The frontend was classic scripts sharing one global scope, with a
load-order contract enforced only by comments (leaflet -> nav ->
shared -> mappicker -> page) and hand-rolled window.Thermograph /
window.LocationPicker namespaces. Page scripts now import what they use;
the dependency graph replaces the ordering contract, and no app globals
remain (Leaflet stays a classic script / global L, loaded first).
nav.js had grown four concerns; it's now three single-purpose modules:
- nav.js: last-location memory + header view-links + locHash.
- units.js: the °F/°C toggle and unit-aware formatting. The compare
special case is gone — pages that want the toggle import units.js;
compare simply doesn't.
- cache.js: the IndexedDB response cache, SWR getJSON, bundle-seeded
view prefetch and neighbor warming. prefetchViews(lat, lon, ownViews)
now takes the calling page's own view names instead of a page-identity
map (VIEW_OWN) — adding a page no longer means editing this module.
The slice->URL map stays here as bundle-contract knowledge.
frontend/package.json ({"type": "module"}) makes CI's node --check
parse the files as modules.
Verified: node --check on all files as modules; 108 backend tests;
headless-Chromium smoke across all five pages against live data — zero
console/page errors, all render assertions pass (cards, chart, calendar
grid + metric switch, ladders, compare ranking, legend scales).
The page scripts each re-declared the shared presentation layer — the tier
color table existed in four places (app.js, calendar.js, day.js, style.css)
and the scale label tables in three (plus legend.html's own drifting copy),
alongside per-page copies of the dryness ramp, formatters, ord, todayISO,
esc, the weather icons/summary, month helpers and the 2-year range chunker.
~240 duplicated lines deleted (net -236 with the new module included).
- frontend/shared.js (IIFE, extends window.Thermograph): tier colors read
from style.css's :root custom properties at load — the CSS is now the
single source of truth; the JS map exists only because inline-SVG work
(chart + PNG export) needs literal values, with hex fallbacks for a
missing stylesheet. Plus SCALE_TEMP/SCALE_RAIN, drynessColor, fmt*, ord,
todayISO, esc, placeLabel, month/chunk date helpers, clickOpensPicker,
and the weatherType summary (dsr-aware; the day page just omits dsr).
- nav.js: wrapped in an IIFE — its ~15 top-level functions were globals in
the shared classic-script scope, and a leaked locHash collided with page
destructuring (caught by the browser smoke, not by node --check).
locHash is now exported and used by all 8 former hand-built hash sites.
- mappicker.js: initFindButton/setFindLabel replace the Find-button block
each page rebuilt.
- legend.html renders its scales from the shared tables, so the guide can
no longer drift from what the app shows.
Verified: node --check on all JS; 108 backend tests; headless-Chromium
smoke over all five pages against live data — no console/page errors,
legend rows 9/9, weekly 7 cards + colored chart/key/table + metric toggle,
calendar grid + key + metric switch, day 7 ladders + weather icon,
compare seeded rank card.
