如何在这种情况下进行类型检查？第一:不可分配。然后，键入missing

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

interface Employee {
  name: string;
  employeeId: number;
}

function process(person: Person) {
  // ...
}

const employee: Employee = { name: "John", employeeId: 123 };
process(employee); // 错误：类型“Employee”不能分配给类型“Person”

const employee: Employee = { name: "John", employeeId: 123, age: 30 };

process(employee as unknown as Person); // 不推荐，因为这可能导致运行时错误

type PersonOrEmployee = Person | Employee;

function process(personOrEmployee: PersonOrEmployee) {
  // ...
}

process(employee); // 正确

function isPerson(obj: any): obj is Person {
  return obj && typeof obj.name === "string" && typeof obj.age === "number";
}

function process(personOrEmployee: Person | Employee) {
  if (isPerson(personOrEmployee)) {
    // ...
  } else {
    // ...
  }
}

process(employee); // 正确

interface Person {
  name: string;
  age?: number; // 将 age 设置为可选属性
}

const employee: Employee = { name: "John", employeeId: 123 };
process(employee); // 正确