{
  // Processes spawned by `per-env` inherit environment-specific
  // variables, if defined.
  "per-env": {
    "production": {
      "DOCKER_USER": "my",
      "DOCKER_REPO": "project"
    }
  },
  "scripts": {
    // If NODE_ENV is missing, defaults to "development".
    "build": "per-env",

    "build:development": "webpack -d --watch",
    "build:staging": "webpack -p",
    "build:production": "webpack -p",

    // Deployment won't work unless NODE_ENV=production is explicitly set.
    "deploy": "per-env",

    "predeploy:production": "docker build -t ${DOCKER_USER}/${DOCKER_PROJECT} .",
    "deploy:production": "docker push ${DOCKER_USER}/${DOCKER_PROJECT}",

    // "npm start" is _the_ command to start the server across all environments.
    "start": "per-env",

    "start:development": "npm run build:development",

    "prestart:production": "npm run build",
    "start:production": "start-cluster build/server/server.js",

    "prestart:staging": "npm run build",
    "start:staging": "start-cluster build/server/server.js",

    // Explicitly set NODE_ENV, which is helpful in CI.
    "test": "NODE_ENV=test per-env",

    "test:test": "mocha"
  }
}