# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Tech Stack

- SvelteKit 5 + TypeScript + Bun + Tailwind v4 + better-sqlite3
- Auth via Synology SSO Server (OIDC) using Auth.js

## Development Commands

```bash
bun run dev          # Start dev server
bun run build        # Production build
bun run check        # TypeScript type-check
bun run lint         # ESLint (must pass with 0 errors)
bun run format       # Prettier formatting
bun run test         # Run unit tests (must all pass)
bun run test:watch   # Run tests in watch mode
bun run test:coverage # Run tests with coverage report
```

## Code Quality

### Linting and tests must pass before considering any task complete

After making changes, always verify:
1. `bun run lint` — must exit with 0 errors (warnings are acceptable)
2. `bun run test` — all tests must pass

### Write unit tests after every major feature

When adding or significantly modifying server-side business logic (files under `src/lib/server/`), write corresponding unit tests in a `.test.ts` file alongside the module (e.g. `src/lib/server/lodgings.test.ts`).

Tests use Vitest with an in-memory SQLite database. Use the `setupTestDb()` helper from `src/tests/helpers.ts` to get a fresh DB per test:

```ts
import { setupTestDb } from '../../tests/helpers.js';
import type { Database } from './db/types.js';

let db: Database;
beforeEach(() => { db = setupTestDb(); });
afterEach(() => { db.close(); });
```

Test coverage should include the happy path, optional fields, ownership/authorisation checks, and any relationship linking (e.g. guests, travellers).

### ESLint notes

- `svelte/require-each-key` is set to `warn` — keyless `{#each}` blocks are acceptable where keys are not meaningful
- `@typescript-eslint/no-unused-expressions` is off — the `value;` reactivity-tracking pattern used in Svelte 5 `$effect` blocks is intentional
- Prefix unused variables/args/catch bindings with `_` to satisfy the no-unused-vars rule
- Use `// eslint-disable-next-line svelte/prefer-svelte-reactivity` for `new URLSearchParams()` used as local temporaries (not reactive state)

## DB / Testing Architecture

All server modules import `db` from `$lib/server/db/index.ts`. In tests, `_setDb()` is used to inject an in-memory SQLite instance, bypassing the `$env/dynamic/private` SvelteKit virtual module entirely. Never call `_setDb` in production code.

SvelteKit virtual modules (`$env/dynamic/private`, `$app/paths`) are stubbed via path aliases in `vitest.config.ts`.