[mikekchar]

Intermediate results are fine as long as the tests are passing. If you push, then your teammates will see what you are doing and one of them can give you advice if they think you are going in a disadvantageous direction.

If you hold the code out for a whole day, there is no way for anyone else to know what you are doing (unless you interrupt them to tell them, or they somehow know to ask you). On a well functioning TBD team with true CI, everybody knows what everybody else is doing because they are constantly looking at diffs when they pull trunk.

But yes, it is extreme ;-) It's one of the 12 XP practices (continuous integration). Interestingly, the original idea behind CI servers was that when you push to trunk, you were never sure if there would be an integration problem. So if someone pulled trunk, they might get garbage. So the CI server was there so that you could get a visual indication of whether or not it was safe to pull trunk. And if it went red the whole team would instantly take a look to see what happened. It's a team based approach rather than an individual approach.