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Add GET /v1/skus/{id}/reservations (list by SKU, filterable by status) — feature ticket · 10xDebuggable

enhancementadvancedP3internal/handler/sku_handler.go, internal/handler/server.goLevel 2 · Implement a feature25 XP1–2 hours

Add GET /v1/skus/{id}/reservations (list by SKU, filterable by status)

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Business impact

There is no way to discover a SKU's reservations short of already knowing each individual reservation id. Support staff investigating "what's holding this SKU's stock right now" (or "what happened to this customer's order") have no endpoint to call.

Problem

The route is already wired up and Server.ListReservationsForSKU exists only as a panicking TODO(ticket-20) stub.

Current behavior

GET /v1/skus/{id}/reservations currently returns a 500 because Server.ListReservationsForSKU panics with "TODO(ticket-20): Server.ListReservationsForSKU not implemented".

Expected behavior

GET /v1/skus/{id}/reservations?status= lists reservations against a SKU, optionally filtered by status (active, committed, expired, released); an empty/omitted status returns all of them.

Steps to reproduce

go test ./tickets/tests/... -run TestTicket20 -v
Observe: GET /v1/skus/{id}/reservations returns 500 -- Server.ListReservationsForSKU is still the panicking "TODO(ticket-20)" stub.

Why this matters

The route is already wired up and Server.ListReservationsForSKU exists as a stub -- this is a straightforward query against the reservations table filtered by sku_id and, optionally, status -- the same query-param-handling shape ListLedger right above it already demonstrates for after/limit.

Suggested approach

Look at ListLedger in the same file for the pattern of reading an optional query param and building the WHERE clause conditionally, and GetReservation in internal/handler/reservation_handler.go for the row-to-JSON shape a single reservation already uses.

Acceptance criteria

GET /v1/skus/{id}/reservations with no status returns every reservation for that SKU
?status=active returns only reservations with that status
tickets/tests/ticket20_test.go passes

Verification

TEST_DATABASE_URL=postgresql://... go test ./tickets/tests/... -run TestTicket20 -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 feat/list-reservations-endpoint

Fix it and commit

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

Push the branch

$git push -u origin feat/list-reservations-endpoint

Submit it below

Paste your fork URL and the branch name, with a short write-up of the root cause.

Submit your fix

Questions

Stuck on something?

Ask about anything unclear in the ticket — the maintainer and anyone who has solved it can answer. Please don't post full solutions.

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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 .

SKIP LOCKED

http://localhost:8081

localhost:5434

flash-sale

everyday-widget

curl localhost:8081/healthz

go run ./cmd/loadtest -url http://localhost:8081 -sku flash-sale -concurrency 10000

export TEST_DATABASE_URL=postgresql://inventory:inventory@localhost:5432/inventory_test?sslmode=disable
go test ./tickets/tests/... -run TestTicket24 -v   # a single ticket
./tickets/run_tickets.sh                           # all 25, clean pass/fail summary