sub do_tests {
    use Test::More;
    use Data::Dump 'pp';
    my @test_cases = (
        [   0, [] ],
        [   1, [1] ],
        [   2, [1, 2] ],
        [   3, [1, 3] ],
        [   4, [1, 2, 2] ],
        [ -72, [-1, 1, 2, 2, 2, 3, 3] ],
    );

    for my $case (@test_cases) {
        my @f = factors($case->[0]);
        # Uncomment for debugging
        #print "$case->[0], exp: (", join(",",@{$case->[1]}), "), got(", join(",",@f),")\n";
        is_deeply([@f], $case->[1]);
    }
    done_testing();
}