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RELEASE.md

@@ -1,4 +1,4 @@
 Release type: patch
 
-Fix a bug "a custom resolver with permission_classes doesn't accept @sync_to_async decorator"
-The root cause was inspect.iscoroutinefunction() function returns True only for functions defined with "async def".
+Fix a bug ''a custom resolver with permission_classes doesn't accept @sync_to_async decorator"
+The root cause was inspect.iscoroutinefunction() function returns True only for functions defined with "async def" in python < 3.12

strawberry/types/fields/resolver.py

@@ -172,6 +172,12 @@ def is_reserved_type(self, other: builtins.type) -> bool:
 
 T = TypeVar("T")
 
+#  asyncio.iscoroutinefunction was deprecated in python >= 3.12
+if hasattr(inspect, "markcoroutinefunction"):
+    iscoroutinefunction = inspect.iscoroutinefunction
+else:
+    iscoroutinefunction = asyncio.iscoroutinefunction
+
 
 class StrawberryResolver(Generic[T]):
     RESERVED_PARAMSPEC: Tuple[ReservedParameterSpecification, ...] = (
@@ -345,10 +351,6 @@ def is_graphql_generic(self) -> bool:
 
     @cached_property
     def is_async(self) -> bool:
-        if hasattr(inspect, "markcoroutinefunction"):
-            iscoroutinefunction = inspect.iscoroutinefunction
-        else:
-            iscoroutinefunction = asyncio.iscoroutinefunction
         return iscoroutinefunction(self._unbound_wrapped_func) or isasyncgenfunction(
             self._unbound_wrapped_func
         )