            response.data['grouped_ratings'] = dict(GroupedRating.get(
-                self.addon_object.id))
+        if 'show_grouped_ratings' in self.request.GET:
+            try:
+                show_grouped_ratings = (
+                    serializers.BooleanField().to_internal_value(
+                        self.request.GET['show_grouped_ratings']))
+            except serializers.ValidationError:
+                raise ParseError(
+                    'show_grouped_ratings parameter should be a boolean')
+            if show_grouped_ratings and self.get_addon_object():
+                response.data['grouped_ratings'] = dict(GroupedRating.get(
+                    self.addon_object.id))
         return response
 
     def get_queryset(self):