firebase.json

{
  "firestore": {
    "rules": "firestore.rules",
    "indexes": "firestore.indexes.json"
  },
  "functions": {
    "predeploy": [
      "npm --prefix \"$RESOURCE_DIR\" run lint",
      "npm --prefix \"$RESOURCE_DIR\" run build"
    ],
    "source": "functions"
  },
  "hosting": {
    "public": "build",
    "ignore": [
      "firebase.json",
      "**/.*",
      "**/node_modules/**"
    ],
    "rewrites": [
      {
        "source": "**",
        "destination": "/index.html"
      }
    ],
    "headers": [
      {
        "source": "**/*.@(jpg|jpeg|gif|png|webp)",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "max-age=31536000"
          }
        ]
      }
    ]
  },
  "storage": {
    "rules": "storage.rules"
  },
  "emulators": {
    "functions": {
      "port": 5001
    },
    "firestore": {
      "port": 8080
    },
    "hosting": {
      "port": 5000
    },
    "ui": {
      "enabled": true
    },
    "pubsub": {
      "port": 8085
    }
  }
}