Per bot review on PR #1852 (comment 5011643190): two changes in the
recent delta had zero test coverage, which the repo's TDD policy
(AGENTS.md § Test-First Development) requires for both net-new UI
helpers and bug fixes on existing UI.
- scopeCellHtml (public/app.js): unit tests for all three states
(non-transport dash, resolved region, unresolved "unknown") plus an
XSS-escaping check.
- Column-prefs backfill (public/packets.js): extracted the inline
reconciliation logic into a standalone reconcileVisibleCols(),
exposed via _packetsTestAPI like the rest of packets.js's pure
helpers, and unit tested directly instead of only through the DOM.
Writing the test surfaced a real bug in the original backfill: it
couldn't distinguish "column didn't exist yet" from "user explicitly
unchecked this column" — both look identical as a missing key in the
saved array, so any existing column a user had hidden (e.g. Observer)
would get silently resurrected on next page load. Fixed by persisting
a second "known columns" baseline (packets-visible-cols-known)
alongside the visibility array: a missing key only gets backfilled as
newly-visible if it's also absent from the known-columns baseline: a
pre-existing key missing from the saved array is a deliberate user
choice and stays hidden. Falls back to the pre-#1852 column list for
visitors whose saved prefs predate persisting the baseline at all.
Also registers scopeCellHtml in .eslintrc.json's cross-file globals
list (same treatment as transportBadge) — packets.js referencing it
was tripping no-undef since app.js and packets.js are separate
non-module scripts.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
