fix: schema inferrer supports more than two types (#830)

Author: maxi297

airbyte_cdk/utils/schema_inferrer.py

@@ -120,7 +120,7 @@ def _clean_any_of(self, node: InferredSchema) -> None:
             node[_TYPE] = [node[_TYPE], _NULL_TYPE]
             node.pop(_ANY_OF)
         # populate `type` for `anyOf` if it's not present to pass all other checks
-        elif len(node[_ANY_OF]) == 2 and not self._null_type_in_any_of(node):
+        elif len(node[_ANY_OF]) > 1:
             node[_TYPE] = [_NULL_TYPE]
 
     def _clean_properties(self, node: InferredSchema) -> None:

unit_tests/utils/test_schema_inferrer.py

@@ -228,6 +228,7 @@
                                         "nested_key_2": "United Kingdom",
                                     },
                                 },
+                                {"title": "Nested_3", "type": "string", "value": "XL"},
                             ],
                         }
                     },
@@ -247,6 +248,7 @@
                                         "type": {"type": ["string", "null"]},
                                         "value": {
                                             "anyOf": [
+                                                {"type": "string"},
                                                 {"type": "array", "items": {"type": "string"}},
                                                 {
                                                     "type": "object",