Distance confidence
- Every distance surface takes the figure AND its "Approx." marker from one
FuelStore.stationDistanceDisplay call (station rows, detail sheet, widget,
Live Activity, watch, Siri), so a surface can never mark one figure approximate
while showing a routed one. Radius filters and Closest ordering test that same
displayed distance, so no row can read a distance outside the radius that
filtered it (the reported "14.6 mi inside a 10-mile list").
Accurate distances (Settings -> Distances, default off)
- Off: the browse layer serves the straight line, marked Approx., for every row,
so two installs agree to the metre and the app makes no route requests at all.
- On: routed distances for the whole search area, unmarked, served only from a
COMPLETE set anchored within 600 m — a partial fill reverts every row at once
rather than mixing road and straight-line bases.
- Best Value maths sits deliberately outside the toggle: it keeps using measured
road routes and its own confidence marking, so money figures never move with
the switch.
- Fills run only while the toggle is on and the app is frontmost; capacity raised
to 600 stations per pass; completeness tolerates pins Apple Maps has no route
for, which otherwise left an area permanently incomplete and the whole list
stuck on estimates.
Performance (the reported slowdown switching to Closest / launching with it)
- FuelStore.accurateDistancesEnabled was a UserDefaults(suiteName:) read per
call: a synchronous cfprefsd round-trip measured at ~1.9 us, ~200k calls per
Closest sort. Memoised, with the setter keeping it in step.
- Both keyed sorts decorate their keys — one distance per station, carried as an
index instead of copying whole stations into the decorated array — and the
comparison baseline plus per-station journeys now come from ONE pass instead of
two full scans per tab. The Stations tab also reuses its single sorted list for
the count and the TOP badge instead of sorting the country three times.
- Measured on iPhone SE (7,914-station Closest pool): sort 36.6 ms -> 17.1 ms per
list, Cheapest 6 ms, Best Value 11 ms.
- DEBUG probes: FB_PERF list timing, FB_PERF_BENCH toggle-read benchmark, and
FB_DIST_FOCUS now reports the served value, marker and mode (and re-prints when
a fill lands). FB_ACCURATE_DISTANCES / FB_SORT_MODE env forms for devices, where
devicectl eats a leading-dash argument.
Tests: 198, 0 failures. Device and simulator Debug builds green.
Calculation audit (brief config: 30 MPG imperial, £60 fill-up, baseline
Rontec Shelf 171.9p at 0.4 mi):
- One mile<->kilometre constant pair (kilometresPerMile 1.609344,
metresPerMile 1609.344) replaces the mixed 1609.34 / 0.621371 / 1.60934
used in the savings path. Effect ~2 ppm (invisible), but the conversions
are now auditable in one place.
- New FuelSavingsCalculationAuditTests (20 deterministic tests, no live
MKDirections) pins the brief's three stations - Tesco 170.9p/2.0 mi,
MFG Hare & Hounds 172.9p/2.8 mi, PGG Napoleon 171.9p/2.8 mi - plus
imperial-vs-US gallon, MPG and budget scaling, the break-even tolerance
boundary, the nearer-candidate clamp, route-unavailable, mixed-basis
estimates and display-rounding boundaries.
- Formula unchanged, and verified correct: fixed quantity (budget / baseline
price), pump saving, round-trip extra distance clamped at zero, travel fuel
priced at the candidate station, +/-5p break even, baseline labelled
"Closest station", sorting on the unrounded net saving. The brief's "£0.18"
for Tesco is the rounded 1 dp extra-distance caption (2.02-2.05 mi reads as
"2.0 mi"), not a rounding bug in the money.
UI (uncommitted since d7a0ecb):
- Done bar drawn in the bottom safe area from keyboard notifications:
.toolbar(placement: .keyboard) is device-dependent (present on the 15 Pro,
absent on the SE on the same iOS build).
- Favourite star in the More-info heading, wired to the same fuel-scoped
toggle as the listing rows at all three call sites.
- CHEAPEST/TOP badge moved above the price so it reads as part of it.
- Listing rows carry the real session fill-up amount instead of a hard zero
(the compact banner does not print it today; a future row layout would).
153 tests, 0 failures. Simulator and device builds succeed.
FuelBoard Contributor
FuelBoard Contributor