x-common: &common # shared values
  build: &build-base
    context: .
    dockerfile: Dockerfile
  ports: &ports
    - '3000:3000'
  healthcheck:
    &healthcheck # curl outputs to /dev/null to prevent clutter in logs
    test: ['CMD', 'curl', '-sf', 'http://localhost:3000', '-o', '/dev/null']
    interval: 5s
    timeout: 3s
    retries: 1
    start_period: 3s

services:
  app-dev:
    build:
      <<: *build-base
      target: dev
    volumes:
      - ./src:/app/src # enables hot reload
      - /app/node_modules # keeps installed node_modules
    ports: *ports
    healthcheck: *healthcheck

  app-prod: &app-prod
    labels:
      - 'production'
    build:
      <<: *build-base
      target: prod
    ports: *ports
    healthcheck: *healthcheck

  app-test:
    <<: *app-prod
    environment:
      - NODE_ENV=test # override environment variables
    ports:
      - '3001:3000' # override ports to prevent conflicts while testing
    healthcheck: *healthcheck # uses internal port 3000, not host 3001