FA-85399 / Ride-hailing fare and surge pricing / Member archive

Sales tax charged on tolls and airport fees · case 04

Airport trips show tax on the pass-through fees.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Cents throughout. Surge (tenths) multiplies only base+distance+time, rounded half up. A percentage promo discounts the surged amount (floor), capped at promo cap cents. The booking fee is added after the discount. Tax (basis points, rounded half up) applies to surged - discount + booking fee; tolls and airport fees are passed through untaxed and unsurged.

Why this case matters

Ride-hailing prices are computed per trip at scale; ordering, unit and boundary slips become systematic over- or under-charging.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: tax base pass-throughs	`{"discount": 5, "surged": 2868, "tax": 287, "total": 3770}`	`{"discount": 5, "surged": 2868, "tax": 256, "total": 3739}`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.