firebase.json

{
  "database": {
    "rules": "database.rules.json"
  },
  "firestore": {
    "rules": "firestore.rules",
    "indexes": "firestore.indexes.json"
  },
  "hosting": {
    "public": "public",
    "ignore": [
      "firebase.json",
      "**/.*",
      "**/node_modules/**",
      "index.html"
    ],
    "rewrites":  [{
      "source": "/**",
      "function": "app"
    }]
  },
  "storage": {
    "rules": "storage.rules"
  },
  "remoteconfig": {},
  "functions": {
    "predeploy": [
      "npm --prefix \"$RESOURCE_DIR\" run lint"
    ],
    "source": "functions"
  },
  "emulators": {
    "auth": {
      "port": 9099
    },
    "functions": {
      "port": 5001
    },
    "firestore": {
      "port": 8081
    },
    "database": {
      "port": 9009
    },
    "hosting": {
      "port": 5000
    },
    "pubsub": {
      "port": 8085
    },
    "storage": {
      "port": 9199
    },
    "ui": {
      "enabled": true
    }
  }
}