astro/packages/create-astro/tsconfigs/tsconfig.strict.json

{
  "compilerOptions": {
    // Enable top-level await, and other modern ESM features.
    "target": "ESNext",
    "module": "ESNext",
    // Enable node-style module resolution, for things like npm package imports.
    "moduleResolution": "node",
    // Enable JSON imports.
    "resolveJsonModule": true,
    // Enable stricter transpilation for better output.
    "isolatedModules": true,
    // Astro will directly run your TypeScript code, no transpilation needed.
    "noEmit": true,
    // Enable strict type checking.
    "strict": true,
    // Error when a value import is only used as a type.
    "importsNotUsedAsValues": "error"
  }
}