def clean_system(request) -> None:
    """Fixture. Simulates a clean system with no configured or cloned cookiecutters.

    It runs code which can be regarded as setup code as known from a unittest
    TestCase. Additionally it defines a local function referring to values
    which have been stored to local variables in the setup such as the location
    of the cookiecutters on disk. This function is registered as a teardown
    hook with `request.addfinalizer` at the very end of the fixture. Pytest
    runs the named hook as soon as the fixture is out of scope, when the test
    finished to put it another way.

    During setup:

    * Back up the `~/.cookiecutterrc` config file to `~/.cookiecutterrc.backup`
    * Back up the `~/.cookiecutters/` dir to `~/.cookiecutters.backup/`
    * Back up the `~/.cookiecutter_replay/` dir to
      `~/.cookiecutter_replay.backup/`
    * Starts off a test case with no pre-existing `~/.cookiecutterrc` or
      `~/.cookiecutters/` or `~/.cookiecutter_replay/`

    During teardown:

    * Delete `~/.cookiecutters/` only if a backup is present at
      `~/.cookiecutters.backup/`
    * Delete `~/.cookiecutter_replay/` only if a backup is present at
      `~/.cookiecutter_replay.backup/`
    * Restore the `~/.cookiecutterrc` config file from
      `~/.cookiecutterrc.backup`
    * Restore the `~/.cookiecutters/` dir from `~/.cookiecutters.backup/`
    * Restore the `~/.cookiecutter_replay/` dir from
      `~/.cookiecutter_replay.backup/`

    """
    # If ~/.cookiecutterrc is pre-existing, move it to a temp location
    user_config_path = os.path.expanduser('~/.cookiecutterrc')
    user_config_path_backup = os.path.expanduser('~/.cookiecutterrc.backup')
    if os.path.exists(user_config_path):
        user_config_found = True
        shutil.copy(user_config_path, user_config_path_backup)
        os.remove(user_config_path)
    else:
        user_config_found = False

    # If the default cookiecutters_dir is pre-existing, move it to a
    # temp location
    cookiecutters_dir = os.path.expanduser('~/.cookiecutters')
    cookiecutters_dir_backup = os.path.expanduser('~/.cookiecutters.backup')
    cookiecutters_dir_found = backup_dir(cookiecutters_dir, cookiecutters_dir_backup)

    # If the default cookiecutter_replay_dir is pre-existing, move it to a
    # temp location
    cookiecutter_replay_dir = os.path.expanduser('~/.cookiecutter_replay')
    cookiecutter_replay_dir_backup = os.path.expanduser('~/.cookiecutter_replay.backup')
    cookiecutter_replay_dir_found = backup_dir(
        cookiecutter_replay_dir, cookiecutter_replay_dir_backup
    )

    def restore_backup() -> None:
        # If it existed, restore ~/.cookiecutterrc
        # We never write to ~/.cookiecutterrc, so this logic is simpler.
        if user_config_found and os.path.exists(user_config_path_backup):
            shutil.copy(user_config_path_backup, user_config_path)
            os.remove(user_config_path_backup)

        # Carefully delete the created ~/.cookiecutters dir only in certain
        # conditions.
        restore_backup_dir(
            cookiecutters_dir, cookiecutters_dir_backup, cookiecutters_dir_found
        )

        # Carefully delete the created ~/.cookiecutter_replay dir only in
        # certain conditions.
        restore_backup_dir(
            cookiecutter_replay_dir,
            cookiecutter_replay_dir_backup,
            cookiecutter_replay_dir_found,
        )

    request.addfinalizer(restore_backup)
Fixture. Simulates a clean system with no configured or cloned cookiecutters.

    It runs code which can be regarded as setup code as known from a unittest
    TestCase. Additionally it defines a local function referring to values
    which have been stored to local variables in the setup such as the location
    of the cookiecutters on disk. This function is registered as a teardown
    hook with `request.addfinalizer` at the very end of the fixture. Pytest
    runs the named hook as soon as the fixture is out of scope, when the test
    finished to put it another way.

    During setup:

    * Back up the `~/.cookiecutterrc` config file to `~/.cookiecutterrc.backup`
    * Back up the `~/.cookiecutters/` dir to `~/.cookiecutters.backup/`
    * Back up the `~/.cookiecutter_replay/` dir to
      `~/.cookiecutter_replay.backup/`
    * Starts off a test case with no pre-existing `~/.cookiecutterrc` or
      `~/.cookiecutters/` or `~/.cookiecutter_replay/`

    During teardown:

    * Delete `~/.cookiecutters/` only if a backup is present at
      `~/.cookiecutters.backup/`
    * Delete `~/.cookiecutter_replay/` only if a backup is present at
      `~/.cookiecutter_replay.backup/`
    * Restore the `~/.cookiecutterrc` config file from
      `~/.cookiecutterrc.backup`
    * Restore the `~/.cookiecutters/` dir from `~/.cookiecutters.backup/`
    * Restore the `~/.cookiecutter_replay/` dir from
      `~/.cookiecutter_replay.backup/`

    
tests/conftest.py