Base mod:https://mods.factorio.com/mod/long-chest

Modify the chest so that it automatically merges into a new, longer chest when placed adjacent to another chest. The lengths of the chestes should be in increments of 5, 5, 10, 15, and so on, up to a maximum length of 200.

Reference modification:https://mods.factorio.com/mod/LB-Modular-Chests

Thank Plexpt.