Allow zero mutations/querys in graph

Author: marcelldls

src/fastcs/backends/graphQL/graphQL.py

@@ -139,17 +139,19 @@ def get_child(self, name: str) -> "FieldsTree":
                 return child
         raise NodeNotFoundError
 
-    def create_type(self, strawberry_type: str) -> type:
+    def create_type(self, strawberry_type: str) -> type | None:
         for child in self.children:
-            child_field = _wrap_as_field(
-                child.name,
-                child.create_type(strawberry_type),
-            )
-            self.fields_dict[strawberry_type].append(child_field)
+            if new_type := child.create_type(strawberry_type):
+                child_field = _wrap_as_field(
+                    child.name,
+                    new_type,
+                )
+                self.fields_dict[strawberry_type].append(child_field)
 
-        return create_type(
-            f"{self.name}{strawberry_type}", self.fields_dict[strawberry_type]
-        )
+        if self.fields_dict[strawberry_type]:
+            return create_type(
+                f"{self.name}{strawberry_type}", self.fields_dict[strawberry_type]
+            )
 
 
 def _add_dev_attributes(