[still_grokking]

Throwing away and rewriting tests is work (== negative value).

Testing implementation details is always contra productive. Have you watched the video? (I'm not recommending videos often, as I think writings have more value per time-unit, but this talk is a kind of classic on that topic.)

[darkerside]

Sorry, I can't accept that a one hour video is the cost to participate in this conversation. I don't disagree that there is a cost associated with doing this, but the cost is so much smaller than it used to be that it can be economical now.

Implementation details are in the eye of the beholder IMO. I'm open to reasons why that's not the case here.