feat: assert_min_num_of_args

dol/trans.py

@@ -3232,6 +3232,20 @@ def ingress(self, x):
     def egress(self, y):
         return self.egress_map[y]
 
+def assert_min_num_of_args(func: Callable, num_of_args: int):
+    """Assert that a function can be a store method.
+    That is, it should have a signature that takes the store as the first argument
+    """
+    try:
+        assert len(sig = Sig(func).parameters) >= assert_min_num_of_args, (
+            f"Function {func} doesn't have at least {num_of_args} arguments"
+        )
+    except Exception as e:
+        warn(
+            f"Encountered error checking if {func} can be a store method. "
+            "Will return True, to not disrupt process, but you may want to check on "
+            f"this : {e}"
+        )
 
 @store_decorator
 def add_missing_key_handling(store=None, *, missing_key_callback: Callable):
@@ -3261,7 +3275,9 @@ def add_missing_key_handling(store=None, *, missing_key_callback: Callable):
     >>> v = s['a/']
     >>> assert dict(v) == {'a/b': 1, 'a/c': 2}
     """
-
+
+    assert_min_num_of_args(missing_key_callback, 2)
+
     @wraps(store, updated=())
     class StoreWithMissingKeyCallaback(store):
         pass