firebase.json

{
  "functions": {
    "ignore": ["tests", "*.sh", "*.md", "*.txt", "**/node_modules/**"],
    "predeploy": ["npm --prefix \"$RESOURCE_DIR\" run lint", "npm --prefix \"$RESOURCE_DIR\" run build"]
  },
  "hosting": {
    "public": "dist",
    "ignore": ["firebase.json", "**/.*", "**/node_modules/**"],
    "headers": [
      {
        "source": "**",
        "headers": [
          {
            "key": "Content-Security-Policy",
            "value": "frame-ancestors 'none'"
          },
          { "key": "X-Frame-Options", "value": "deny" },
          { "key": "X-Content-Type-Options", "value": "nosniff" },
          { "key": "X-XSS-Protection", "value": "1; mode=block" },
          { "key": "X-Permitted-Cross-Domain-Policies", "value": "none" },
          { "key": "Referrer-Policy", "value": "no-referrer" }
        ]
      }
    ],
    "rewrites": [
      {
        "source": "/api/**",
        "function": "express_server",
        "region": "asia-northeast1"
      },
      {
        "source": "**",
        "destination": "/index.html"
      }
    ]
  }
}