Fixed issue #314 - include information about view/serializer in warnings

drf_spectacular/drainage.py

@@ -1,3 +1,4 @@
+import contextlib
 import sys
 from collections import defaultdict
 from typing import DefaultDict
@@ -20,7 +21,7 @@ def emit(self, msg, severity):
         if spectacular_settings.DISABLE_ERRORS_AND_WARNINGS:
             return
         assert severity in ['warning', 'error']
-        msg = str(msg)
+        msg = _get_current_trace() + str(msg)
         cache = self._warn_cache if severity == 'warning' else self._error_cache
         if msg not in cache:
             print(f'{severity.capitalize()} #{len(cache)}: {msg}', file=sys.stderr)
@@ -51,6 +52,23 @@ def reset_generator_stats():
     GENERATOR_STATS.reset()
 
 
+_TRACES = []
+
+
+@contextlib.contextmanager
+def add_trace_message(trace_message):
+    """
+    Adds a message to be used as a prefix when emitting warnings and errors.
+    """
+    _TRACES.append(trace_message)
+    yield
+    _TRACES.pop()
+
+
+def _get_current_trace():
+    return ''.join(f"{trace}: " for trace in _TRACES if trace)
+
+
 def has_override(obj, prop):
     if not hasattr(obj, '_spectacular_annotation'):
         return False

drf_spectacular/hooks.py

@@ -82,15 +82,15 @@ def create_enum_component(name, schema):
                 enum_name = f'{camelize(prop_name)}{prop_hash[:3].capitalize()}Enum'
                 warn(
                     f'enum naming encountered a non-optimally resolvable collision for fields '
-                    f'named "{prop_name}". the same name has been used for multiple choice sets '
-                    f'in multiple components. the collision was resolved with "{enum_name}". '
+                    f'named "{prop_name}". The same name has been used for multiple choice sets '
+                    f'in multiple components. The collision was resolved with "{enum_name}". '
                     f'add an entry to ENUM_NAME_OVERRIDES to fix the naming.'
                 )
             if enum_name_mapping.get(prop_hash, enum_name) != enum_name:
                 warn(
-                    f'encountered multiple names for the same choice set ({enum_name}). this '
+                    f'encountered multiple names for the same choice set ({enum_name}). This '
                     f'may be unwanted even though the generated schema is technically correct. '
-                    f'add an entry to ENUM_NAME_OVERRIDES to fix the naming.'
+                    f'Add an entry to ENUM_NAME_OVERRIDES to fix the naming.'
                 )
                 del enum_name_mapping[prop_hash]
             else:

drf_spectacular/openapi.py

@@ -18,7 +18,7 @@
 
 from drf_spectacular.authentication import OpenApiAuthenticationExtension
 from drf_spectacular.contrib import *  # noqa: F403, F401
-from drf_spectacular.drainage import get_override, has_override
+from drf_spectacular.drainage import add_trace_message, get_override, has_override
 from drf_spectacular.extensions import (
     OpenApiFilterExtension, OpenApiSerializerExtension, OpenApiSerializerFieldExtension,
 )
@@ -161,7 +161,7 @@ def _process_override_parameters(self):
                         required=property_name in mapped.get('required', []),
                     )
             else:
-                warn(f'could not resolve parameter annotation {parameter}. skipping.')
+                warn(f'could not resolve parameter annotation {parameter}. Skipping.')
         return result
 
