如何在TypeScript中定义通用字段复制函数

function copyFields<T extends object, U extends object>(source: T, target: U): U {
  for (let key in source) {
    if (source.hasOwnProperty(key)) {
      target[key] = source[key];
    }
  }
  return target;
}

interface Person {
  name: string;
  age: number;
}

interface Employee {
  id: number;
  department: string;
}

const person: Person = { name: "John", age: 30 };
const employee: Employee = { id: 1, department: "IT" };

const copiedEmployee = copyFields(person, employee);
console.log(copiedEmployee);