Mangalord/CLAUDE.md

CLAUDE.md

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

Project

Mangalord is a manga / comics reader. Users browse, search, read, bookmark, and upload manga. The same HTTP API is consumed by both the SvelteKit frontend and external bots/scripts — there is no separate "bot API" or "internal API." Deployment is a single server via Docker Compose.

Stack

• Backend: Rust, axum 0.7, sqlx 0.8 (Postgres), tokio
• Database: Postgres 16
• Frontend: SvelteKit 2 with Svelte 5 runes, TypeScript, Vite
• Storage: Storage trait + LocalStorage impl. S3 and friends are planned implementations, not refactors.
• Tests: cargo test (unit + integration via #[sqlx::test]), Vitest (frontend unit), Playwright (E2E)

Development workflow rules

These rules apply to every change. They are not negotiable per-task — if a change can't be made under them, raise the conflict before writing code.

TDD

Tests describing the expected behaviour are written before the implementation, in the same commit or one immediately preceding. A commit that adds production code without a corresponding test (or that updates a test only after the fact to match what was built) does not meet this bar — split it.

See TDD workflow below for picking the right test level.

Git

• One branch per logical change, prefixed by intent: feat/<slug>, bugfix/<slug>, chore/<slug>, docs/<slug>, refactor/<slug>, test/<slug>. Never commit directly to main.
• Commit messages follow Conventional Commits (feat:, fix:, chore:, docs:, refactor:, test:). One concern per commit.
• Each branch lands via a reviewed PR (self-review counts when working solo; the diff must still be read end-to-end before merge). Squash-merge into main to keep history linear.
• Do not push main directly, do not force-push shared branches, and do not bypass hooks.

Semantic versioning

The project version is tracked in backend/Cargo.toml and frontend/package.json and bumped on every merge to main:

• feat: → bump minor
• fix: / bugfix: → bump patch
• breaking change (only valid before 1.0, otherwise needs a major bump after 1.0) → bump minor while under 1.0
• chore: / docs: / test: / refactor: with no behaviour change → no bump

While the project is pre-release the version stays below 1.0.0. The 1.0.0 release happens only at the user's explicit instruction — do not bump to or past it autonomously.

Both manifests must stay in lockstep (same version string).

TDD workflow

The project is developed test-first. For each change:

1. Write a failing test at the right level.
2. Implement the minimum to make it pass.
3. Refactor with tests green.

Pick the level deliberately:

• Pure logic / mappers / validation → unit test next to the code. In Rust: #[cfg(test)] mod tests in the same file. In the frontend: a sibling *.test.ts.
• Anything that touches the DB → integration test in backend/tests/, using #[sqlx::test(migrations = "./migrations")]. Each test gets a fresh, migrated database.
• Cross-component user journeys → Playwright in frontend/e2e/. Mock the network at the Playwright route level when the journey doesn't require a real backend.

Run these before claiming a change works:

(cd backend && cargo test)
(cd frontend && npm test)
(cd frontend && npm run test:e2e)   # needs dev server, see playwright.config.ts

Backend integration tests require DATABASE_URL to point at a Postgres where the test user can CREATEDB (the #[sqlx::test] macro provisions a fresh database per test).

Backend layout

Hexagonal-ish layering. Handlers depend on repo and storage, never the other way around. This is the seam new extensions plug into.

• backend/src/domain/ — pure data types, no I/O. Add new types here first.
• backend/src/repo/ — DB access functions taking &PgPool. Plain async fns rather than a repository struct; tests target them directly.
• backend/src/storage/ — Storage trait + LocalStorage. Add S3Storage here when needed, do not branch on backend type in handlers.
• backend/src/api/ — axum handlers and route wiring. One module per resource.
• backend/src/app.rs — AppState and router assembly. Integration tests use the same router(state) function with a test AppState.
• backend/src/error.rs — AppError is the single error type returned by handlers. New variants map to status codes in IntoResponse.

When adding a new resource:

1. Add a migration backend/migrations/NNNN_<name>.sql.
2. Add the domain type in backend/src/domain/.
3. Add repo functions in backend/src/repo/.
4. Add handlers in backend/src/api/<resource>.rs and merge in backend/src/api/mod.rs.
5. Add integration tests in backend/tests/, reusing backend/tests/common/mod.rs.

Database access

Queries use sqlx::query_as::<_, T>(...) (runtime-checked) with #[derive(FromRow)] on the domain types, so the project builds without a live DB. If you want compile-time SQL checking later, switch to sqlx::query!/query_as! macros and commit a .sqlx directory via cargo sqlx prepare.

Migrations live in backend/migrations/ and run automatically at startup via sqlx::migrate!.

Storage trait

Do not call tokio::fs or any filesystem API from handlers. Go through state.storage (the Storage trait). Keys are /-separated paths; the local backend rejects .. and empty segments. Suggested key layout:

• mangas/{manga_id}/cover.{ext}
• mangas/{manga_id}/chapters/{chapter_id}/pages/{nnnn}.{ext}

Frontend layout

• frontend/src/lib/api/ — typed API client. All backend calls go through here, not raw fetch in components. The base URL is import.meta.env.VITE_API_BASE, defaulting to /api. Two layers route /api/* to axum depending on environment:
  • npm run dev uses the Vite proxy in vite.config.ts to forward /api to http://localhost:8080.
  • Production / adapter-node uses frontend/src/hooks.server.ts to reverse-proxy /api/* to BACKEND_URL (compose wires http://backend:8080). The browser only ever talks to the SvelteKit container on :3000, so cookies stay same-origin and CORS_ALLOWED_ORIGINS can stay empty.
• frontend/src/routes/ — SvelteKit routes.
• Use Svelte 5 runes ($state, $derived, $effect, $props). Do not use the legacy let-reactive syntax or on:event= directive form — prefer onevent={...}.
• The Node adapter is configured for production; npm run build && node build is what the Dockerfile runs.

Common commands

# Full stack (compose), production-like
docker compose up --build

# Local dev: Postgres in compose, backend + frontend native
docker compose -f docker-compose.dev.yml up -d
(cd backend && cargo run)
(cd frontend && npm run dev)

# Backend tests
(cd backend && cargo test)
(cd backend && cargo test --test api_mangas)         # single integration test file
(cd backend && cargo test list_is_empty_initially)   # single test by name

# Frontend tests
(cd frontend && npm test)                            # vitest, all
(cd frontend && npx vitest run src/lib/api/mangas.test.ts)  # single file
(cd frontend && npm run test:e2e)                    # playwright (auto-starts vite)

Extension points

These are first-class slots in the architecture. When adding any of them, plug into the existing seam rather than building parallel infrastructure.

• Tags / lists: new tables joined to mangas. New domain, repo, and api modules; the existing manga endpoints do not need to change.
• Full-text / fuzzy search: enable pg_trgm in a migration and add a GIN index on mangas.title; swap the WHERE in repo::manga::list to use % operator or tsvector. The API shape (?search=...) does not change.
• OCR / autotagging: a background worker (a separate binary or a tokio task spawned in app::build) that reads pages from storage::Storage and writes tag rows. Do not couple OCR to upload handlers — it runs asynchronously.
• S3 storage: add storage::S3Storage implementing Storage. Branch in app::build based on a config field (e.g., STORAGE_BACKEND=s3). Handlers do not change.
• Auth: an axum middleware producing a CurrentUser extractor. Bots use an API token header, browser users a session cookie — both should populate the same extractor so handlers stay backend-agnostic. Until this lands, treat all endpoints as unauthenticated (this is acknowledged technical debt, not a final design).