next.js/examples/with-firebase-hosting/firebase.json

{
  "hosting": {
    "public": "dist/public",
    "rewrites": [
      {
        "source": "**/**",
        "function": "next"
      }
    ],
    "predeploy": "yarn build-public"
  },
  "functions": {
    "source": "dist/functions",
    "predeploy":
      "yarn build-funcs && yarn build-app && yarn copy-deps && yarn install-deps"
  }
}