Fix union handling of Annotated types

Author: yugokato

src/openapi_test_client/libraries/api/api_functions/utils/endpoint_function.py

@@ -171,24 +171,38 @@ def generate_rest_func_params(
         else:
             if field_obj := dataclass_fields.get(param_name):
                 # Check Annotated metadata
-                if annotated_type := param_type_util.get_annotated_type(field_obj.type):
-                    if isinstance(annotated_type, list | tuple):
-                        # Select the first annotaed type where the type of the given param value matches
-                        annotated_type = [
-                            x
-                            for x in annotated_type
-                            if param_type_util.is_type_of(get_args(annotated_type)[0], type(param_value))
-                        ] or annotated_type[0]
-
-                    # Process alias name and query parameter
-                    metadata = annotated_type.__metadata__
-                    if alias_param := [x for x in metadata if isinstance(x, Alias)]:
-                        assert len(alias_param) == 1
-                        # Resolve the actual param name
-                        param_name = alias_param[0].value
-
-                    if "query" in metadata:
-                        query[param_name] = param_value
+                if field_obj := dataclass_fields.get(param_name):
+                    # Check Annotated metadata
+                    if annotated_type := param_type_util.get_annotated_type(field_obj.type):
+                        if isinstance(annotated_type, list | tuple):
+                            # This field has more than one Annotated[] as a union. We will try to find the right one for
+                            # this request where the type of the given param value matches. If none of them match,
+                            # select the first one and log warning message
+                            try:
+                                annotated_type = next(
+                                    x
+                                    for x in annotated_type
+                                    if param_type_util.is_type_of(get_args(x)[0], type(param_value))
+                                )
+                            except StopIteration:
+                                annotated_type = annotated_type[0]
+                                logger.warning(
+                                    f"The field type of '{endpoint.model.__name__}.{param_name}' has more than 1 "
+                                    f"Annotated[] types, but the type of the provided value does not match with any of "
+                                    f"them. The first annotated type will be used for this API call.\n"
+                                    f"- Defined field type: {field_obj.type}\n"
+                                    f"- Provided value type: {type(param_value)}"
+                                )
+
+                        # Process alias name and query parameter
+                        metadata = annotated_type.__metadata__
+                        if alias_param := [x for x in metadata if isinstance(x, Alias)]:
+                            assert len(alias_param) == 1
+                            # Resolve the actual param name
+                            param_name = alias_param[0].value
+
+                        if "query" in metadata:
+                            query[param_name] = param_value
 
             if param_name not in query.keys():
                 if use_query_string: