bpo-36492: Deprecate passing some arguments as keyword arguments. (GH-12637)

Deprecated passing the following arguments as keyword arguments:

- "func" in functools.partialmethod(), weakref.finalize(),
  profile.Profile.runcall(), cProfile.Profile.runcall(),
  bdb.Bdb.runcall(), trace.Trace.runfunc() and
  curses.wrapper().
- "function" in unittest.addModuleCleanup() and
  unittest.TestCase.addCleanup().
- "fn" in the submit() method of concurrent.futures.ThreadPoolExecutor
  and concurrent.futures.ProcessPoolExecutor.
- "callback" in contextlib.ExitStack.callback(),
  contextlib.AsyncExitStack.callback() and
  contextlib.AsyncExitStack.push_async_callback().
- "c" and "typeid" in the create() method of multiprocessing.managers.Server
  and multiprocessing.managers.SharedMemoryServer.
- "obj" in weakref.finalize().

Also allowed to pass arbitrary keyword arguments (even "self" and "func")
if the above arguments are passed as positional argument.

1 files changed, 29 insertions, 0 deletions

diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index 1fac08d..50a46f8 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -1839,6 +1839,35 @@ class FinalizeTestCase(unittest.TestCase):
         self.assertEqual(f.alive, False)
         self.assertEqual(res, [199])
 
+    def test_arg_errors(self):
+        def fin(*args, **kwargs):
+            res.append((args, kwargs))
+
+        a = self.A()
+
+        res = []
+        f = weakref.finalize(a, fin, 1, 2, func=3, obj=4)
+        self.assertEqual(f.peek(), (a, fin, (1, 2), {'func': 3, 'obj': 4}))
+        f()
+        self.assertEqual(res, [((1, 2), {'func': 3, 'obj': 4})])
+
+        res = []
+        with self.assertWarns(DeprecationWarning):
+            f = weakref.finalize(a, func=fin, arg=1)
+        self.assertEqual(f.peek(), (a, fin, (), {'arg': 1}))
+        f()
+        self.assertEqual(res, [((), {'arg': 1})])
+
+        res = []
+        with self.assertWarns(DeprecationWarning):
+            f = weakref.finalize(obj=a, func=fin, arg=1)
+        self.assertEqual(f.peek(), (a, fin, (), {'arg': 1}))
+        f()
+        self.assertEqual(res, [((), {'arg': 1})])
+
+        self.assertRaises(TypeError, weakref.finalize, a)
+        self.assertRaises(TypeError, weakref.finalize)
+
     def test_order(self):
         a = self.A()
         res = []