Below is an excerpt of Fundamentals of Software Architecture, page 65, which I am reading:
The instability metric determines the volatility of a code base. A code base that exhibits high degrees of instability breaks more easily when changed because of high coupling. For example, if a class calls to many other classes to delegate work, the calling class shows high susceptibility to breakage if one or more of the called methods change.
The chapter exposes a couple of metrics to help architects understand the code base.
Reading that passage, I instantly cross checked that with Dependency Injection - which, in my understanding, is a design principle devised to provide low coupling and testability.
If that is right, aren't DI and Instability metric contradictory? DI encourages delegating responsibilities to dependencies (whenever this makes sense/does not impair cohesion) - while Instability seems to frown on doing that - because that makes the component less stable, since it is more susceptible to break.
Do I misunderstand this metric, DI, or both?