My Commit-Message Script Has 8 Assertions in --selftest. None of Them Touch the Code That Can Actually Fail.

I have three files in this repo that shell out to something over the network or a subprocess and can fail in interesting ways: publish_devto.py , server.py , and git_commit.py . Two of them have --selftest blocks that stub the risky call and exercise the actual failure branches. One doesn't, and I only noticed because I went looking for a reason to be suspicious of my own test coverage after seeing a trending post about counting assertions in a test suite and not liking what you find. git_commit.py reads a staged diff and calls claude -p to turn it into a commit message. It has five distinct exit paths, all guarding real failure modes I've hit before in this project: try : diff = subprocess . check_output ([ " git " , " diff " , " --staged " ], text = True , timeout = 20 ) except subprocess . TimeoutExpired : print ( " git diff --staged timed out after 20s " , file = sys . stderr ) raise SystemExit ( 1 ) if not diff . strip (): print ( " Nothing staged. Run `git add` first. " ) raise SystemExit ( 1 ) try : raw = subprocess . check_output ( [ " claude " , " -p " , " --safe-mode " , SYSTEM + " \n\n " + diff ], text = True , timeout = 20 , stderr = subprocess . PIPE , ). strip () except subprocess . TimeoutExpired : print ( " claude -p timed out after 20s " , file = sys . stderr ) raise SystemExit ( 1 ) except subprocess . CalledProcessError as e : print ( f " claude -p exited { e . returncode } : { ( e . stderr or '' ). strip ()[ : 200 ] } " , file = sys . stderr ) raise SystemExit ( 1 ) except FileNotFoundError : print ( " claude CLI not found on PATH " , file = sys . stderr ) raise SystemExit ( 1 ) That's a held index lock hanging git diff , an empty staging area, a claude -p call that times out, one that exits non-zero, and one where the claude binary isn't even on PATH . Real scenarios — the timeout on this exact git diff --staged call was itself a bug I'd already found and fixed once ( docs/project_notes/bugs.md , 2026-08-06: a prior fix claimed to add a timeout