This is a draft.
Yeah, yeah. You’re agile. You always test first, you work in tight iterations, you have YAGNI tattooed on your forehead. Good for you. Guess what? You’re building on sand. Do this stuff first:
Tests (and Autotest) With Coverage
Make sure your testing infrastructure works. Write a single sanity test, make it pass and fail, and make sure that your test scripts/tasks, autotest setup, and coverage tools are working correctly.
Deploy/Install/Update an Empty App
If you’re writing a desktop app, write your installer and make sure it’s working. Don’t wait ‘til the last minute! The moment you write a line of code, it’ll be easier to have someone test it if the installer’s functional.
Even better, start by integrating an update system like Sparkle. You may be distributing the empty shell of an app, but now you can automatically update your testers every time you push new changes. And you’re testing your post-release update infrastructure at the same time! Win!
Some of your code is shit. Even in the unlikely event that all your Codes Are Perfect, someone’s code that you depend on is shit. Integrate error reporting at the very beginning, before any users have a chance to make errors. For Rails apps, I use Hoptoad. There are a billion other alternatives, and rolling your own is easy too.
You’re probably not going to be the only person who works on this project. How does the next person in the door get up and running? If the answer is much more complicated than “check out the code and read the README,” you suck.
Start documenting at the very beginning. What should someone run to get started in a fresh checkout? (I like
rake newb) How does deployment work? Where’s the deployment server? How was it configured? How do I stand up another one from scratch? What external services (issue tracking, error reporting) does this app use?
Make sure your initial set of docs answers these questions, and make it clear that keeping them up-to-date is as important as keeping the tests passing.