I'm just wondering as i have a 6 speed 105 rear derailleur (rd 1050) and a 7 speed wheelset. If I grab a set of 7 speed indexed shifters will the derailleur shift as 7 speed indexed or is the only way to run this as 7 speed would be with friction shifters?

edit: idk if this should HO here or in the mechanics section, if it's more appropriate there please move the threads mods. Thanks!