fix: refine the implementation of copy_behaviors (#3177)

src/awkward/_util.py

@@ -6,7 +6,6 @@
 import os
 import struct
 import sys
-import typing
 from collections.abc import Collection
 
 import numpy as np  # noqa: TID251
@@ -105,16 +104,16 @@ def unique_list(items: Collection[T]) -> list[T]:
     return result
 
 
-def copy_behaviors(existing_class: typing.Any, new_class: typing.Any, behavior: dict):
+def copy_behaviors(from_name: str, to_name: str, behavior: dict):
     output = {}
 
-    oldname = existing_class.__name__
-    newname = new_class.__name__
-
     for key, value in behavior.items():
-        if oldname in key:
-            if not isinstance(key, str) and "*" not in key:
-                new_tuple = tuple(newname if k == oldname else k for k in key)
+        if isinstance(key, str):
+            if key == from_name:
+                output[to_name] = value
+        else:
+            if from_name in key:
+                new_tuple = tuple(to_name if k == from_name else k for k in key)
                 output[new_tuple] = value
 
     return output

tests/test_2433_copy_behaviors.py

@@ -62,6 +62,12 @@ def __eq__(self, other):
     ak.behavior[numpy.add, "VectorTwoD", "VectorTwoD"] = lambda v1, v2: v1.add(v2)
     assert v + v == v_added
 
+    # instead of registering every operator again, just copy the behaviors of
+    # another class to this class
+    ak.behavior.update(
+        ak._util.copy_behaviors("VectorTwoD", "VectorTwoDAgain", ak.behavior)
+    )
+
     # second sub-class
     @ak.mixin_class(ak.behavior)
     class VectorTwoDAgain(VectorTwoD):
@@ -81,17 +87,14 @@ class VectorTwoDAgain(VectorTwoD):
         with_name="VectorTwoDAgain",
         behavior=ak.behavior,
     )
-    # add method works but the binary operator does not
     assert v.add(v) == v_added
-    with pytest.raises(TypeError):
-        v + v
+    assert v + v == v_added
 
     # instead of registering every operator again, just copy the behaviors of
     # another class to this class
     ak.behavior.update(
-        ak._util.copy_behaviors(VectorTwoD, VectorTwoDAgain, ak.behavior)
+        ak._util.copy_behaviors("VectorTwoDAgain", "VectorTwoDAgainAgain", ak.behavior)
     )
-    assert v + v == v_added
 
     # third sub-class
     @ak.mixin_class(ak.behavior)
@@ -112,14 +115,5 @@ class VectorTwoDAgainAgain(VectorTwoDAgain):
         with_name="VectorTwoDAgainAgain",
         behavior=ak.behavior,
     )
-    # add method works but the binary operator does not
     assert v.add(v) == v_added
-    with pytest.raises(TypeError):
-        v + v
-
-    # instead of registering every operator again, just copy the behaviors of
-    # another class to this class
-    ak.behavior.update(
-        ak._util.copy_behaviors(VectorTwoDAgain, VectorTwoDAgainAgain, ak.behavior)
-    )
     assert v + v == v_added