TDD vs. Unit testing [closed]

My company is fairly new to unit testing our code. I've been reading about TDD and unit testing for some time and am convinced of their value. I've attempted to convince our team that TDD is worth the effort of learning and changing our mindsets on how we program but it is a struggle. Which brings me to my question(s).

There are many in the TDD community who are very religious about writing the test and then the code (and I'm with them), but for a team that is struggling with TDD does a compromise still bring added benefits?

I can probably succeed in getting the team to write unit tests once the code is written (perhaps as a requirement for checking in code) and my assumption is that there is still value in writing those unit tests.

What's the best way to bring a struggling team into TDD? And failing that is it still worth writing unit tests even if it is after the code is written?

EDIT

What I've taken away from this is that it is important for us to start unit testing, somewhere in the coding process. For those in the team who pickup the concept, start to move more towards TDD and testing first. Thanks for everyone's input.

FOLLOW UP

We recently started a new small project and a small portion of the team used TDD, the rest wrote unit tests after the code. After we wrapped up the coding portion of the project, those writing unit tests after the code were surprised to see the TDD coders already done and with more solid code. It was a good way to win over the skeptics. We still have a lot of growing pains ahead, but the battle of wills appears to be over. Thanks for everyone who offered advice!


If the team is floundering at implementing TDD, but they weren't creating any Unit Tests before...then start them off by creating Unit Tests after their code is written. Even Unit tests written after the code are better than no Unit Tests at all!

Once they're proficient at Unit Testing (and everything that comes with it), then you can work on getting them to create the tests first...and code second.


It is absolutely still worth writing the unit tests after code is written. It's just that sometimes it's often harder because your code wasn't designed to be testable, and you may have overcomplicated it.

I think a good pragmatic way to bring a team into TDD is to provide the alternative method of "test-during development" in the transition period, or possibly in the long-term. They should be encouraged to TDD sections of code that seem natural to them. However, in sections of code that seem difficult to approach test-first or when using objects that are predetermined by a non-agile A&D process, developers can be given the option of writing a small section of the code, then writing tests to cover that code, and repeating this process. Writing unit tests for some code immediately after writing that code is better than not writing any unit tests at all.


It's in my humble opinion better to have 50% test coverage with "code first, test after" and a 100% completed library, than 100% test coverage and a 50% completed library with TDD. After a while, your fellow developers will hopefully find it entertaining and educational to write tests for all of the public code they write, so TDD will sneak its way into their development routine.