Add reinstall command

[agatti]

Right now there's no real automated way to update casks except than removing and reinstalling items. This patch acts as a stopgap measure to make manual updates slightly less painful, to be possibly deprecated once automated updates are in place.

This can probably be replaced by a shell script/shell alias, but maybe it might still be useful if integrated in the brew-cask script. The patch didn't touch the changelog, as I'm not sure what's the policy for that.

[rolandwalker]

Hi! Thanks!

No, we don't modify the changelog until release time. Yes, we definitely need to work on removing/upgrading.

How is this implementation different from brew cask install --force ?

[agatti]

Hrmmmm, I didn't consider install --force as an equivalent for this. Indeed it does the same thing so I suppose this can be closed (although reinstall could be aliased to install --force, maybe?) - sorry for the unnecessary review. I do have a couple of ideas on how to handle upgrading in some cases for brew-cask but my Ruby skills are nowhere near useful to submit a proper pull request for that :|

[rolandwalker]

Your input is appreciated here! Nobody is grading you for Ruby skills.

install --force is a lousy interface for upgrades. The only thing I can say in its favor is that at least the user will be informed that a proper upgrade is not really what is happening.

Perhaps we should start with improving the docs? The existing functionality (such as it is) must not have been explained well enough, given that you worked on this implementation.

[NorthIsUp]

@rolandwalker what about an alias from upgrade to install --force, would that be sufficient?

[rolandwalker]

Sadly, no. If you look at mjolnirapp/mjolnir#212, you will see that Hydra (a very cool app, btw) pulled their Cask because of bugs caused by old copies left lying around after brew cask install --force.

To reliably remove old copies, we need "bookkeeping" AKA #3066. Before merging #3066 we are working to stabilize the Cask Language per #4688. You will see that we are quite far along in #4688, although we could use some help on the items in #4678.