kcov works here once invoked correctly, so shell coverage is measurable
after all. shell_coverage.sh wraps it as a gate; the XML parsing lives in
shell_coverage_report.py per the rule against inlining another language's
logic in a shell script.
Two kcov traps are documented in the wrapper because both fail silently.
It must be handed the test script DIRECTLY: given `bash script.sh` it
instruments the bash binary, finds no shell source, and reports 0/0 at
0.00% -- indistinguishable from "nothing is covered". And per-line detail
exists only in cov.xml; coverage.json carries the percentage alone, so it
cannot say which lines are missing.
First measurement put dns_iptables.sh at 68/74 = 91.89%, with all six
uncovered lines in error and edge branches: chain creation failing, jump
insertion failing, the stale-jump de-dupe log, and the v6 trusted-resolver
ACCEPT. The stub grew failure injection and jump seeding to reach them,
and four new cases take it to 74/74 = 100.00%.
The gate fails closed: deleting the three ensure_chain failure cases drops
it to 93.24%, names lines 23, 24, 37, 40, 41, and exits 1.
Not wired into pre-commit -- kcov is absent on CI, and most shell files
here have no test at all.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011w2Pj4Ek3ZNMQVYcFHgXDY
