Merge pull request #3995 from open-formulieren/issue/3688-no-spec

[#3688] Fix issue when no JSON Schema spec is provided

src/openforms/registrations/contrib/objects_api/json_schema.py

@@ -7,7 +7,7 @@
 from jsonschema_specifications import REGISTRY
 from referencing import Resource
 from referencing.exceptions import Unresolvable
-from referencing.jsonschema import ObjectSchema
+from referencing.jsonschema import DRAFT202012, ObjectSchema
 from typing_extensions import Self
 
 
@@ -68,7 +68,7 @@ def iter_json_schema_paths(
     Known to be unsupported:
     - Composition (https://json-schema.org/understanding-json-schema/reference/combining)
     """
-    resource = Resource.from_contents(json_schema)
+    resource = Resource.from_contents(json_schema, default_specification=DRAFT202012)
     # Or referencing.jsonschema.EMPTY_REGISTRY?
     resolver = REGISTRY.resolver_with_root(resource)
 

src/openforms/registrations/contrib/objects_api/tests/test_json_schema.py

@@ -8,6 +8,8 @@
     json_schema_matches,
 )
 
+JSON_SCHEMA_NO_SPEC = {"type": "object", "properties": {"prop": {"type": "string"}}}
+
 JSON_SCHEMA_NO_REFS = {
     "$id": "noise-complaint.schema",
     "$schema": "http://json-schema.org/draft-07/schema#",
@@ -163,6 +165,12 @@ class IterJsonSchemaTests(SimpleTestCase):
     simply be tested as ``([], CURRENT_SCHEMA_TESTED)``.
     """
 
+    def test_no_spec_default(self):
+        try:
+            list(iter_json_schema_paths(JSON_SCHEMA_NO_SPEC))
+        except Exception as e:
+            raise self.failureException("Unexpected exception") from e
+
     def test_iter_json_schema_no_refs(self):
         paths_list = [
             (path.segments, schema)