POST /v1/reservations/{id}/commit always returns 404

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Business impact

This is the checkout endpoint -- the one that turns a hold into a sale. With this bug, it fails 100% of the time, for every reservation, no matter how valid the id. Every payment success would be followed by a failed commit call, always reported as "reservation not found" -- a misleading error that would send whoever's debugging it looking in completely the wrong place instead of the real, one-line routing bug.

Problem

POST /v1/reservations/{id}/commit returns 404 Not Found for every reservation id, including ones that were just created and definitely exist.

Current behavior

CommitReservation reads chi.URLParam(r, "reservation_id"), a name that was never registered anywhere -- the route binds that path segment to id, so chi.URLParam returns an empty string and Commit("") is called every time.

Expected behavior

Committing a valid, active reservation id should succeed (200 OK).

Steps to reproduce

go test ./tickets/tests/... -run TestTicket16 -v

Why this matters

The route is registered as POST /v1/reservations/{id}/commit -- chi binds that path segment to the URL parameter named id. CommitReservation reads chi.URLParam(r, "reservation_id"), a name that was never registered anywhere. chi.URLParam returns an empty string for an unbound name, so Commit("") is called every single time -- which can never find a real reservation.

Suggested approach

Compare CommitReservation's chi.URLParam call against GetReservation and ReleaseReservation right next to it in the same file -- they read the same route parameter correctly.

Acceptance criteria

POST /v1/reservations/{id}/commit succeeds for a valid, active reservation id
It still correctly returns 404 for an id that genuinely doesn't exist
tickets/tests/ticket16_test.go passes

Verification

TEST_DATABASE_URL=postgresql://... go test ./tickets/tests/... -run TestTicket16 -v

Hints (0/2)

Try it without hints first — the reading is the exercise.

Working on this ticket

Work on a branch named for the ticket — that's what you'll submit.

Branch off your fork

$git checkout -b fix/commit-wrong-url-param

Fix it and commit

Meet every acceptance criterion, and add a test that would have caught this.

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$git push -u origin fix/commit-wrong-url-param

Submit it below

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Questions

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The project

Inventory Reservation Service

Oversell-proof stock reservations under extreme concurrent contention: 100 units, 50,000 simultaneous "Buy Now" clicks, and exactly 100 must succeed.

Fork on GitHub

Download

Setup

Inventory Reservation Service

git clone <your-fork>
cd GolangDevTraining/inventory
docker compose up --build   # Postgres + 2 hot-reloading app replicas + Adminer

Two app replicas are on by default, not opt-in: the TTL reaper's claiming and the reservation hot path's atomicity guarantee only prove anything interesting with more than one process sharing the same Postgres and the same SKU row. App replica 1 is reachable at ; Postgres at . Seeded on startup: (10 units) and (5,000 units). Verify with and .