ttrpg-initiative-tracker/docs/DEVELOPMENT.md

# Development

TTRPG Initiative Tracker — fork with self-hosted backend. Monorepo via npm workspaces.

## Prerequisites

- Node.js 22+
- npm 10+

## Layout

```
/
  package.json          # workspaces root
  src/                  # React frontend (CRA, existing)
    App.js              # ~2935 lines, Firebase direct (M2 abstracts this)
  server/               # Backend: Express + ws + better-sqlite3
    index.js            # REST + WS bootstrap
    db.js               # SQLite schema, row mappers
    handlers.js         # action -> shared turn fn -> tx persist -> broadcast
    server.test.js      # integration tests
  shared/               # Pure logic, no I/O (client + server + tests import)
    turn.js             # turn-order state machine
    turn.characterization.test.js
  docs/
    REWORK_PLAN.md      # milestone plan
    DEVELOPMENT.md      # this file
```

## Setup

```bash
git clone git@github.com:keen99/ttrpg-initiative-tracker.git
cd ttrpg-initiative-tracker
npm install
```

## Run

### Frontend (dev server)

```bash
npm start                 # http://localhost:3000
```

Still uses Firebase by default. Set `REACT_APP_FIREBASE_*` in `.env.local` (copy `env.example`).

### Backend (dev)

```bash
npm run server:dev        # :4001, db: server/data/tracker.sqlite
# or direct with env:
DB_PATH=/tmp/tracker.sqlite PORT=4001 node server/index.js
```

Smoke check:
```bash
curl http://127.0.0.1:4001/health   # -> {"ok":true}
```

Frontend not yet wired to backend — that is M2 (storage adapter + WS client).

## Test

Three commands:

```bash
npm run test:all          # runs shared/ + server/ suites in sequence
npm run shared:test       # turn logic only (shared/ folder)
npm run server:test       # backend REST + combat flow (server/ folder)
```

What each runs:

| Suite | What | Count |
|---|---|---|
| `shared/*.test.js` | turn FSM, pure functions | 39 |
| `server/*.test.js` | REST + combat flow, in-memory db | 7 |

Server tests use `--forceExit` (open WS handles). Tests spin server on random port, in-memory sqlite, tear down per test.

### Local pipeline (pre-push hook)

Private repo = no free GitHub Actions. Tests run locally via git hook.

`.githooks/pre-push` runs `npm run test:all` before every push.

Enable on clone (do once):
```bash
git config core.hooksPath .githooks
```

Already configured on this checkout. Skip with:
```bash
git push --no-verify
```

Future: when repo goes public, free GH Actions viable. Then add `.github/workflows/ci.yml`.

## Build

```bash
npm run build             # CRA production build -> build/
```

Docker build (existing, frontend-only):
```bash
docker build -t ttrpg-initiative-tracker .
docker run -p 8080:80 --rm ttrpg-initiative-tracker
```

Full-stack docker-compose arrives in M5.

## Backend architecture

Server-authoritative. Kills client-side last-write-wins races (root cause of skip bug).

```
Client (browser)                  Server
  |                                 |
  |-- POST /api/.../nextTurn ----->|  action
  |                                 |  store.nextTurn():
  |                                 |    shared.nextTurn(enc) -> patch
  |                                 |    db tx: apply patch
  |                                 |    addLog
  |                                 |    broadcast(change)
  |<---- WS {change} --------------|  push to all subscribers
  |                                 |
  Display / tablet                 |
  |<---- WS {change} --------------|  same push
```

- **SQLite** owns truth. Single writer (server). WAL mode.
- **shared/turn.js** = pure logic, ported verbatim from `App.js`. Bugs preserved for M3 characterization, fixed in M4.
- **WS** = real-time push (replaces Firebase `onSnapshot`). Client subscribes to a key (`'campaigns'`, `'encounter:id'`, `'activeDisplay'`...), server pushes on change.
- **Actions not results.** Client sends "do X", server computes X, persists, broadcasts. No client-side state mutation.

## Storage backend choice

Browser sandbox cannot touch filesystem. Cross-device (DM + tablet + player view) requires a real backend owning the DB file. SQLite = single file, docker volume, trivial backup. Postgres deferred until public multiuser exposure.

## Status

| Milestone | State |
|---|---|
| 0 repo/branch | ✅ done |
| 1 backend + tests | ✅ done |
| 2 frontend WS adapter | ⬜ next |
| 3 characterization tests | ⬜ |
| 4 skip fix + manual override | ⬜ |
| 5 docker compose | ⬜ |
| 6 undo rework | ⬜ |
| 7 playwright e2e | ⬜ deferred |

See `docs/REWORK_PLAN.md` for full plan.

## Git

- `origin` = `github.com:keen99/ttrpg-initiative-tracker` (this fork)
- `upstream` = `code.draft13.com/robert/ttrpg-initiative-tracker` (friend's Gitea, read-only)
- work branch: `rework-backend` (off `main`)

```bash
git fetch upstream         # pull friend's changes
git merge upstream/main    # rebase our branch onto his
```