Shelving – What is it – and more importantly, can it help me?
- by Chris Skardon
Since we shifted to TFS we’ve had the ability to perform what is known as ‘shelving’. Shelving (whilst not a wholly new topic in the world of SCC) is new to us, and didn’t exist in our previous SCC solution – SVN. Soo… what is it? What? Shelving is a way to check-in but not check-in your code. By shelving you submit a copy of your ‘pending changes’ to the SCC server, (which maintains a list of the shelvesets) and once that is done you can either continue working, or undo your changes, safe in the knowledge that a backup copy exists on the server. You can unshelve your code at any time and get back to the state you were when you shelved. Yer, that is great but why not just check it in?? Shelvesets don’t have to build. The shelveset you put in there could be entirely broken, or it might solve every bug in the system – shelves aren’t continuously integrated so you can shelve anything. Hmmmm… What else? Shelving allows us to do some pretty cool stuff that beforehand was quite frankly a pain. For instance – Gated Check-ins are implemented via the shelving mechanism, when code is checked-in, what you’re actually doing is shelving it, the Build Controller will build the shelveset with the original code and if it succeeds, the code will be committed, if it fails – well – it’s only you that has to fix the code :) Other nice features are things like the ability to share code you are working on… For example, if I was having trouble with a particular piece of code, I could shelve it, and then you (yes you) could then get that shelveset and check out the problem for yourself, and if you fix it?? Well – you could check-it in! Nice, but day-to-day shizzle? Let’s say you’ve been working on your project and your project manager comes over to you and says: “Hey, errr, bad times, there is an urgent bug we need you to fix, it needs to go out now!” (also for this to play out – we’ll need to assume you’re currently working in the 'release’ branch for another bug fix (maybe))… You could undo all your current changes (obviously you’ll probably backup your code using zip or something I imagine) fix the bug, then re-copy your backup over the top, or you could shelve and unshelve. Perhaps some other uses will awaken the shelver in you… :) Before each checkin – if you shelve, you no longer need to worry (if indeed you do) about resolving conflicts and mysteriously losing your code… Going home at night? Not checking in straight away? Why not shelve, this way – should the worst come to the worst and your local pc gives up, you can just get the shelveset onto another machine and be up and running in literally seconds minutes…
