Test broken after upgrade to latest moto version (1.3.15 and 1.3.16)

Question

Updating moto from version 1.3.14 to 1.3.15/1.3.16 breaks tests throwing an Exception.

It throws an error even using the annotation alone.

I using this requiriments.txt file:

moto==1.3.16

This test example is working with moto 1.3.14 but it is not with newer versions:

from moto import mock_s3
import unittest

@mock_s3
class TestStringMethods(unittest.TestCase):

    def test_upper(self):
        self.assertEqual('foo'.upper(), 'FOO')


if __name__ == '__main__':
    unittest.main()

This is the error when executing python3 -m unittest mytest.py:

(venv) ~/p/mocotest $ python3 -m unittest mytest.py
ETraceback (most recent call last):
  File "/usr/lib/python3.8/runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/lib/python3.8/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/usr/lib/python3.8/unittest/__main__.py", line 18, in <module>
    main(module=None)
  File "/usr/lib/python3.8/unittest/main.py", line 101, in __init__
    self.runTests()
  File "/usr/lib/python3.8/unittest/main.py", line 271, in runTests
    self.result = testRunner.run(self.test)
  File "/usr/lib/python3.8/unittest/runner.py", line 176, in run
    test(result)
  File "/usr/lib/python3.8/unittest/suite.py", line 84, in __call__
    return self.run(*args, **kwds)
  File "/usr/lib/python3.8/unittest/suite.py", line 122, in run
    test(result)
  File "/usr/lib/python3.8/unittest/suite.py", line 84, in __call__
    return self.run(*args, **kwds)
  File "/usr/lib/python3.8/unittest/suite.py", line 122, in run
    test(result)
  File "/usr/lib/python3.8/unittest/suite.py", line 84, in __call__
    return self.run(*args, **kwds)
  File "/usr/lib/python3.8/unittest/suite.py", line 122, in run
    test(result)
  File "/usr/lib/python3.8/unittest/case.py", line 736, in __call__
    return self.run(*args, **kwds)
  File "/home/cerveraa/projects/mocotest/venv/lib/python3.8/site-packages/moto/core/models.py", line 102, in wrapper
    self.stop()
  File "/home/cerveraa/projects/mocotest/venv/lib/python3.8/site-packages/moto/core/models.py", line 86, in stop
    self.default_session_mock.stop()
  File "/home/cerveraa/projects/mocotest/venv/lib/python3.8/site-packages/mock/mock.py", line 1563, in stop
    return self.__exit__(None, None, None)
  File "/home/cerveraa/projects/mocotest/venv/lib/python3.8/site-packages/mock/mock.py", line 1529, in __exit__
    if self.is_local and self.temp_original is not DEFAULT:
AttributeError: '_patch' object has no attribute 'is_local'

Versions:

• Python 3.8.5
• pip 20.0.2

Any suggestion?

Note 1: For testing, I'm using a clean new venv environment and the only library installed is moto.

Note 2: Using 1.3.14 works fine, but with a warning when installing dependencies:

ERROR: python-jose 3.2.0 has requirement ecdsa<0.15, but you'll have ecdsa 0.16.1 which is incompatible

Answer 1

• It's the compatibility problem between moto and mock libraries
• Using moto version moto==1.3.16 and mock version mock==4.0.2 solved the issue for me.

Answer 2

Same problem. patch feature from moto models affects mock funcionality.

(workaround): comment lines affected

def __exit__(self, *exc_info):
        """Undo the patch."""
        #if self.is_local and self.temp_original is not DEFAULT:
        #    setattr(self.target, self.attribute, self.temp_original)
        #else:
        #    delattr(self.target, self.attribute)
        #    if not self.create and (not hasattr(self.target, self.attribute) or
        #                self.attribute in ('__doc__', '__module__',
        #                                   '__defaults__', '__annotations__',
        #                                   '__kwdefaults__')):
        #        # needed for proxy objects like django settings
        #        setattr(self.target, self.attribute, self.temp_original)

        #del self.temp_original
        #del self.is_local
        #del self.target
        exit_stack = self._exit_stack
        #del self._exit_stack
        return exit_stack.__exit__(*exc_info)