如何在Typescript中深度扁平化界面？

type FlattenObject<T> = T extends object
  ? {
      [K in keyof T]: T[K] extends object ? FlattenObject<T[K]> : T[K];
    }
  : T;

function flattenObject<T>(obj: T): FlattenObject<T> {
  const result = {} as FlattenObject<T>;

  function flatten(obj: any, prefix: string = "") {
    for (const key in obj) {
      if (obj.hasOwnProperty(key)) {
        const value = obj[key];
        const newKey = prefix ? `${prefix}.${key}` : key;

        if (typeof value === "object" && value !== null) {
          flatten(value, newKey);
        } else {
          result[newKey] = value;
        }
      }
    }
  }

  flatten(obj);
  return result;
}

interface Person {
  name: string;
  age: number;
  address: {
    street: string;
    city: string;
  };
}

const person: Person = {
  name: "Alice",
  age: 30,
  address: {
    street: "123 Street",
    city: "City",
  },
};

const flattened = flattenObject(person);
console.log(flattened);