Change schema_definition_x_property into schema_definition_extra_fields

flask_rest_api/spec/plugin.py

@@ -108,16 +108,12 @@ def flask_path_helper(spec, app, rule, operations=None, **kwargs):
     return path
 
 
-def schema_definition_x_property(spec, name, schema, **kwargs):
-    """Pass provided extensions properties as is to the spec
-
-       Extensions properties begin with 'x-'
-       http://swagger.io/specification/#vendorExtensions
-    """
-    return {k: v for k, v in kwargs.items() if k.startswith('x-')}
+def schema_definition_extra_fields(spec, name, schema, extra_fields=None):
+    """Add extra fields to the definition"""
+    return extra_fields or {}
 
 
 def setup(spec):
     """Setup for the plugin."""
     spec.register_path_helper(flask_path_helper)
-    spec.register_definition_helper(schema_definition_x_property)
+    spec.register_definition_helper(schema_definition_extra_fields)

tests/test_spec.py

@@ -0,0 +1,21 @@
+import pytest
+
+from marshmallow import Schema, fields
+
+from flask_rest_api import Api
+
+class TestSpec():
+
+    def test_schema_definition_extra_fields(self):
+
+        class MySchema(Schema):
+            field = fields.Str()
+
+        api = Api()
+        api.definition('MySchema')(
+            Schema,
+            extra_fields={'test': 'ok', 'x-test': 'check, check!'})
+
+        schema_def = api._apispec.spec.to_dict()['definitions']['MySchema']
+        assert schema_def['test'] == 'ok'
+        assert schema_def['x-test'] == 'check, check!'