Modify get_directory_description to return a flat cell
(cherry picked from commit b840af9fa584a5468e5208bf41d0db8ec737aa74)
Add unitary tests to testsuite
(cherry picked from commit 5f3d56c31aed18a7b6f22625b373233946561fd5)
Update tests/.gitignore
(cherry picked from commit c7cb38e687f968da0361eb10164b894417bf67af)