Fix enum without explicit type rendering as null (issue #64)

When a schema uses 'enum' without a 'type' field (valid JSON Schema),
get_example_from_schema fell through to 'return None' because there was
no type to dispatch to a ScalarExampleHandler. The enum check in
ScalarExampleHandler.get_example was never reached.

Fix: add an early enum check in get_example_from_schema itself, after
the 'examples' check and before the type dispatch, so typeless enums
also return their first value.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: RobertoPrevato

openapidocs/mk/v3/examples.py

@@ -140,6 +140,11 @@ def get_example_from_schema(schema) -> Any:
     if isinstance(examples, list) and examples:
         return examples[0]
 
+    # enum without explicit type - return the first value directly
+    enum = schema.get("enum")
+    if isinstance(enum, list) and enum:
+        return enum[0]
+
     # does it have a type?
     handlers_types: List[Type[SchemaExampleHandler]] = list(
         get_subclasses(SchemaExampleHandler)

tests/test_oas31.py

@@ -187,6 +187,9 @@ class TestGetExampleFromSchemaAnnotations:
             ({"type": "boolean", "enum": [False]}, False),
             # enum on string (pre-existing behaviour still works)
             ({"type": "string", "enum": ["active", "inactive"]}, "active"),
+            # enum without explicit type (valid JSON Schema)
+            ({"enum": ["active", "inactive"]}, "active"),
+            ({"enum": [1, 2, 3]}, 1),
         ],
     )
     def test_examples_and_enum(self, schema, expected):