Tiny Inventory

A minimal inventory management system tracking stores and the products they carry.

Run with Docker

docker compose up --build

Then open http://localhost (port 80).

Local development

Note: The server uses better-sqlite3. On Windows you may need Visual Studio Build Tools. Use Docker otherwise.

# Terminal 1 - Backend
cd server && npm install && npm run dev

# Terminal 2 - Frontend
cd web && npm install && npm run dev

• API: http://localhost:3001
• Web: http://localhost:5173 (proxies /api to backend)

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API

Method	Route	Description
GET	/api/stores	List stores
GET	/api/stores/:id	Get store
POST	/api/stores	Create store
PUT	/api/stores/:id	Update store
DELETE	/api/stores/:id	Delete store
GET	/api/stores/:id/summary	Non-trivial: total value, by-category breakdown, low-stock count
GET	/api/products?storeId=&category=&minPrice=&maxPrice=&inStock=&page=&limit=	List products (filtered, paginated)
GET	/api/products/:id	Get product
POST	/api/products	Create product
PUT	/api/products/:id	Update product
DELETE	/api/products/:id	Delete product

Error shape

{ "error": "string", "details": {} }

Scenario	Status
Missing resource	404
Validation failure	422
Unexpected	500

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Decisions & Trade-offs

Tech stack

• Backend: Fastify + TypeScript — built-in schema validation, lean.
• Database: SQLite via Drizzle ORM — zero deps, migrations, type-safe queries.
• Frontend: Vite + React + TanStack Query + Tailwind — Query handles loading/error/stale; Tailwind for readable styles.
• Testing: Vitest + Supertest (server) + React Testing Library (frontend).

Data model

Flat: Store and Product (product has storeId, quantity). Category is a string enum (Produce, Dairy, Bakery) enforced at API. No separate Category table.

Non-trivial operation

GET /stores/:id/summary returns:

• Total inventory value (SUM(price × quantity))
• Per-category breakdown
• Low-stock count (quantity < 10)

Pagination & filtering

Offset-based (page + limit). Cursor-based is better for large datasets; offset is simpler for this scope. All filters optional and composable.

Architecture

• Backend: Thin routes, services hold logic, single error-handler middleware.
• Frontend: api/ (typed fetch), hooks/ (TanStack Query wrappers). Pages use hooks only.

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Testing

cd server && npm test
cd web && npm test

Layer	What's tested
API	Happy paths, 404, 422 via Supertest
Frontend	100% line/statement coverage

Run cd web && npm run test:ci for coverage report. E2E tests (Playwright) skipped at this scope.

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If I Had More Time

1. E2E tests — Playwright for create-store, add-product, view-summary flows.
2. Optimistic updates — TanStack Query mutations with rollback on failure.
3. Debounced filters — Reduce API calls while typing in product filters.