How does modules solve this problem? If you changed Module A, don't you need to also test every component that depends on that module to account for any possible regression?
> The scenario used to drive this idea is a slippery slope fallacy that tests can take over an hour to run after years.
It doesn't really take much for a project to grow to one hour for tests to run. If you have a CI/CD pipeline that executes tests on every commit and you have 30-40 commits daily, that's 30-40 hours.
Still, I'd rather setup a full 2 machines to run the tests than rather have to deal with selective testing. It might make sense if you have hundreds of commits per day.
> The scenario used to drive this idea is a slippery slope fallacy that tests can take over an hour to run after years.
It doesn't really take much for a project to grow to one hour for tests to run. If you have a CI/CD pipeline that executes tests on every commit and you have 30-40 commits daily, that's 30-40 hours.
Still, I'd rather setup a full 2 machines to run the tests than rather have to deal with selective testing. It might make sense if you have hundreds of commits per day.