Ask AI to find the weakest tests. :)

No joke: it works for me. I have a 45kLOC prod code (just code, no comments, no blanks), tested by a 30kLOC test code containing 1600 tests (that run in 30secs).

I helped with the test infrastructure/architecture. Sometimes I had to write the first few tests of a particular kind, but now Claude TDDs for me.

A fair share of my CLAUDE.md instructs in how I like my tests, when to write them (first), different types of tests (unit, faked-services, db, e2e, etc.)

Asking Claude to find weak tests has helped a lot in getting here. I also do review AI-gen'd code, pretty much line-by-line, before accepting it.