     def _get_format_parameters(self):
@@ -324,10 +324,10 @@ def _resolve_path_parameters(self, variables):
                 schema = resolved_parameter['schema']
             elif get_view_model(self.view) is None:
                 warn(
-                    f'could not derive type of path parameter "{variable}" because because it '
-                    f'is untyped and obtaining queryset from {self.view.__class__} failed. '
-                    f'consider adding a type to the path (e.g. <int:{variable}>) or annotating '
-                    f'the parameter type with @extend_schema. defaulting to "string".'
+                    f'{self.view.__class__.__name__}: could not derive type of path parameter '
+                    f'"{variable}" because it is untyped and obtaining queryset from the viewset '
+                    f'failed. Consider adding a type to the path (e.g. <int:{variable}>) or '
+                    f'annotating the parameter type with @extend_schema. Defaulting to "string".'
                 )
             else:
                 try:
@@ -338,9 +338,10 @@ def _resolve_path_parameters(self, variables):
                         description = get_pk_description(model, model_field)
                 except django_exceptions.FieldDoesNotExist:
                     warn(
-                        f'could not derive type of path parameter "{variable}" because '
-                        f'model "{model}" did contain no such field. consider annotating '
-                        f'parameter with @extend_schema. defaulting to "string".'
+                        f'{self.view.__class__.__name__}: could not derive type of path '
+                        f'parameter "{variable}" for view  because '
+                        f'model "{model}" did contain no such field. Consider annotating '
+                        f'parameter with @extend_schema. Defaulting to "string".'
                     )
 
             parameters.append(build_parameter_type(
@@ -417,15 +418,15 @@ def _map_model_field(self, model_field, direction):
             if not field_cls:
                 warn(
                     f'model field "{model_field.get_internal_type()}" has no mapping in '
-                    f'ModelSerializer. it may be a deprecated field. defaulting to "string"'
+                    f'ModelSerializer. It may be a deprecated field. Defaulting to "string"'
                 )
                 return build_basic_type(OpenApiTypes.STR)
             return self._map_serializer_field(field_cls(), direction)
         else:
             error(
-                f'could not resolve model field "{model_field}". failed to resolve through '
+                f'could not resolve model field "{model_field}". Failed to resolve through '
                 f'serializer_field_mapping, get_internal_type(), or any override mechanism. '
-                f'defaulting to "string"'
+                f'Defaulting to "string"'
             )
             return build_basic_type(OpenApiTypes.STR)
 
@@ -642,7 +643,7 @@ def _map_serializer_field(self, field, direction):
             schema = self._map_model_field(field.model_field, direction)
             return append_meta(schema, meta)
 
-        warn(f'could not resolve serializer field "{field}". defaulting to "string"')
+        warn(f'could not resolve serializer field "{field}". Defaulting to "string"')
         return append_meta(build_basic_type(OpenApiTypes.STR), meta)
 
     def _map_min_max(self, field, content):
@@ -794,8 +795,8 @@ def _map_response_type_hint(self, method):
             return resolve_type_hint(hint)
         except UnableToProceedError:
             warn(
-                f'unable to resolve type hint for function "{method.__name__}". consider '
-                f'using a type hint or @extend_schema_field. defaulting to string.'
+                f'unable to resolve type hint for function "{method.__name__}". Consider '
+                f'using a type hint or @extend_schema_field. Defaulting to string.'
             )
             return build_basic_type(OpenApiTypes.STR)
 
