This is bouncing against the perpetual "code as text" problem. Put the tests and docs in with the code and you end up going into "scanning" mode. The actionab

This is bouncing against the perpetual "code as text" problem. Put the tests and docs in with the code and you end up going into "scanning" mode. The actionable information density per character is lower. Put the tests and docs outside the code and you (or that obnoxious guy who just changed > to >=) don't update the tests or the docs. In the worst case (cough functional web tests) people tend to disable the tests because it's too much work to get them to conform to the changes and everyone is on fire and babies are dying and this needs to be done in production now.