Kerbside Car Share

1. Purpose

A small private web app that lets up to 10 neighbours rent each other’s cars. Owners list cars with prices, locations and the times they’re available; renters browse (as a list or on a map), see when each car is free, and book it.

2. Scope

3. Users & roles

Member — anyone with an account. Every member can be both:
- Owner — lists one or more cars.
- Renter — books other members’ cars.

4. User stories

Accounts

US-01 As a neighbour, I can create an account with a username, display name and password so I can use the app.
US-02 As the organiser, I want sign-ups capped at 10 members (configurable) and optionally protected by an invite code, so only our neighbourhood can join.
US-03 As a member, I can log in and out; my session stays logged in for 14 days.

Browsing

US-10 As a renter, I can see all listed cars with make, model, year, seats, fuel, transmission, colour, photo, hourly and daily price, and owner.
US-11 As a renter, I can filter cars by text, minimum seats, fuel type, maximum hourly price, and a from/to time (showing only cars free for that whole period, with the price for it).
US-12 As a renter, I can switch to a map that shows each car’s location as a pin labelled with its hourly price; clicking a pin shows details and a “Details & book” button.
US-13 As a renter, I can open a car and see a 7-day availability timeline (available vs booked), the list of available slots, and the booked slots.

Booking

US-20 As a renter, I can pick a pick-up and return time and see the total price before confirming.
US-21 The system must reject a booking that is outside the owner’s available times, overlaps another booking, starts in the past, ends before it starts, or is for my own car.
US-22 As a renter, I can see my trips (upcoming, in progress, completed, cancelled) and cancel ones that haven’t finished.
US-23 As an owner, I can see bookings of my cars (with renter name and note) and cancel them if needed.

Owning

US-30 As an owner, I can add a car with its details, a photo URL, prices, pick-up address and a location picked on a map (or “use my location”).
US-31 As an owner, I can change the price per hour / per day at any time. Existing bookings keep the price they were booked at.
US-32 As an owner, I can add or remove available time slots, including a one-click “every day 08:00–20:00 for a week”. Overlapping/adjacent slots are merged automatically.
US-33 As an owner, I can unlist a car temporarily (hidden from others) or delete it if it has no upcoming bookings.
US-34 Only the owner can change or delete their car and its slots.
US-35 As an owner, I can upload a photo of my car (JPEG/PNG/WebP, up to 5 MB) or paste a link to one, and replace or remove it later.
US-36 As a renter, I see each car’s photo on the browse cards, in map pop-ups and on the car’s detail view, with the photographer credited where the licence requires it.

5. Pricing rule

total = whole days × daily price + min(leftover hours × hourly price, daily price); partial hours round up. Example at 10/h, 50/day: 3h → 30; 8h → 50 (capped); 26h → 70.

6. Non-functional requirements

| ID | Requirement | |—|—| | NFR-1 | Runs on one ordinary PC/laptop or a small cloud instance; ≤10 users. | | NFR-2 | One dependency (Express); database is a single SQLite file — easy to back up. | | NFR-3 | Passwords hashed with scrypt + per-user salt; sessions in HttpOnly SameSite cookies. | | NFR-4 | Works on phone screens (responsive layout) and in light/dark mode. | | NFR-5 | Map uses OpenStreetMap — no API key or cost. | | NFR-6 | All server input validated; errors returned as friendly messages. | | NFR-7 | Renter identities are only shown to the car owner and the renter themselves. |

7. Acceptance criteria

All user stories above are covered by the checks in TEST_PLAN.md; the automated suite (npm test) must pass.