…iprep into alistair/bids_format

…iprep into alistair/bids_format

@pytest.fixture
def mock_file_system():
    with mock.patch('os.listdir') as mock_listdir, \
         mock.patch('os.path.isdir') as mock_isdir, \
         mock.patch('os.path.exists') as mock_exists, \
         mock.patch('os.path.isfile') as mock_isfile:
        # Mock the directory structure
        def listdir_side_effect(path):
            if path == 'mock_bids_dir_path':
                return ['sub-1']
            elif path == 'mock_bids_dir_path/sub-1':
                return ['ses-1', 'ses-2']
            elif path == 'mock_bids_dir_path/sub-1/ses-1':
                return []
            elif path == 'mock_bids_dir_path/sub-1/ses-2':
                return ['audio-1.wav', 'otherfile.txt']
            return []

        def isdir_side_effect(path):
            return path in [
                'mock_bids_dir_path',
                'mock_bids_dir_path/sub-1',
                'mock_bids_dir_path/sub-1/ses-1',
                'mock_bids_dir_path/sub-1/ses-2'
            ]

        def exists_side_effect(path):
            return path in [
                'mock_bids_dir_path',
                'mock_bids_dir_path/sub-1',
                'mock_bids_dir_path/sub-1/ses-1',
                'mock_bids_dir_path/sub-1/ses-2',
                'mock_bids_dir_path/sub-1/ses-2/audio-1.wav',
                'mock_bids_dir_path/sub-1/ses-2/otherfile.txt'
            ]

        def isfile_side_effect(path):
            return path in [
                'mock_bids_dir_path/sub-1/ses-2/audio-1.wav',
                'mock_bids_dir_path/sub-1/ses-2/otherfile.txt'
            ]

        mock_listdir.side_effect = listdir_side_effect
        mock_isdir.side_effect = isdir_side_effect
        mock_exists.side_effect = exists_side_effect
        mock_isfile.side_effect = isfile_side_effect
        yield