@@ -835,15 +836,15 @@ def _get_serializer(self):
                     return view.serializer_class
                 else:
                     error(
-                        f'Unable to guess serializer for {view.__class__.__name__}. This is graceful '
+                        f'{view.__class__.__name__}: unable to guess serializer. This is graceful '
                         f'fallback handling for APIViews. Consider using GenericAPIView as view base '
-                        f'class, if view is under your control. ignoring view for now. '
+                        f'class, if view is under your control. Ignoring view for now. '
                     )
             else:
-                error('Encountered unknown view base class. please report this issue. ignoring for now')
+                error('Encountered unknown view base class. Please report this issue. Ignoring for now')
         except Exception as exc:
             error(
-                f'Exception raised while getting serializer from {view.__class__.__name__}. Hint: '
+                f'exception raised while getting serializer. Hint: '
                 f'Is get_serializer_class() returning None or is get_queryset() not working without '
                 f'a request? Ignoring the view for now. (Exception: {exc})'
             )
@@ -939,8 +940,8 @@ def _get_request_for_media_type(self, serializer):
             request_body_required = False
         else:
             warn(
-                f'could not resolve request body for {self.method} {self.path}. defaulting to generic '
-                'free-form object. (maybe annotate a Serializer class?)'
+                f'could not resolve request body for {self.method} {self.path}. Defaulting to generic '
+                'free-form object. (Maybe annotate a Serializer class?)'
             )
             schema = build_generic_type()
             schema['description'] = 'Unspecified request body'
@@ -974,7 +975,7 @@ def _get_response_bodies(self):
             warn(
                 f'could not resolve "{response_serializers}" for {self.method} {self.path}. '
                 f'Expected either a serializer or some supported override mechanism. '
-                f'defaulting to generic free-form object.'
+                f'Defaulting to generic free-form object.'
             )
             schema = build_basic_type(OpenApiTypes.OBJECT)
             schema['description'] = _('Unspecified response body')
@@ -1005,7 +1006,7 @@ def _get_response_for_code(self, serializer, status_code, media_types=None):
         else:
             warn(
                 f'could not resolve "{serializer}" for {self.method} {self.path}. Expected either '
-                f'a serializer or some supported override mechanism. defaulting to '
+                f'a serializer or some supported override mechanism. Defaulting to '
                 f'generic free-form object.'
             )
             schema = build_basic_type(OpenApiTypes.OBJECT)
@@ -1123,27 +1124,27 @@ def resolve_serializer(self, serializer, direction) -> ResolvedComponent:
             f'https://github.com/tfranzel/drf-spectacular/issues '
         )
         serializer = force_instance(serializer)
-
-        component = ResolvedComponent(
-            name=self._get_serializer_name(serializer, direction),
-            type=ResolvedComponent.SCHEMA,
-            object=serializer,
-        )
-        if component in self.registry:
-            return self.registry[component]  # return component with schema
-
-        self.registry.register(component)
-        component.schema = self._map_serializer(serializer, direction)
-        # 4 cases:
-        #   1. polymorphic container component -> use
-        #   2. concrete component with properties -> use
-        #   3. concrete component without properties -> prob. transactional so discard
-        #   4. explicit list component -> demultiplexed at usage location so discard
-        keep_component = (
-            any(nest_tag in component.schema for nest_tag in ['oneOf', 'allOf', 'anyOf'])
-            or component.schema.get('properties', {})
-        )
-        if not keep_component:
-            del self.registry[component]
-            return ResolvedComponent(None, None)  # sentinel
-        return component
+        with add_trace_message(serializer.__class__.__name__):
+            component = ResolvedComponent(
+                name=self._get_serializer_name(serializer, direction),
+                type=ResolvedComponent.SCHEMA,
+                object=serializer,
+            )
+            if component in self.registry:
+                return self.registry[component]  # return component with schema
+
+            self.registry.register(component)
+            component.schema = self._map_serializer(serializer, direction)
+            # 4 cases:
+            #   1. polymorphic container component -> use
+            #   2. concrete component with properties -> use
+            #   3. concrete component without properties -> prob. transactional so discard
+            #   4. explicit list component -> demultiplexed at usage location so discard
+            keep_component = (
+                any(nest_tag in component.schema for nest_tag in ['oneOf', 'allOf', 'anyOf'])
+                or component.schema.get('properties', {})
+            )
+            if not keep_component:
+                del self.registry[component]
+                return ResolvedComponent(None, None)  # sentinel
+            return component

drf_spectacular/plumbing.py

@@ -119,9 +119,9 @@ def get_view_model(view):
         return view.get_queryset().model
     except Exception as exc:
         warn(
-            f'failed to obtain model through view\'s queryset due to raised exception. '
-            f'prevent this either by setting "queryset = Model.objects.none()" on the view, '
-            f'having an empty fallback in get_queryset() or by using @extend_schema. '
+            f'{view.__class__.__name__}: failed to obtain model through view\'s queryset due to '
+            f'raised exception. Prevent this either by setting "queryset = Model.objects.none()" '
+            f'on the view, having an empty fallback in get_queryset() or by using @extend_schema. '
             f'(Exception: {exc})'
         )
 
