firebase.json

{
  "hosting": {
    "public": "build",
    "ignore": ["firebase.json", "**/.*", "**/node_modules/**"],
    "rewrites": [
      {
        "source": "/api",
        "function": "api"
      },
      {
        "source": "/test",
        "function": "test"
      },
      {
        "source": "/getAnalytics",
        "function": "getAnalytics"
      },
      {
        "source": "/getAnalyticsReport",
        "function": "getAnalyticsReport"
      },
      {
        "source": "**",
        "destination": "/index.html",
        "headers": [
          {
            "key": "Access-Control-Allow-Origin",
            "value": "*"
          }
        ]
      }
    ]
  },
  "functions": {
    "predeploy": [
      "npm --prefix \"$RESOURCE_DIR\" install",
      "npm --prefix \"$RESOURCE_DIR\" run lint",
      "npm --prefix \"$RESOURCE_DIR\" run build"
    ]
  }
}