Warnings are good but not perfect. At the end of the day, you can’t help everyone with just warnings. You could make the UI bright flashing red, with a skull and crossbones, have it say “Never invoke this: it will delete all your data and kill your dog. Please type ‘I_WANT_CANCER’ to continue.” And users will do it. It can’t be helped. The only (admittedly hard) way is UNDO.
Undo. If it's possible, you want undo. If it's difficult, you still want undo. Only when you've satisfied yourself that it's outright impossible should you reluctantly design the UX with the "Are you sure?" prompt instead.
Also, if you must have I_WANT_CANCER type prompts, try to make them involve expressing what it is that the human is agreeing to, because sometimes it's only at that point the human realises their plan was very stupid. GitHub does that here (you have to type the name of the repo, to delete main_project you'll need to type main_project) but many things do not.
This is why I like Git's force-with-lease. When I try to forcibly overwrite the state, because I know Jim's push was wrong and must be undone, force-with-lease makes me express that, "--force-with-lease=jim-daft-change". And when in fact what I'm going to overwrite is Lisa's urgent bug fix, not Jim's erroneous change, the force-with-lease fails and to get it to apply this way I'd need to say "--force-with-lease=lisa-bug-fix" and that's one last opportunity to say "Wait, what? That's not what I want to do".
I think from UX perspective it is unbelievably more convenient as well. Plain popup warnings with "press Ok if you mean it" are bad enough, but quite recently the new even worse "type delete, if you want to delete, then press Ok" popup has been spreading about... If I want to delete over a couple of things I get incredibly irked.
- (not intrinsic) many interfaces only give you a few seconds to undo your action, which wouldn't help in this case
- (intrinsic) some events can be layered on top of your change, meaning that you have to either block the undo or reverse all the subsequent events too. This wouldn't be the case for this HTTPie incident, but does prevent UNDO functionality from being a silver bullet.
