fix: explicit error message when no content-type is provided

Signed-off-by: Raphael Glon <[email protected]>

Author: oOraph

src/huggingface_inference_toolkit/serialization/base.py

@@ -37,6 +37,9 @@
 class ContentType:
     @staticmethod
     def get_deserializer(content_type: str, task: str):
+        if not content_type:
+            message = f"No content type provided and no default one configured."
+            raise Exception(message)
         if content_type.lower().startswith("application/octet-stream"):
             if "audio" in task or "speech" in task:
                 return Audioer

src/huggingface_inference_toolkit/webservice_starlette.py

@@ -106,7 +106,7 @@ async def predict(request):
     try:
         task = request.path_params.get("task", HF_TASK)
         # extracts content from request
-        content_type = request.headers.get("content-Type", os.environ.get("DEFAULT_CONTENT_TYPE")).lower()
+        content_type = request.headers.get("content-Type", os.environ.get("DEFAULT_CONTENT_TYPE", "")).lower()
         # try to deserialize payload
         deserialized_body = ContentType.get_deserializer(content_type, task).deserialize(
             await request.body()