Improve validator error handling

README.rst

@@ -126,7 +126,7 @@ In ``urls.py``:
          contact=openapi.Contact(email="contact@snippets.local"),
          license=openapi.License(name="BSD License"),
       ),
-      validators=['ssv', 'flex'],
+      validators=['flex', 'ssv'],
       public=True,
       permission_classes=(permissions.AllowAny,),
    )
@@ -267,7 +267,7 @@ caching the schema view in-memory, with some sane defaults:
 
 Given the numerous methods to manually customzie the generated schema, it makes sense to validate the result to ensure
 it still conforms to OpenAPI 2.0. To this end, validation is provided at the generation point using python swagger
-libraries, and can be activated by passing :python:`validators=['ssv', 'flex']` to ``get_schema_view``; if the generated
+libraries, and can be activated by passing :python:`validators=['flex', 'ssv']` to ``get_schema_view``; if the generated
 schema is not valid, a :python:`SwaggerValidationError` is raised by the handling codec.
 
 **Warning:** This internal validation can slow down your server.

src/drf_yasg/codecs.py

@@ -12,22 +12,22 @@ from .app_settings import swagger_settings
 from .errors import SwaggerValidationError
 
 
-def _validate_flex(spec, codec):
+def _validate_flex(spec):
     from flex.core import parse as validate_flex
     from flex.exceptions import ValidationError
     try:
         validate_flex(spec)
     except ValidationError as ex:
-        raise_from(SwaggerValidationError(str(ex), 'flex', spec, codec), ex)
+        raise_from(SwaggerValidationError(str(ex)), ex)
 
 
-def _validate_swagger_spec_validator(spec, codec):
+def _validate_swagger_spec_validator(spec):
     from swagger_spec_validator.validator20 import validate_spec as validate_ssv
     from swagger_spec_validator.common import SwaggerValidationError as SSVErr
     try:
         validate_ssv(spec)
     except SSVErr as ex:
-        raise_from(SwaggerValidationError(str(ex), 'swagger_spec_validator', spec, codec), ex)
+        raise_from(SwaggerValidationError(str(ex)), ex)
 
 
 #:
@@ -61,10 +61,17 @@ class _OpenAPICodec(object):
             raise TypeError('Expected a `openapi.Swagger` instance')
 
         spec = self.generate_swagger_object(document)
+        errors = {}
         for validator in self.validators:
+            try:
                 # validate a deepcopy of the spec to prevent the validator from messing with it
                 # for example, swagger_spec_validator adds an x-scope property to all references
-            VALIDATORS[validator](copy.deepcopy(spec), self)
+                VALIDATORS[validator](copy.deepcopy(spec))
+            except SwaggerValidationError as e:
+                errors[validator] = str(e)
+
+        if errors:
+            raise SwaggerValidationError("spec validation failed", errors, spec, self)
         return force_bytes(self._dump_dict(spec))
 
     def encode_error(self, err):

src/drf_yasg/errors.py

@@ -3,9 +3,9 @@ class SwaggerError(Exception):
 
 
 class SwaggerValidationError(SwaggerError):
-    def __init__(self, msg, validator_name, spec, source_codec, *args):
+    def __init__(self, msg, errors=None, spec=None, source_codec=None, *args):
         super(SwaggerValidationError, self).__init__(msg, *args)
-        self.validator_name = validator_name
+        self.errors = errors
         self.spec = spec
         self.source_codec = source_codec
 

src/drf_yasg/middleware.py

@@ -13,7 +13,7 @@ class SwaggerExceptionMiddleware(object):
 
     def process_exception(self, request, exception):
         if isinstance(exception, SwaggerValidationError):
-            err = {'errors': {exception.validator_name: str(exception)}}
+            err = {'errors': exception.errors, 'message': str(exception)}
             codec = exception.source_codec
             if isinstance(codec, _OpenAPICodec):
                 err = codec.encode_error(err)

src/drf_yasg/renderers.py

@@ -9,7 +9,7 @@ from .codecs import VALIDATORS, OpenAPICodecJson, OpenAPICodecYaml
 class _SpecRenderer(BaseRenderer):
     """Base class for text renderers. Handles encoding and validation."""
     charset = None
-    validators = ['ssv', 'flex']
+    validators = []
     codec_class = None
 
     @classmethod

src/drf_yasg/views.py

@@ -12,8 +12,9 @@ from rest_framework.views import APIView
 
 from .app_settings import swagger_settings
 from .generators import OpenAPISchemaGenerator
-from .renderers import OpenAPIRenderer, ReDocRenderer, SwaggerJSONRenderer, SwaggerUIRenderer, SwaggerYAMLRenderer, \
-    ReDocAlphaRenderer
+from .renderers import (
+    OpenAPIRenderer, ReDocAlphaRenderer, ReDocRenderer, SwaggerJSONRenderer, SwaggerUIRenderer, SwaggerYAMLRenderer
+)
 
 SPEC_RENDERERS = (SwaggerYAMLRenderer, SwaggerJSONRenderer, OpenAPIRenderer)
 UI_RENDERERS = {