improve docstring extraction #96

Author: tfranzel

drf_spectacular/openapi.py

@@ -1,4 +1,3 @@
-import inspect
 import re
 import typing
 from operator import attrgetter
@@ -23,8 +22,8 @@
 from drf_spectacular.plumbing import (
     ComponentRegistry, ResolvedComponent, anyisinstance, append_meta, build_array_type,
     build_basic_type, build_choice_field, build_object_type, build_parameter_type, error,
-    follow_field_source, force_instance, get_override, has_override, is_basic_type, is_field,
-    is_serializer, resolve_regex_path_parameter, safe_ref, warn,
+    follow_field_source, force_instance, get_doc, get_override, has_override, is_basic_type,
+    is_field, is_serializer, resolve_regex_path_parameter, safe_ref, warn,
 )
 from drf_spectacular.settings import spectacular_settings
 from drf_spectacular.types import OpenApiTypes
@@ -171,8 +170,8 @@ def dict_helper(parameters):
     def get_description(self):
         """ override this for custom behaviour """
         action_or_method = getattr(self.view, getattr(self.view, 'action', self.method.lower()), None)
-        view_doc = inspect.getdoc(self.view) or ''
-        action_doc = inspect.getdoc(action_or_method) or ''
+        view_doc = get_doc(self.view.__class__)
+        action_doc = get_doc(action_or_method)
         return action_doc or view_doc
 
     def get_summary(self):
@@ -645,7 +644,7 @@ def _map_basic_serializer(self, serializer, direction):
         return build_object_type(
             properties=properties,
             required=required,
-            description=inspect.getdoc(serializer),
+            description=get_doc(serializer.__class__),
         )
 
     def _map_field_validators(self, field, schema):

drf_spectacular/plumbing.py

@@ -14,7 +14,9 @@
 from django import __version__ as DJANGO_VERSION
 from django.urls.resolvers import _PATH_PARAMETER_COMPONENT_RE, get_resolver  # type: ignore
 from django.utils.module_loading import import_string
-from rest_framework import exceptions, fields, serializers, versioning
+from rest_framework import (
+    exceptions, fields, generics, mixins, serializers, versioning, views, viewsets,
+)
 from uritemplate import URITemplate
 
 from drf_spectacular.settings import spectacular_settings
@@ -131,6 +133,40 @@ def get_override(obj, prop):
     return obj._spectacular_annotation[prop]
 
 
+def get_doc(obj):
+    """ get doc string with fallback on obj's base classes (ignoring DRF documentation). """
+    if not inspect.isclass(obj):
+        return inspect.getdoc(obj) or ''
+
+    def safe_index(lst, item):
+        try:
+            return lst.index(item)
+        except ValueError:
+            return float("inf")
+
+    lib_doc_excludes = [
+        serializers.Serializer,
+        serializers.ModelSerializer,
+        serializers.HyperlinkedModelSerializer,
+        viewsets.ModelViewSet,
+        viewsets.GenericViewSet,
+        viewsets.ViewSet,
+        viewsets.ReadOnlyModelViewSet,
+        generics.GenericAPIView,
+        mixins.ListModelMixin,
+        mixins.CreateModelMixin,
+        mixins.RetrieveModelMixin,
+        mixins.UpdateModelMixin,
+        mixins.DestroyModelMixin,
+        views.APIView,
+    ]
+    lib_barrier = min(safe_index(obj.__mro__, c) for c in lib_doc_excludes)
+    for cls in obj.__mro__[:lib_barrier]:
+        if cls.__doc__:
+            return inspect.cleandoc(cls.__doc__)
+    return ''
+
+
 def build_basic_type(obj):
     """
     resolve either enum or actual type and yield schema template for modification

tests/test_extensions.py

@@ -35,6 +35,7 @@ class XViewset(mixins.ListModelMixin, viewsets.GenericViewSet):
 class XView(APIView):
     """ underspecified library view """
     def get(self):
+        """ docstring for GET """
         return Response(1.234)  # pragma: no cover
 
 
@@ -53,6 +54,7 @@ def get(self, request):
     schema = generate_schema('x', view=XView)
     operation = schema['paths']['/x']['get']
     assert get_response_schema(operation)['type'] == 'number'
+    assert operation['description'].strip() == 'docstring for GET'
 
 
 @api_view()
@@ -72,3 +74,4 @@ def view_replacement(self):
     schema = generate_schema('x', view_function=x_view_function)
     operation = schema['paths']['/x']['get']
     assert get_response_schema(operation)['type'] == 'number'
+    assert operation['description'].strip() == 'underspecified library view'