Make InvalidNameError copyable and picklable

bibtexparser/middlewares/names.py

@@ -21,9 +21,17 @@ class InvalidNameError(ValueError):
     """Exception raised by :py:func:`parse_single_name_into_parts` when facing an invalid name."""
 
     def __init__(self, name: str, reason: str):
+        self.name = name
+        self.reason = reason
         message: str = f"Cannot split the following name `{name}` into parts: {reason}"
         super().__init__(message)
 
+    def __reduce__(self):
+        # Rebuild from name and reason so the exception stays copyable and
+        # picklable; the base ValueError stores only the formatted message in
+        # args, which does not match this two-argument __init__.
+        return (self.__class__, (self.name, self.reason))
+
 
 class _NameTransformerMiddleware(BlockMiddleware, abc.ABC):
     """Internal utility class - superclass for all name-transforming middlewares.

tests/middleware_tests/test_names.py

@@ -132,6 +132,24 @@ def test_name_splitting_strict_mode(name: str, reason: str):
         parse_single_name_into_parts(name, strict=True)
 
 
+def test_invalid_name_error_is_copyable():
+    # A MiddlewareErrorBlock stores the InvalidNameError, and later middlewares
+    # (for example SortBlocksByTypeAndKeyMiddleware) deepcopy the library, so
+    # the exception has to survive copy and pickle. It could not before: its
+    # two-argument __init__ did not match the single message stored in args.
+    import pickle
+
+    with pytest.raises(InvalidNameError) as exc_info:
+        parse_single_name_into_parts("AA, BB, CC, DD", strict=True)
+    error = exc_info.value
+
+    for clone in (deepcopy(error), pickle.loads(pickle.dumps(error))):
+        assert isinstance(clone, InvalidNameError)
+        assert str(clone) == str(error)
+        assert clone.name == error.name
+        assert clone.reason == error.reason
+
+
 def _dict_to_nameparts(as_dict):
     return NameParts(
         first=as_dict["first"],