Correctly handle self in posargs2kwargs

Author: domdfcoding

domdf_python_tools/utils.py

@@ -263,8 +263,7 @@ def posargs2kwargs(
 	self_arg = None
 
 	if isinstance(posarg_names, MethodType):
-		posarg_names = inspect.getfullargspec(posarg_names).args
-		self_arg = posarg_names[0]
+		self_arg, *posarg_names = inspect.getfullargspec(posarg_names).args
 	elif callable(posarg_names):
 		posarg_names = inspect.getfullargspec(posarg_names).args
 

tests/test_utils.py

@@ -286,7 +286,7 @@ def demo_function(arg1, arg2, arg3):
 							"buffering": -1,
 							"encoding": "UTF-8",
 							}),
-				((cwd, "wb", -1, "UTF-8"),
+				(("wb", -1, "UTF-8"),
 					pathlib.Path().open,
 					None, {
 							"mode": "wb",