from genesis.parsers.paragraph_splitter import split_paragraphs


def test_empty_matrix():
    assert split_paragraphs([]) == []


def test_single_paragraph_no_empty_rows():
    m = [["a", "b"], ["c", "d"]]
    assert split_paragraphs(m) == [(0, 1)]


def test_split_on_middle_empty_row():
    m = [["a"], [], ["b"], ["c"], []]
    assert split_paragraphs(m) == [(0, 0), (2, 3)]


def test_trailing_empty_rows_no_extra_paragraph():
    m = [["a"], [], [], []]
    assert split_paragraphs(m) == [(0, 0)]


def test_leading_empty_rows_start_at_first_nonempty():
    m = [[], ["a"], [], ["b"]]
    assert split_paragraphs(m) == [(1, 1), (3, 3)]