"""Tests for util module."""

import pytest

from accounting import util


@pytest.mark.parametrize(
    'n, source, expected_result', [
        (4, range(0, 10), [[0, 1, 2, 3], [4, 5, 6, 7], [8, 9]]),
        (10, range(0, 10), [[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]]),
        (1, range(0, 10), [[0], [1], [2], [3], [4], [5], [6], [7], [8], [9]]),
        (10, range(0, 10), [[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]]),
    ]
)
def test_grouper(n, source, expected_result):
    """Test grouper function iterates the correct sequence."""
    result = [list(chunk) for chunk in util.grouper(n, source)]
    assert result == expected_result