Calendar: midnight meetings refused, clashes let through, jumbled free slots and repeated ids

Context

Welcome to the workplace team. The day calendar in booking/ implements both levels in README.md. Since the last release, four reports have come in.

Fix as much as you can in 30 minutes. The checks are graded one by one, so each report you fix counts even if the rest is not done.

CAL-11: Meetings that run until midnight are refused

Report

The late support shift books 22:00 to 24:00 every day. Since the release it gets -1, though the room is empty.

Acceptance criteria

• A booking may end at 1440 (24:00).

CAL-12: A long meeting can be booked over a short one

Report

Room A had a stand-up from 10:00 to 10:15. Someone booked 09:00 to 12:00 in the same room and got an id back.

Acceptance criteria

• A slot that covers an existing booking is refused, as are slots that start or end inside one.

CAL-13: Free slots are wrong when bookings were made out of order

Report

The afternoon was booked before the morning. The free slots list now shows times that are booked.

Acceptance criteria

• free_slots lists free stretches correctly, earliest first, whatever order the bookings were made in.

CAL-14: Ids repeat after a cancel, and bookings disappear

Report

We booked twice (ids 1 and 2), cancelled 1, then booked again: the new booking got id 2, and the old booking 2 vanished from bookings().

Acceptance criteria

• Ids are never reused: each new booking gets the next new id, and no booking replaces another.

Notes

• Run pytest tests/visible. Two tests fail on the current code; not every report has a failing test yet.
• Practice task modelled on a candidate report of a Microsoft calendar booking interview question. Original StackYard code, not the actual question; not affiliated with Microsoft.