FA-85654 / Ride-hailing fare and surge pricing / Member archive

Rider counted in every zone they requested from · case 04

A rider re-requesting after walking to another zone counts twice.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Surge demand counts ride requests [t, rider, zone] in the window (now - window, now]. Each rider counts once, in the zone of their latest request in the window (a later-listed request wins a timestamp tie). Return zone -> count for zones with demand.

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: rider deduplication key	`{"Z1": 1, "Z2": 2}`	`{"Z2": 2}`	Failed

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