firebase.json

{
  "firestore": {
    "rules": "firestore.rules",
    "indexes": "firestore.indexes.json"
  },
  "hosting": {
    "public": "out",
    "ignore": ["firebase.json", "**/.*", "**/node_modules/**"],
    "rewrites": [
      {
        "source": "/robots.txt",
        "destination": "/robots.txt"
      },
      {
        "source": "/sitemap.xml",
        "destination": "/sitemap.xml"
      },
      {
        "source": "**",
        "destination": "/index.html"
      },
      {
        "source": "**/**",
        "destination": "/index.html"
      }
    ],
    "headers": [
      {
        "source": "**/*.@(js|css)",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "max-age=31536000"
          }
        ]
      },
      {
        "source": "**/*.@(jpg|jpeg|gif|png|svg)",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "max-age=31536000"
          }
        ]
      },
      {
        "source": "index.html",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "no-cache"
          }
        ]
      }
    ]
  }
}