While reading Chuck's excellent post on the value of both knowing your problem domain before tackling your problem and checking in often, I found myself nodding profusely. I love it... he states:

Write tests first! Do it! DO IT NOW.

I'd like to add: NOW CHECK IN!!

I wish I could...often my problem is *when* to check in. I know I have to do it often, but when? After I finish a task? What if that is a few days away? What is a reasonable amount of time?

When I say task I am referring to a TFS work item. Since we are a scrum shop now it is actually a sprint backlog item. I have TDD at my side, and we have CI builds at work. Why not check in after every passing test cycle?

To be honest, checking in after every passing test feels like I'm wasting more time doing the check in dance, than I am saving time. Having said that, it appears that this is a widely accepted approach. 

Martin Fowler suggests otherwise. It appears he is task oriented when it comes to checking in:

Now I take my working copy and do whatever I need to do to complete my task. This will consist of both altering the production code, and also adding or changing automated tests.

...

With a good build, I can then think about committing my changes into the repository.

I think it feels more natural that way. Its like a 'reward' for finishing a task. The feedback loop advantage of TDD isn't hindered by the longer feedback time of a CI build so much.

However, I'm often left with sprint backlog items whose scope might mean that I'm programming for days on end. This is the root of check in evil for me. If a work item is so broad that it will take days to complete, then the impetus to check in is diminished such that I can get so wrapped up in the detail of the problem that I will forget to check in.

And that's my fault.

I'd love to blame it on the process but I can't. Sure the analysis of the product backlog item could have been more thorough, but we don't want to get too far into implementation details at that point or else we waste the whole teams time.

I should have the sense upon undertaking a task that has been written up as "Import old Foo data for Foo version 2", to split it up in to its discreet units of work. There are SQL tables to write create scripts for. There is a transformation layer to design and implement. There is deployment to think about. Acceptance testing. So on and so forth.

It is *my job* to define the goals on the road to task completion.

So I come full circle and refer back to Chuck's post and the idea that we should think about what we are going to do before we go and do it. Coding from hip make pain for coder </grunt>

Accept a task and analyse the problem domain.

Divide it up into check in sized work items.

Eat. Repeat.