firebase.json

{
  "firestore": {
    "rules": "firestore.rules",
    "indexes": "firestore.indexes.json"
  },
  "functions": {
    "predeploy": [
      "npm --prefix \"$RESOURCE_DIR\" run build"
    ],
    "source": "functions"
  },
  "hosting": {
    "public": "dist",
    "ignore": [
      "firebase.json",
      "**/.*",
      "**/node_modules/**"
    ],
    "rewrites": [
      {
        "source": "**",
        "function": "prerender"
      }
    ],
    "headers": [
      {
        "source": "**",
        "headers": [
          {
            "key": "X-Content-Type-Options",
            "value": "nosniff"
          },
          {
            "key": "X-Frame-Options",
            "value": "sameorigin"
          },
          {
            "key": "X-XSS-Protection",
            "value": "1; mode=block"
          },
          {
            "key": "Referrer-Policy",
            "value": "same-origin"
          }
        ]
      }
    ]
  },
  "storage": {
    "rules": "storage.rules"
  },
  "emulators": {
    "functions": {
      "port": 5001
    },
    "firestore": {
      "port": 8080
    },
    "hosting": {
      "port": 5000
    },
    "pubsub": {
      "port": 8085
    },
    "ui": {
      "enabled": true,
      "port": 4000
    },
    "auth": {
      "port": 9099
    },
    "database": {
      "port": 9000
    },
    "storage": {
      "port": 9199
    }
  },
  "database": {
    "rules": "database.rules.json"
  }
}