In particular that book considers the problem of retrofitting an existing system to have good tests, so it covers all the bases for a system that runs in production and is in front of customers. Feathers is particularly an advocate for fast tests, he thinks a 1ms test is a little slow.
A counter to that is some subsystems are prone to race conditions and a necessary test could be to stress the subsystem with 200 threads. This automated test is of great value but takes 30 seconds to run which is quick to do once but adds up to slower development cycles when you make any change.
https://www.amazon.com/Working-Effectively-Legacy-Michael-Fe...
In particular that book considers the problem of retrofitting an existing system to have good tests, so it covers all the bases for a system that runs in production and is in front of customers. Feathers is particularly an advocate for fast tests, he thinks a 1ms test is a little slow.
A counter to that is some subsystems are prone to race conditions and a necessary test could be to stress the subsystem with 200 threads. This automated test is of great value but takes 30 seconds to run which is quick to do once but adds up to slower development cycles when you make any change.