From 24c44efc9f8cd981aed47f275b350e17e8ab2eed Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Sebasti=C3=A1n=20Ram=C3=ADrez?= Date: Thu, 20 Mar 2025 13:41:41 +0100 Subject: [PATCH] =?UTF-8?q?=F0=9F=90=9B=20Fix=20convert=5Funderscores=3DFa?= =?UTF-8?q?lse=20for=20Header=20Pydantic=20models?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- fastapi/dependencies/utils.py | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fastapi/dependencies/utils.py b/fastapi/dependencies/utils.py index d205d17fa..84dfa4d03 100644 --- a/fastapi/dependencies/utils.py +++ b/fastapi/dependencies/utils.py @@ -750,9 +750,15 @@ def request_params_to_args( first_field = fields[0] fields_to_extract = fields single_not_embedded_field = False + default_convert_underscores = True if len(fields) == 1 and lenient_issubclass(first_field.type_, BaseModel): fields_to_extract = get_cached_model_fields(first_field.type_) single_not_embedded_field = True + # If headers are in a Pydantic model, the way to disable convert_underscores + # would be with Header(convert_underscores=False) at the Pydantic model level + default_convert_underscores = getattr( + first_field.field_info, "convert_underscores", True + ) params_to_process: Dict[str, Any] = {} @@ -763,7 +769,9 @@ def request_params_to_args( if isinstance(received_params, Headers): # Handle fields extracted from a Pydantic Model for a header, each field # doesn't have a FieldInfo of type Header with the default convert_underscores=True - convert_underscores = getattr(field.field_info, "convert_underscores", True) + convert_underscores = getattr( + field.field_info, "convert_underscores", default_convert_underscores + ) if convert_underscores: alias = ( field.alias