At PyCon '08, I gave a talk on testing and the OLPC project where I referred to the "Testing Death Spiral". My accompanying slide, which aimed to be simple rather than comprehensive, had this scenario:
1.
Write a bunch of code & manually test it.
(Good so far.)
2.
Start adding features over here.
3.
Watch code break over there.
4.
Rinse, lather, repeat
(Where do you think this ends?)
