Merge pull request #280 from mozilla-services/preserve-schemas

Preserve values if colander has unknown="preserve".

cornice/schemas.py

@@ -96,6 +96,9 @@ def validate_colander_schema(schema, request):
     """Validates that the request is conform to the given schema"""
     from colander import Invalid, Sequence, drop, null, MappingSchema
 
+    schema_type = schema.colander_schema.schema_type()
+    unknown = getattr(schema_type, 'unknown', None)
+
     if not isinstance(schema.colander_schema, MappingSchema):
         raise SchemaError('schema is not a MappingSchema: %s' %
                           type(schema.colander_schema))
@@ -150,6 +153,11 @@ def _validate_fields(location, data):
                     if deserialized is not drop:
                         request.validated[attr.name] = deserialized
 
+        if location == "body" and unknown == 'preserve':
+            for field, value in data.items():
+                if field not in request.validated:
+                    request.validated[field] = value
+
     qs, headers, body, path = extract_request_data(request)
 
     _validate_fields('path', path)

cornice/tests/test_schemas.py

@@ -7,6 +7,7 @@
     CorniceSchema, validate_colander_schema, SchemaError
 )
 from cornice.util import extract_json_data
+import json
 
 try:
     from colander import (
@@ -106,6 +107,12 @@ class TestingSchemaWithHeader(MappingSchema):
         baz = SchemaNode(String(), type='str', location="querystring")
         qux = SchemaNode(String(), type='str', location="header")
 
+    class PreserveUnkownSchema(MappingSchema):
+        bar = SchemaNode(String(), type='str')
+
+        def schema_type(self, **kw):
+            return Mapping(unknown='preserve')
+
     def get_mock_request(body, get=None):
         # Construct a mock request with the given request body
         class MockRegistry(object):
@@ -349,3 +356,16 @@ def test_extra_params_qs_strict(self):
 
             expected = {'foo': 'test'}
             self.assertEqual(expected, dummy_request.validated)
+
+        def test_validate_colander_schema_can_preserve_unknown_fields(self):
+            schema = CorniceSchema.from_colander(PreserveUnkownSchema)
+
+            data = json.dumps({"bar": "required_data", "optional": "true"})
+            dummy_request = get_mock_request(data)
+            validate_colander_schema(schema, dummy_request)
+
+            self.assertDictEqual(dummy_request.validated, {
+                "bar": "required_data",
+                "optional": "true"
+            })
+            self.assertEqual(len(dummy_request.errors), 0)