From 2052324a029ffab1e3ec63b2200ca20a965efb9d Mon Sep 17 00:00:00 2001
From: Tomasz Glowka <glowka.tom@gmail.com>
Date: Sat, 13 Jun 2020 14:11:23 +0200
Subject: [PATCH] Add get_serializer check and warning

---
 CHANGELOG.md                         |  1 +
 drf_yasg_json_api/inspectors/view.py | 25 +++++++++++++++++++------
 tests/test_serializer_schema.py      | 25 +++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bcd6565..4302a95 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 ------------------
 
 - Add support for string-based `included_serializers`
+- Warn about missing `get_serializer` for view's list action
 
 0.6.0 (2020-04-11)
 ------------------
diff --git a/drf_yasg_json_api/inspectors/view.py b/drf_yasg_json_api/inspectors/view.py
index abc3d05..14f95a9 100644
--- a/drf_yasg_json_api/inspectors/view.py
+++ b/drf_yasg_json_api/inspectors/view.py
@@ -1,10 +1,11 @@
+import logging
+
 from collections import OrderedDict
 
 from drf_yasg import inspectors
 from drf_yasg import openapi
 from drf_yasg.utils import filter_none
 from drf_yasg.utils import guess_response_status
-from drf_yasg.utils import is_list_view
 from rest_framework_json_api.utils import format_value
 from rest_framework_json_api.utils import get_included_serializers
 from rest_framework_json_api.utils import get_resource_type_from_serializer
@@ -16,6 +17,8 @@
     'SwaggerAutoSchema',
 ]
 
+logger = logging.getLogger(__name__)
+
 
 class SwaggerAutoSchema(inspectors.SwaggerAutoSchema):
     def get_request_body_schema(self, serializer):
@@ -54,12 +57,22 @@ def get_default_responses(self):
         return filter_none(OrderedDict({str(default_status): default_schema}))
 
     def get_default_response_data(self, default_serializer):
-        default_data_schema = ''
-        if default_serializer and not isinstance(default_serializer, openapi.Schema):
+        if isinstance(default_serializer, openapi.Schema):
+            default_data_schema = default_serializer
+        elif default_serializer:
             default_data_schema = self.serializer_to_schema(default_serializer) or ''
-
-        if is_list_view(self.path, self.method, self.view) and self.method.lower() == 'get':
-            default_data_schema = openapi.Schema(type=openapi.TYPE_ARRAY, items=default_data_schema)
+        else:
+            default_data_schema = ''
+
+        if self.is_list_view() and self.method.lower() == 'get':
+            if default_data_schema:
+                default_data_schema = openapi.Schema(type=openapi.TYPE_ARRAY, items=default_data_schema)
+            else:
+                logger.warning(
+                    'Missing schema definition for list action of {view_name}, have you defined get_serializer?'.format(
+                        view_name=self.view.__class__.__name__
+                    )
+                )
 
         return default_data_schema
 
diff --git a/tests/test_serializer_schema.py b/tests/test_serializer_schema.py
index 84efba8..8237bb5 100644
--- a/tests/test_serializer_schema.py
+++ b/tests/test_serializer_schema.py
@@ -5,11 +5,13 @@
 import drf_yasg.inspectors
 import pytest
 
+from django.conf.urls import url
 from django.db import models
 from drf_yasg import openapi
 from drf_yasg.generators import OpenAPISchemaGenerator
 from rest_framework import mixins
 from rest_framework import routers
+from rest_framework import views
 from rest_framework import viewsets
 from rest_framework_json_api import django_filters
 from rest_framework_json_api import filters
@@ -150,6 +152,29 @@ class ProjectViewSet(mixins.ListModelMixin, viewsets.GenericViewSet):
     assert set(pagination_response_schema.keys()) == {'page', 'pages', 'count'}
 
 
+@mock.patch('drf_yasg_json_api.inspectors.view.logger')
+def test_get__list_missing_serializer_warning(logger):
+    class ProjectView(views.APIView):
+        renderer_classes = [renderers.JSONRenderer]
+        parser_classes = [parsers.JSONParser]
+        swagger_schema = BasicSwaggerAutoSchema
+
+        def get(*args, **kwargs):
+            pass
+
+    urlpatterns = [
+        url('projects/', ProjectView.as_view())
+    ]
+
+    generator = OpenAPISchemaGenerator(info=openapi.Info(title="", default_version=""), patterns=urlpatterns)
+
+    swagger = generator.get_schema(None, True)
+
+    assert swagger['paths']['/projects/']['get']
+    logger.warning.assert_called_once_with('Missing schema definition for list action of ProjectView, '
+                                           'have you defined get_serializer?')
+
+
 def test_get__included():
     class MemberSerializer(serializers.ModelSerializer):
         # projects = serializers.ResourceRelatedField(many=True, read_only=True)