ts 接口类型检查

Question

interface ClockConstructor {
  new (hour: number, minute: number): ClockInterface;
}
interface ClockInterface {
  tick(): void;
}

function createClock(
  ctor: ClockConstructor,
  hour: number,
  minute: number
): ClockInterface {
  return new ctor(hour, minute);
}

class DigitalClock implements ClockInterface {
  constructor(h: number) {}
  tick() {
    console.log("beep beep");
  }
}
class AnalogClock implements ClockInterface {
  constructor(h: number, m: number, s: number) {}
  tick() {
    console.log("tick tock");
  }
}

class CCClock implements ClockInterface {
  constructor(h: number, m: number) {}
  tick() {
    console.log("tick tick");
  }
}

let digital = createClock(DigitalClock, 12, 17); // why not get type check error
let analog = createClock(AnalogClock, 7, 32); // get type check error
let CCyes = createClock(CCClock, 7, 32);

我正在寻找示例并做一些练习。 “DigitalClock”错过了“分钟”参数。为什么“DigitalClock”没有tyoe检查错误。

Answer 1

您需要在您的类之间建立关系，通用将是 go 的方式。

一种解决方案可能如下：

interface ClockInterface<Params> {
    tick(): void
}

// The shared constructor type 
type ConstructorFunction<T> = new (args: T) => ClockInterface<T>;


function createClock<P>(
    ctor: ConstructorFunction<P>,
    params: P,
): ClockInterface<P> {
    return new ctor(params);
}

class DigitalClock implements ClockInterface<{ h: number }> {
    constructor(params: { h: number }) {}
    tick() {
        console.log("beep beep");
    }
}
class AnalogClock implements ClockInterface<{ h: number, m: number, s: number }> {
    constructor(params: { h: number, m: number, s: number }) { }
    tick() {
        console.log("tick tock");
    }
}

class CCClock implements ClockInterface<{ h: number, m: number }> {
    constructor(params: { h: number, m: number }) { }
    tick() {
        console.log("tick tick");
    }
}

let digital = createClock(DigitalClock, { h: 12 }); // why not get type check error
let analog = createClock(AnalogClock, { h: 7, m: 32, s: 2 }); // get type check error
let CCyes = createClock(CCClock, { h: 7, m: 32 });

操场

Answer 2

function printLabel(labelledObj: { label: string; test: string }) {
  console.log(labelledObj.label);
}

let myObj = {label: "Size 10 Object" };
printLabel(myObj);

“myObj”参数会出错。 那么接口验证有什么问题呢？ 如果我错过了什么？