# Development

How to run Siftlode locally and pass the gate. Conventions for the backend code itself live in
[`backend/app/README.md`](../backend/app/README.md).

## Node

One major, everywhere. `.nvmrc` pins it; the CI container, the `Dockerfile`'s frontend build stage,
`frontend/package.json`'s `engines` and `@types/node` must all match it — and so must the machine you
run the gate on. `frontend/src/lib/nodeEngine.contract.test.ts` fails the gate the moment any of them
drift apart, including when yours is the odd one out. `nvm use` in the repo root picks it up.

This is a contract, not a preference: tsc and vitest read the engine's own `Intl` and web APIs, and
those change between majors — the same currency format renders `$160M` on one and `$160.0M` on the
next. A gate that is green on a major you do not ship is green about nothing.

## Run it locally

The whole stack (Postgres + API + worker) comes up from the localdev compose file:

```bash
docker compose -f docker-compose.localdev.yml up --build
```

Browse at **http://localhost:8080** (Google login works — the OAuth redirect is
`http://localhost:8080/auth/callback`). The API runs `alembic upgrade head` on startup, so the schema
is always current.

For a fast frontend edit loop, run the Vite dev server with HMR against that API:

```bash
cd frontend && npm install && npm run dev   # http://localhost:5173, proxying the API on :8080
```

The dev server also serves the **design lab** at `http://localhost:5173/design-lab`: the open design
decisions and the chosen patterns, rendered with the app's real CSS. It never reaches a production build
(see [`DESIGN.md`](DESIGN.md)).

## The gate

A change is done when all of this is green. CI runs the same checks server-side
(`.gitea/workflows/check.yml`), so "main is always green".

**Backend**

```bash
# lint + format check
python -m ruff check --config backend/ruff.toml backend scripts
python -m ruff format --check --config backend/ruff.toml backend scripts

# tests — pure-logic + the DB-backed integration lane, against an ephemeral Postgres.
# The backend tree is bind-mounted, so it always tests your working files.
docker compose -f backend/docker-compose.test.yml up --build --abort-on-container-exit --exit-code-from test
docker compose -f backend/docker-compose.test.yml down -v
```

The test compose sets `SIFTLODE_TEST_REQUIRE_DB=1`, which turns a would-be silent skip (no DB, or no
ffmpeg) into a hard failure — so the gate can't print green while the DB-backed tests were quietly not
run. Tests that need a database take the `db` fixture (`backend/tests/conftest.py`); the rest are
pure-logic and run without one.

**Frontend** (from `frontend/`)

```bash
npm run typecheck     # tsc x3 (app / node / e2e)
npm run lint          # eslint
npm run format:check  # prettier
npm run knip          # unused exports/deps
npm run test          # vitest
```

## Branching

Trunk-based: branch off `main`, keep the branch gate-green, and land the whole change back to `main`
in one reviewed step. Migrations are Alembic revisions under `backend/alembic/versions`; the API
applies them on startup, and the DB-lane rebuilds the schema via `alembic upgrade head`, so a broken
migration chain fails the tests.