[LouisSayers]

This is the approach I take as well, and also think about it in terms of “setting things in stone”.

When you’re starting out a project and “discovering” the structure of it, it makes very little sense to lock things in place, especially when manual testing is inexpensive.

Once you have more confidence in your structure as it grows you can start hardening it, reducing the amount of manual testing you do along the way.

People that have hard and fast rules around testing don’t appreciate the lifecycle of a project. Different times call for different approaches, and there are always trade offs. This is the art of software.