Merge pull request #935 from j0k2r/dev

Fix loader functon for async methods

src/webargs/core.py

@@ -2,6 +2,7 @@
 
 import asyncio
 import functools
+import inspect
 import json
 import logging
 import typing
@@ -237,10 +238,12 @@ async def _async_load_location_data(
         # an async variant of the _load_location_data method
         # the loader function itself may or may not be async
         loader_func = self._get_loader(location)
-        if asyncio.iscoroutinefunction(loader_func):
-            data = await loader_func(req, schema)
-        else:
-            data = loader_func(req, schema)
+
+        data = loader_func(req, schema)
+
+        if inspect.isawaitable(data):
+            return await data
+
         return data
 
     def _on_validation_error(