Add tests for core module

• Tester le core module

added Improvment label

assigned to @tguillas

added Doing label

created merge request !13 (merged) to address this issue

mentioned in merge request !13 (merged)

mentioned in commit 6faff9da

closed with merge request !13 (merged)

mentioned in merge request !14 (merged)

mentioned in commit b9120e91

mentioned in merge request !15 (merged)

mentioned in commit 69d8245c

removed Doing label