The two Fuel Savings figures and the in-list fill-up control were text
fields. A typed figure could sit outside the slider's own bounds, so the
control and the number it claimed to show could disagree, and the decimal
pad needed a Done button to escape.
- Settings: "Average fuel economy" and "Typical fill-up" are now sliders
with a read-out ("45 MPG", "£40" / "40 L") in place of the field. The
warning copy reads "Set a realistic..." rather than "Enter...".
- FuelSavingsAdjustmentView (shared by the Stations Worth-the-Drive header
and the Favourites tab) drops its text field and gains the same read-out;
the typed-value machinery and the -focusFillAmount QA hook go with it.
- Slider bounds live in FuelSavingsCalculator (fillAmountSliderRange/Step,
mpgSliderRange/Step) so the Settings control and the in-list control can
never offer different ranges, and the fill-up slider range stays inside
the calculator's validity ceiling (asserted by test).
- Two tests pin those invariants: every slider position is a valid amount,
and both MPG bounds are valid MPG values. 155 tests, 0 failures.
- Comments that described the removed fields were updated; the keyboard
Done-bar plumbing is kept (no numeric field remains in the app, so it can
no longer fire) rather than deleted, so any field added later still has an
escape route.
Verified on the simulator: Settings shows "Average fuel economy / 45 MPG"
with no field, and the Worth-the-Drive fill-up control shows the unit picker
with a "£40" read-out and a slider. The Settings "Typical fill-up" row sits
below the fold on every simulator available here (and synthetic input cannot
scroll it), so those pixels are unverified.
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.
Optional Fuel Savings feature (off by default): vehicle MPG in UK imperial gallons, fill amount in pounds or litres, persisted through the existing keychain/app-group store. Ranks the WHOLE station pool by estimated net saving (fuel-price saving at each pump minus the extra return-trip driving cost) using MapKit road distances with a straight-line fallback marked (est.).
The closest station with a valid price for the selected fuel is the comparison baseline and is labelled "Closest station"; other rows read "Save £X.XX after travel" / "£X.XX worse off after travel" / "Break even". Labels live in the shared model so they are unit-tested. The TOP badge still marks the cheapest pump price and reads "CHEAPEST" when the list is ranked by net saving.
Road routing now prioritises the Worth-the-Drive candidates plus the baseline and merges cache entries instead of replacing them, so far-out stations get real routes rather than permanent straight-line estimates. Numeric fields gain a Done button above the keypad (decimalPad has no Return key); the fill-up control is hidden unless the feature is configured; Favourites shares one session fill amount with the station list. 131 tests.