Deprecated assertEquals (and similar methods) don't work in marbles

[leifwalsh]

• marbles.core version: 0.9.5
• marbles.mixins version: 0.9.5
• Python version: 3.6.5
• Operating System: Linux

Description

Tried to run a unittest test that uses the deprecated name assertEquals instead of assertEqual.

What I Did

import marbles.core

class MyTestCase(marbles.core.TestCase):

    def test_assertEqual_success(self):
        x = 1
        y = 1
        self.assertEqual(x, y)

    def test_assertEqual_failure(self):
        x = 1
        y = 2
        self.assertEqual(x, y)

    def test_assertEquals_success(self):
        x = 1
        y = 1
        self.assertEquals(x, y)

    def test_assertEquals_failure(self):
        x = 1
        y = 2
        self.assertEquals(x, y)

The assertEquals tests fail with the following stack:

======================================================================
ERROR: test_deprecated_assertEquals_failure (tests.test_marbles.InterfaceTestCase) (use_annotated_test_case=False)
Does the deprecated assertEquals method work on failure?
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/leif/git/marbles/marbles/core/tests/test_marbles.py", line 373, in test_deprecated_assertEquals_failure
    self.case.test_deprecated_assertEquals_failure()
  File "/home/leif/git/marbles/marbles/core/tests/test_marbles.py", line 93, in test_deprecated_assertEquals_failure
    self.assertEquals(x, y)
  File "/home/leif/git/marbles/marbles/core/marbles/core/marbles.py", line 538, in wrapper
    return attr(*args, msg=annotation, **kwargs)
  File "/usr/lib64/python3.6/unittest/case.py", line 1323, in deprecated_func
    return original_func(*args, **kwargs)
TypeError: assertEqual() missing 1 required positional argument: 'second'

======================================================================
ERROR: test_deprecated_assertEquals_success (tests.test_marbles.InterfaceTestCase) (use_annotated_test_case=False)
Does the deprecated assertEquals method still work?
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/leif/git/marbles/marbles/core/tests/test_marbles.py", line 364, in test_deprecated_assertEquals_success
    self.case.test_deprecated_assertEquals_success()
  File "/home/leif/git/marbles/marbles/core/tests/test_marbles.py", line 88, in test_deprecated_assertEquals_success
    self.assertEquals(x, y)
  File "/home/leif/git/marbles/marbles/core/marbles/core/marbles.py", line 538, in wrapper
    return attr(*args, msg=annotation, **kwargs)
  File "/usr/lib64/python3.6/unittest/case.py", line 1323, in deprecated_func
    return original_func(*args, **kwargs)
TypeError: assertEqual() missing 1 required positional argument: 'second'

----------------------------------------------------------------------

Expected behavior

I expected assertEqual and assertEquals to behave the same. Instead, assertEqual does the expected thing, while assertEquals fails with a TypeError

[leifwalsh]

I ran this in pdb and found the following:

> /usr/lib64/python3.6/unittest/case.py(1322)deprecated_func()
-> return original_func(*args, **kwargs)
(Pdb) p args
(<tests.test_marbles.ExampleTestCase testMethod=runTest>, 1)
(Pdb) p kwargs
{'msg': {'msg': 2, 'note': None}}

It seems that we're incorrectly assuming the last argument here is the msg and packaging that up, rather than forwarding it along.

[leifwalsh]

This is because we inspect the method signature to find the msg argument (here) to figure out which one to pull out, but since this deprecated method's signature is actually (*args, **kwargs), we default to pulling the last argument out as msg, when in actuality we should pass through at this level and catch the msg argument when it calls through to assertEqual.

Not sure exactly what to do here, perhaps we should detect when the assertion method is one of these passthroughs

[tirkarthi]

Note : In Python 3.11 the deprecated aliases have been removed in python/cpython#28268