I'm creating files with pathlib.Path.touch with the following method that I'd like to assert in a unittest using unitest.mock.patch decorator:

sessions.py

def generate_folders(paths: list):
    for p in paths:
        p.mkdir()
        Path(p / "output").mkdir()
        Path(p / "output" / "output_file").touch()
        Path(p / "session_file").touch()

test

    @patch("os.mkdir")
    @patch("pathlib.Path.touch")
    def test_folder_creation(self, touch_mock, mkdir_mock):
        tags = ["concepts", "models", "animations", "vfx", "sfx", "vo", "music"]
        paths = sessions.generate_paths(category="character", name="player", tags=tags)
        sessions.generate_folders(paths)
        for p in paths:
            mkdir_mock.assert_any_call(p, 511)
            mkdir_mock.assert_any_call(p / "output", 511)
            touch_mock.assert_any_call(Path(p / "output" / "output_file"), 511)
            touch_mock.assert_any_call(Path(p / "session_file"), 511)

I can assert folder creation by os.mkdir without any problem and I can also assert that pathlib.Path.touch has been called. However, asserting specific calls with assert_any_call() isn't possible. My test throws this output:

ssF...
======================================================================
FAIL: test_folder_creation (sessions.tests.sessions_tests.TestSessionsCreation.test_folder_creation)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\juank\AppData\Local\Programs\Python\Python313\Lib\unittest\mock.py", line 1424, in patched
    return func(*newargs, **newkeywargs)
  File "C:\Users\juank\dev\projects\python\gamedev_eco\sessions\tests\sessions_tests.py", line 51, in test_folder_creation
    touch_mock.assert_any_call(Path(p / "output" / "output_file"), 511)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\juank\AppData\Local\Programs\Python\Python313\Lib\unittest\mock.py", line 1048, in assert_any_call
    raise AssertionError(
        '%s call not found' % expected_string
    ) from cause
AssertionError: touch(WindowsPath('C:/Users/juank/dev/projects/python/gamedev_eco/sessions/character/player/concepts/output/output_file'), 511) call not found

----------------------------------------------------------------------
Ran 6 tests in 0.004s

FAILED (failures=1, skipped=2)

What confuses me about this test result is that in spite of checking that method input values are the same with pdb debugger, still the test fails. I also double-check that the decorators were working on os.mkdir and pathlib.Path.touch respectively.

On the other hand I tried patching touch with with but the test doesn't pass either. I can't tell if this issue is related to my code or to my test so I'd like to ask the community for hints please. What am I doing wrong? What am I missing?

I'm creating files with pathlib.Path.touch with the following method that I'd like to assert in a unittest using unitest.mock.patch decorator:

sessions.py

def generate_folders(paths: list):
    for p in paths:
        p.mkdir()
        Path(p / "output").mkdir()
        Path(p / "output" / "output_file").touch()
        Path(p / "session_file").touch()

test

    @patch("os.mkdir")
    @patch("pathlib.Path.touch")
    def test_folder_creation(self, touch_mock, mkdir_mock):
        tags = ["concepts", "models", "animations", "vfx", "sfx", "vo", "music"]
        paths = sessions.generate_paths(category="character", name="player", tags=tags)
        sessions.generate_folders(paths)
        for p in paths:
            mkdir_mock.assert_any_call(p, 511)
            mkdir_mock.assert_any_call(p / "output", 511)
            touch_mock.assert_any_call(Path(p / "output" / "output_file"), 511)
            touch_mock.assert_any_call(Path(p / "session_file"), 511)

I can assert folder creation by os.mkdir without any problem and I can also assert that pathlib.Path.touch has been called. However, asserting specific calls with assert_any_call() isn't possible. My test throws this output:

ssF...
======================================================================
FAIL: test_folder_creation (sessions.tests.sessions_tests.TestSessionsCreation.test_folder_creation)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\juank\AppData\Local\Programs\Python\Python313\Lib\unittest\mock.py", line 1424, in patched
    return func(*newargs, **newkeywargs)
  File "C:\Users\juank\dev\projects\python\gamedev_eco\sessions\tests\sessions_tests.py", line 51, in test_folder_creation
    touch_mock.assert_any_call(Path(p / "output" / "output_file"), 511)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\juank\AppData\Local\Programs\Python\Python313\Lib\unittest\mock.py", line 1048, in assert_any_call
    raise AssertionError(
        '%s call not found' % expected_string
    ) from cause
AssertionError: touch(WindowsPath('C:/Users/juank/dev/projects/python/gamedev_eco/sessions/character/player/concepts/output/output_file'), 511) call not found

----------------------------------------------------------------------
Ran 6 tests in 0.004s

FAILED (failures=1, skipped=2)

What confuses me about this test result is that in spite of checking that method input values are the same with pdb debugger, still the test fails. I also double-check that the decorators were working on os.mkdir and pathlib.Path.touch respectively.

On the other hand I tried patching touch with with but the test doesn't pass either. I can't tell if this issue is related to my code or to my test so I'd like to ask the community for hints please. What am I doing wrong? What am I missing?

• python
• mocking
• python-unittest

1 Answer 1

There's no way to call touch like pathlib.Path.touch("my_path") according to the documentation hence there's no way to assert it with touch_mock.assert_any_call(Path(p /"output"/"output_file")), it's just pointless. I'll only assert that the method has been called.