在区分的Union上实现与另一个接口的成员的接口

// 定义联合类型
type MyUnion = {
  type: "A";
  data: string;
} | {
  type: "B";
  data: number;
};

// 定义接口
interface MyInterface {
  methodA(): void;
  methodB(): void;
}

// 在区分的Union上实现与另一个接口的成员的接口
function implementInterface(obj: MyUnion): MyInterface {
  if (obj.type === "A") {
    return {
      methodA: () => {
        console.log("Method A implementation");
      },
      methodB: () => {
        console.log("Default implementation for Method B");
      }
    };
  } else if (obj.type === "B") {
    return {
      methodA: () => {
        console.log("Default implementation for Method A");
      },
      methodB: () => {
        console.log("Method B implementation");
      }
    };
  }
}

// 使用示例
const objA: MyUnion = {
  type: "A",
  data: "Hello"
};

const objB: MyUnion = {
  type: "B",
  data: 123
};

const implementedA = implementInterface(objA);
const implementedB = implementInterface(objB);

implementedA.methodA();  // 输出: Method A implementation
implementedA.methodB();  // 输出: Default implementation for Method B

implementedB.methodA();  // 输出: Default implementation for Method A
implementedB.methodB();  // 输出: Method B implementation