Tief verschachtelte Eigenschaftspfad-Auflösung über rekursive Template-Literal-Typen

type Path<T> = T extends object
  ? { [K in keyof T & (string | number)]: K extends string ? `${K}` | `${K}.${Path<T[K]>}` : never }[keyof T & (string | number)]
  : never;
 
type DeepGet<T, P extends string> = P extends `${infer K}.${infer Rest}`
  ? K extends keyof T ? DeepGet<T[K], Rest> : never
  : P extends keyof T ? T[P] : never;
 
interface Configuration {
  database: { connection: { host: string; port: number } };
}
 
function getNestedConfig<T extends object, P extends Path<T>>(obj: T, path: P): DeepGet<T, P> {
  return path.split('.').reduce((acc: any, key) => acc?.[key], obj);
}
 
const config: Configuration = { database: { connection: { host: "localhost", port: 5432 } } };
const port = getNestedConfig(config, "database.connection.port");