WIP: AutoSchema: Inherit DRF AutoSchema

drf_spectacular/openapi.py

@@ -12,7 +12,7 @@
 from rest_framework import permissions, renderers, serializers
 from rest_framework.fields import _UnvalidatedField, empty
 from rest_framework.generics import GenericAPIView
-from rest_framework.schemas.inspectors import ViewInspector
+from rest_framework.schemas.openapi import AutoSchema as DRFAutoSchema
 from rest_framework.schemas.utils import get_pk_description
 from rest_framework.settings import api_settings
 from rest_framework.views import APIView
@@ -34,7 +34,7 @@
 from drf_spectacular.authentication import OpenApiAuthenticationExtension
 
 
-class AutoSchema(ViewInspector):
+class AutoSchema(DRFAutoSchema):
     method_mapping = {
         'get': 'retrieve',
         'post': 'create',
@@ -502,8 +502,9 @@ def _map_serializer_field(self, field):
             return content
 
         if isinstance(field, serializers.FileField):
-            # TODO returns filename. but does it accept binary data on upload?
-            return build_basic_type(OpenApiTypes.STR)
+            rv = build_basic_type(OpenApiTypes.STR)
+            rv['format'] = 'binary'
+            return rv
 
         if isinstance(field, serializers.SerializerMethodField):
             method = getattr(field.parent, field.method_name)
@@ -541,58 +542,44 @@ def _map_min_max(self, field, content):
         if field.min_value:
             content['minimum'] = field.min_value
 
-    def _map_serializer(self, serializer, direction):
+    def _map_serializer(self, serializer, direction=None):
         serializer = force_instance(serializer)
         serializer_extension = OpenApiSerializerExtension.get_match(serializer)
 
-        if serializer_extension:
+        if serializer_extension and direction:
             return serializer_extension.map_serializer(self, direction)
         else:
-            return self._map_basic_serializer(serializer, direction)
-
-    def _map_basic_serializer(self, serializer, direction):
-        required = []
-        properties = {}
-
-        for field in serializer.fields.values():
-            if isinstance(field, serializers.HiddenField):
-                continue
-
-            if field.required:
-                required.append(field.field_name)
-
-            schema = self._map_serializer_field(field)
-
-            if field.read_only:
-                schema['readOnly'] = True
-            if field.write_only:
-                schema['writeOnly'] = True
-            if field.allow_null:
-                schema['nullable'] = True
-            if field.default is not None and field.default != empty and not callable(field.default):
-                schema['default'] = field.to_representation(field.default)
-            if field.help_text:
-                schema['description'] = str(field.help_text)
-            self._map_field_validators(field, schema)
-
-            # sibling entries to $ref will be ignored as it replaces itself and its context with
-            # the referenced object. Wrap it in a separate context.
-            if '$ref' in schema and len(schema) > 1:
-                schema = {'allOf': [{'$ref': schema.pop('$ref')}], **schema}
-
-            properties[field.field_name] = schema
-
-        result = {
-            'type': 'object',
-            'properties': properties
-        }
-        if required and (self.method != 'PATCH' or direction == 'response'):
-            result['required'] = required
-
-        return result
+            if hasattr(DRFAutoSchema, 'map_serializer'):
+                result = super().map_serializer(serializer)
+            else:
+                result = super()._map_serializer(serializer)
+
+            if result.get('properties'):
+                # Move 'type' to top
+                new = {'type': 'object'}
+                new.update(result)
+                result = new
+
+                required = result.get('required')
+                if required and self.method == 'PATCH' and direction == 'request':
+                    del result['required']
+                elif required:
+                    # Move required to the end for DRF 3.10
+                    del result['required']
+                    result['required'] = required
+                elif required is not None:
+                    del result['required']
+
+            return result
 
     def _map_field_validators(self, field, schema):
-        for v in field.validators:
+        # DRF 3.10 'field' is the list of validators
+        if hasattr(field, 'validators'):
+            field_validators = field.validators
+        else:
+            field_validators = field
+
+        for v in field_validators:
             # https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.3.md#data-types
             if isinstance(v, validators.EmailValidator):
                 schema['format'] = 'email'
@@ -624,6 +611,69 @@ def _map_field_validators(self, field, schema):
                     schema['maximum'] = int(digits * '9') + 1
                     schema['minimum'] = -schema['maximum']
 
+        if schema.get('type') == 'array':
+            maxItems = schema.get('maxLength')
+            if maxItems:
+                del schema['maxLength']
+                schema['maxItems'] = maxItems
+            minItems = schema.get('minLength')
+            if minItems:
+                del schema['minLength']
+                schema['minItems'] = minItems
+
+    def _field_has_extra_metadata(self, field):
+        """Determine whether other metadata will be added after _map_field."""
+        if field.read_only:
+            return True
+        if field.write_only:
+            return True
+        if field.allow_null:
+            return True
+        if field.default and field.default != empty:  # why don't they use None?!
+            return True
+        if field.help_text:
+            return True
+
+    def _map_field(self, field):
+        schema = self._map_serializer_field(field)
+
+        if '$ref' in schema:
+            schema.pop('type', None)
+            if len(schema) > 1 or self._field_has_extra_metadata(field):
+                return {'allOf': [{'$ref': schema.pop('$ref')}], **schema}
+            return schema
+
+        try:
+            result = super()._map_field(field)
+        except RecursionError:
+            return schema
+
+        result.update(schema)
+        if result.get('properties'):
+            result['type'] = 'object'
+
+        # sibling entries to $ref will be ignored as it replaces itself and its context with
+        # the referenced object. Wrap it in a separate context.
+        if '$ref' in result:
+            result.pop('type', None)
+            if len(result) > 1 or self._field_has_extra_metadata(field):
+                return {'allOf': [{'$ref': result.pop('$ref')}], **result}
+            return result
+
+        new = {}
+        if result.get('enum'):
+            new['enum'] = result['enum']
+        if result.get('type'):
+            new['type'] = result['type']
+        if result.get('format'):
+            new['format'] = result['format']
+
+        new.update(result)
+
+        return new
+
+    map_field = _map_field
+
     def _map_type_hint(self, method):
         hint = getattr(method, '_spectacular_annotation', None) or typing.get_type_hints(method).get('return')
 

tests/test_fields.yml

@@ -161,8 +161,10 @@ components:
           minimum: -1000
         field_file:
           type: string
+          format: binary
         field_img:
           type: string
+          format: binary
         field_date:
           type: string
           format: date

tox.ini

@@ -19,7 +19,7 @@ ignore =
 max-line-length = 120
 
 [testenv]
-commands = ./runtests.py --fast --cov=drf_spectacular --cov=tests
+commands = ./runtests.py {posargs:--fast --cov=drf_spectacular --cov=tests}
 setenv =
        PYTHONDONTWRITEBYTECODE=1
 passenv =