Use jsonschema for validation (#936)

* jsonschema validation

* doh, exceptions should be raised

* internalize OpenAPI specs

from 6d17b631ff

* enforce that each default value validates against the schema in which it resides

* Fix import order

* Remove unused imports

* Move _validate_spec() to Specification base class

Co-authored-by: Patrick Wang <patrickkwang@users.noreply.github.com>

MANIFEST.in

@@ -1,2 +1,3 @@
 include *.txt
 include *.rst
+recursive-include connexion/resources *.json

connexion/spec.py

@@ -4,19 +4,54 @@ This module defines Python interfaces for OpenAPI specifications.
 
 import abc
 import copy
+import json
 import pathlib
 from collections.abc import Mapping
 from urllib.parse import urlsplit
 
 import jinja2
+import jsonschema
+import pkg_resources
 import yaml
-from openapi_spec_validator.exceptions import OpenAPIValidationError
+from jsonschema import Draft4Validator
+from jsonschema.validators import extend as extend_validator
 
 from .exceptions import InvalidSpecification
 from .json_schema import resolve_refs
 from .operations import OpenAPIOperation, Swagger2Operation
 from .utils import deep_get
 
+validate_properties = Draft4Validator.VALIDATORS["properties"]
+
+
+def validate_defaults(validator, properties, instance, schema):
+    """Validate `properties` subschema.
+
+    Enforcing each default value validates against the schema in which it resides.
+    """
+    valid = True
+    for error in validate_properties(
+        validator, properties, instance, schema,
+    ):
+        valid = False
+        yield error
+
+    # Validate default only when the subschema has validated successfully
+    # and only when an instance validator is available.
+    if not valid or not hasattr(validator, 'instance_validator'):
+        return
+    if isinstance(instance, dict) and 'default' in instance:
+        for error in validator.instance_validator.iter_errors(
+            instance['default'],
+            instance
+        ):
+            yield error
+
+
+OpenApiValidator = extend_validator(
+    Draft4Validator, {"properties": validate_defaults},
+)
+
 NO_SPEC_VERSION_ERR_MSG = """Unable to get the spec version.
 You are missing either '"swagger": "2.0"' or '"openapi": "3.0.0"'
 from the top level of your spec."""
@@ -44,10 +79,15 @@ class Specification(Mapping):
         """
 
     @classmethod
-    @abc.abstractmethod
     def _validate_spec(cls, spec):
         """ validate spec against schema
         """
+        try:
+            validator = OpenApiValidator(cls.openapi_schema)
+            validator.instance_validator = Draft4Validator(spec)
+            validator.validate(spec)
+        except jsonschema.exceptions.ValidationError as e:
+            raise InvalidSpecification.create_from(e)
 
     def get_path_params(self, path):
         return deep_get(self._spec, ["paths", path]).get("parameters", [])
@@ -164,6 +204,9 @@ class Swagger2Specification(Specification):
     yaml_name = 'swagger.yaml'
     operation_cls = Swagger2Operation
 
+    schema_string = pkg_resources.resource_string('connexion', 'resources/schemas/v2.0/schema.json')
+    openapi_schema = json.loads(schema_string.decode('utf-8'))
+
     @classmethod
     def _set_defaults(cls, spec):
         spec.setdefault('produces', [])
@@ -206,14 +249,6 @@ class Swagger2Specification(Specification):
         self._raw_spec['basePath'] = base_path
         self._spec['basePath'] = base_path
 
-    @classmethod
-    def _validate_spec(cls, spec):
-        from openapi_spec_validator import validate_v2_spec as validate_spec
-        try:
-            validate_spec(spec)
-        except OpenAPIValidationError as e:
-            raise InvalidSpecification.create_from(e)
-
 
 class OpenAPISpecification(Specification):
     """Python interface for an OpenAPI 3 specification."""
@@ -221,6 +256,9 @@ class OpenAPISpecification(Specification):
     yaml_name = 'openapi.yaml'
     operation_cls = OpenAPIOperation
 
+    schema_string = pkg_resources.resource_string('connexion', 'resources/schemas/v3.0/schema.json')
+    openapi_schema = json.loads(schema_string.decode('utf-8'))
+
     @classmethod
     def _set_defaults(cls, spec):
         spec.setdefault('components', {})
@@ -233,14 +271,6 @@ class OpenAPISpecification(Specification):
     def components(self):
         return self._spec['components']
 
-    @classmethod
-    def _validate_spec(cls, spec):
-        from openapi_spec_validator import validate_v3_spec as validate_spec
-        try:
-            validate_spec(spec)
-        except OpenAPIValidationError as e:
-            raise InvalidSpecification.create_from(e)
-
     @property
     def base_path(self):
         servers = self._spec.get('servers', [])