@@ -389,8 +389,8 @@ def follow_field_source(model, path):
     except Exception as exc:
         warn(
             f'could not resolve field on model {model} with path "{".".join(path)}". '
-            f'this is likely a custom field that does some unknown magic. maybe '
-            f'consider annotating the field/property? defaulting to "string". (Exception: {exc})'
+            f'This is likely a custom field that does some unknown magic. Maybe '
+            f'consider annotating the field/property? Defaulting to "string". (Exception: {exc})'
         )
 
     def dummy_property(obj) -> str:
@@ -581,8 +581,8 @@ def load_enum_name_overrides():
 
     if len(spectacular_settings.ENUM_NAME_OVERRIDES) != len(overrides):
         error(
-            'ENUM_NAME_OVERRIDES has duplication issues. encountered multiple names '
-            'for the same choice set. enum naming might be unexpected.'
+            'ENUM_NAME_OVERRIDES has duplication issues. Encountered multiple names '
+            'for the same choice set. Enum naming might be unexpected.'
         )
     return overrides
 
@@ -660,7 +660,7 @@ def modify_for_versioning(patterns, method, path, view, requested_version):
                 urlconf=tuple(detype_pattern(p) for p in patterns)
             ).resolve(path)
         except Resolver404:
-            error(f"namespace versioning path resolution failed for {path}. path will be ignored.")
+            error(f"namespace versioning path resolution failed for {path}. Path will be ignored.")
     elif issubclass(view.versioning_class, versioning.AcceptHeaderVersioning):
         # Append the version into request accepted_media_type.
         # e.g "application/json; version=1.0"

tests/__init__.py

@@ -20,7 +20,7 @@ def assert_schema(schema, reference_filename, transforms=None):
 
     if not os.path.exists(reference_filename):
         raise RuntimeError(
-            f'{reference_filename} was not found for comparison. carefully inspect '
+            f'{reference_filename} was not found for comparison. Carefully inspect '
             f'the generated {reference_filename.replace(".yml", "_out.yml")} and '
             f'copy it to {reference_filename} to serve as new ground truth.'
         )
@@ -51,23 +51,29 @@ def generate_schema(route, viewset=None, view=None, view_function=None):
     from rest_framework import routers
     from rest_framework.viewsets import ViewSetMixin
 
+    from drf_spectacular.drainage import add_trace_message
     from drf_spectacular.generators import SchemaGenerator
 
     patterns = []
+    trace_message = ''
     if viewset:
         assert issubclass(viewset, ViewSetMixin)
         router = routers.SimpleRouter()
         router.register(route, viewset, basename=route)
         patterns = router.urls
+        trace_message = viewset.__name__
     elif view:
         patterns = [path(route, view.as_view())]
+        trace_message = view.__name__
     elif view_function:
         patterns = [path(route, view_function)]
+        trace_message = view_function.__name__
 
-    generator = SchemaGenerator(patterns=patterns)
-    schema = generator.get_schema(request=None, public=True)
-    validate_schema(schema)  # make sure generated schemas are always valid
-    return schema
+    with add_trace_message(trace_message):
+        generator = SchemaGenerator(patterns=patterns)
+        schema = generator.get_schema(request=None, public=True)
+        validate_schema(schema)  # make sure generated schemas are always valid
+        return schema
 
 
 def get_response_schema(operation, status=None, content_type='application/json'):

tests/test_command.py

@@ -49,5 +49,5 @@ def test_command_fail(capsys):
             '--urlconf=tests.test_command',
         )
     stderr = capsys.readouterr().err
-    assert 'Error #0: Unable to guess serializer' in stderr
+    assert 'Error #0: func: unable to guess serializer' in stderr
     assert 'Schema generation summary:' in stderr