Repository Guidelines

Project Structure & Module Organization

src/ holds the React client: index.js bootstraps the app, PickupConfigEditor.js manages form logic, and sibling files (App.js, *.css, *.test.js) live beside their concerns for easy discovery.
public/ contains the static shell served during development; only add files that must be copied verbatim into the build output.
server.js is the Express + MQTT bridge that serves the built client, exposes /api/iobroker/pickup-config, and persists data to config/pickup-config.json.
config/ stores generated runtime state. Keep it writable but untracked so local credentials never leak.
build/ is created by npm run build and shipped by the Express server or Docker image; never edit files here manually.
docker-compose.yml, Dockerfile, and rebuildContainer.sh encapsulate deployment; update them when server ports, env vars, or base images change.

npm install – restore dependencies in package.json.
npm start – launch the CRA dev server on port 3000 with live reload.
npm run build – emit the production bundle into build/; run before node server.js or container builds.
npm test – run React Testing Library suites in watch mode; append -- --watch=false in CI.
node server.js – serve the prebuilt UI, REST API, and MQTT sync using values from .env (e.g., MQTT_BROKER, MQTT_TOPIC, MQTT_USER, MQTT_PASSWORD).
docker-compose up --build – rebuild and start the containerized service, syncing the bundled UI and server.

Use 2-space indentation and Standard/Prettier-compatible formatting; rely on the CRA ESLint config (react-app, react-app/jest) for feedback.
Favor functional React components with PascalCase filenames (PickupConfigEditor.js) and camelCase props/state keys.
Keep config schema fields (e.g., desiredWeekday, onlyNotify) camelCase across client, API payloads, and MQTT messages.
Prefer descriptive folder-local CSS files rather than global selectors; co-locate assets next to their component whenever possible.

React Testing Library + Jest underpin App.test.js; add <Component>.test.js files alongside components to exercise rendering, validation, and MQTT payload shaping.
Initialize helpers inside setupTests.js to keep suites lean.
Aim for meaningful edge cases (blank config, duplicate IDs, toggling onlyNotify). Pull requests should demonstrate passing npm test output or CI logs.

Follow conventional commits (e.g., feat: add mqtt auth fields, fix: debounce config saves) and keep subjects ≤72 characters.
After every change, refresh .commitmessage with the final commit text and ensure it is staged (e.g., git add -f .commitmessage) so tooling can reuse it automatically.
Reference issues or MQTT topics impacted inside the body, and describe user-visible changes plus verification steps.
PRs must include: summary of API/UI changes, screenshots or JSON samples when modifying config shape, notes on new env vars, and confirmation that npm test and npm run build succeed.

Store secrets in .env, not in version control; provide .env.example updates when new variables (ports, credentials) are introduced.
The server writes to config/pickup-config.json; ensure the directory exists and has the correct permissions before deploying or running containers.