Merge pull request spec-first#186 from dfeinzeig/feature/issue-153-de…

…tails-of-response-validation

Better error handling for non-conforming responses

connexion/api.py

@@ -16,8 +16,10 @@
 import json
 import logging
 import pathlib
-import yaml
+import six
+import sys
 import werkzeug.exceptions
+import yaml
 from swagger_spec_validator.validator20 import validate_spec
 from .operation import Operation
 from . import utils
@@ -181,10 +183,8 @@ def add_paths(self, paths=None):
                     if self.debug:
                         logger.exception(error_msg)
                     else:
-                        import sys
                         logger.error(error_msg)
-                        et, ei, tb = sys.exc_info()
-                        raise ei.with_traceback(tb)
+                        six.reraise(*sys.exc_info())
 
     def add_auth_on_not_found(self):
         """

connexion/decorators/response.py

@@ -14,10 +14,11 @@
 # Decorators to change the return type of endpoints
 import functools
 import logging
-from ..exceptions import NonConformingResponse
+from ..exceptions import NonConformingResponseBody, NonConformingResponseHeaders
 from ..problem import problem
-from .validation import RequestBodyValidator
+from .validation import ResponseBodyValidator
 from .decorator import BaseDecorator
+from jsonschema import ValidationError
 
 
 logger = logging.getLogger('connexion.decorators.response')
@@ -48,14 +49,18 @@ def validate_response(self, data, status_code, headers):
 
         if response_definition and response_definition.get("schema"):
             schema = response_definition.get("schema")
-            v = RequestBodyValidator(schema)
-            error = v.validate_schema(data)
-            if error:
-                raise NonConformingResponse("Response body does not conform to specification")
+            v = ResponseBodyValidator(schema)
+            try:
+                v.validate_schema(data)
+            except ValidationError as e:
+                raise NonConformingResponseBody(message=str(e))
 
         if response_definition and response_definition.get("headers"):
-            if not all(item in headers.keys() for item in response_definition.get("headers").keys()):
-                raise NonConformingResponse("Response headers do not conform to specification")
+            response_definition_header_keys = response_definition.get("headers").keys()
+            if not all(item in headers.keys() for item in response_definition_header_keys):
+                raise NonConformingResponseHeaders(
+                    message="Keys in header don't match response specification. Difference: %s"
+                    % list(set(headers.keys()).symmetric_difference(set(response_definition_header_keys))))
         return True
 
     def __call__(self, function):
@@ -69,8 +74,10 @@ def wrapper(*args, **kwargs):
             try:
                 data, status_code, headers = self.get_full_response(result)
                 self.validate_response(data, status_code, headers)
-            except NonConformingResponse as e:
-                return problem(500, 'Internal Server Error', e.reason)
+            except NonConformingResponseBody as e:
+                return problem(500, e.reason, e.message)
+            except NonConformingResponseHeaders as e:
+                return problem(500, e.reason, e.message)
             return result
 
         return wrapper

connexion/decorators/validation.py

@@ -16,6 +16,8 @@
 import functools
 import itertools
 import logging
+import six
+import sys
 from jsonschema import draft4_format_checker, validate, ValidationError
 
 from ..problem import problem
@@ -117,11 +119,35 @@ def validate_schema(self, data):
         try:
             validate(data, self.schema, format_checker=draft4_format_checker)
         except ValidationError as exception:
+            logger.error("%s validation error: %s" % (flask.request.url, exception))
             return problem(400, 'Bad Request', str(exception))
 
         return None
 
 
+class ResponseBodyValidator(object):
+    def __init__(self, schema, has_default=False):
+        """
+        :param schema: The schema of the response body
+        :param has_default: Flag to indicate if default value is present.
+        """
+        self.schema = schema
+        self.has_default = schema.get('default', has_default)
+
+    def validate_schema(self, data):
+        """
+        :type schema: dict
+        :rtype: flask.Response | None
+        """
+        try:
+            validate(data, self.schema, format_checker=draft4_format_checker)
+        except ValidationError as exception:
+            logger.error("%s validation error: %s" % (flask.request.url, exception))
+            six.reraise(*sys.exc_info())
+
+        return None
+
+
 class ParameterValidator(object):
     def __init__(self, parameters):
         self.parameters = {k: list(g) for k, g in itertools.groupby(parameters, key=lambda p: p['in'])}

connexion/exceptions.py

@@ -32,15 +32,26 @@ def __repr__(self):  # pragma: no cover
 
 
 class NonConformingResponse(ConnexionException):
-    def __init__(self, reason='Unknown Reason'):
+    def __init__(self, reason='Unknown Reason', message=None):
         """
         :param reason: Reason why the response did not conform to the specification
         :type reason: str
         """
         self.reason = reason
+        self.message = message
 
     def __str__(self):  # pragma: no cover
         return '<NonConformingResponse: {}>'.format(self.reason)
 
     def __repr__(self):  # pragma: no cover
         return '<NonConformingResponse: {}>'.format(self.reason)
+
+
+class NonConformingResponseBody(NonConformingResponse):
+    def __init__(self, message, reason="Response body does not conform to specification"):
+        super(NonConformingResponseBody, self).__init__(reason=reason, message=message)
+
+
+class NonConformingResponseHeaders(NonConformingResponse):
+    def __init__(self, message, reason="Response headers do not conform to specification"):
+        super(NonConformingResponseHeaders, self).__init__(reason=reason, message=message)

tests/api/test_headers.py

@@ -25,8 +25,8 @@ def test_header_not_returned(simple_app):
     assert response.content_type == 'application/problem+json'
     data = json.loads(response.data.decode('utf-8'))
     assert data['type'] == 'about:blank'
-    assert data['title'] == 'Internal Server Error'
-    assert data['detail'] == 'Response headers do not conform to specification'
+    assert data['title'] == 'Response headers do not conform to specification'
+    assert data['detail'] == "Keys in header don't match response specification. Difference: ['Location']"
     assert data['status'] == 500