打字稿：如何注释类(而不是类实例)的类型？

Question

让我们假设有一个模型类，如：

export abstract class Target {
id!: number;
name!: string;
}
export class Target1 extends Target {
name = 'target1';
id: number;
kind: string;
constructor(id: number, kind: string) {
super();
this.id = id;
this.kind = kind;
}

static getForm(){
return new FormGroup({...});
}
}
export class Target2 extends Target {
name = 'target2';
id: number;
address: string;
constructor(id: number, address: string) {
super();
this.id = id;
this.address = address;
}
static getForm(){
return new FormGroup({...});
}
}
....
export class TargetN extends Target {}
type Measure = {
type: string;
target: any; // Here is what I need to correct the type
}
const measures: Measure[] = [
{ type: 'measure1', target: Target1},
{ type: 'measure2', target: Target2},
...
{ type: 'measureN', target: TargetN},
];

在表单中，我允许用户根据用户选择的measures.type的情况输入address或kind，然后我将创建一个新的target，如下所示：

const inputValue = 'http://localhost:3000';
const selectedType = measures[0].type;
const measure = measures.find(m => m.type === selectedType)!;
const target = new measure.target(1, inputValue);
const form = measure.target.getForm();
console.log(target.kind); // 
...

一切都很好。但让我恼火的是，我不知道如何将正确的类型放在Measure -> target而不是any:

type Measure = {
type: string;
target: any; // ??? 
}

如果我给它一个Target类型，如下所示：

type Measure = {
type: string;
target: Target;
}

然后我会得到错误

Did you mean to use 'new' with this expression?

如果我给它typeof，就像下面这样：

type Measure = {
type: string;
target: typeof Target;
}

然后我会得到错误

Type 'typeof Target1' is not assignable to type 'typeof Target'.

如何用另一种特异性类型替换靶点中的any型？

如果我使用ThisType，它看起来不错

type Measure = {
type: string;
target: ThisType<Target>;
}

但CCD_ 10在CCD_ 11中会抛出错误

Property 'getForm' does not exist on type 'ThisType<Target>'.

我还尝试了Required，如下所示：

type RequiredTarget = Required<typeof Target>;
type Measure = {
type: string;
target: RequiredTarget;
}

但它也不起作用。

我很感激你的帮助。

Answer 1

我会用以下方式来处理这个问题：

type S = string;
type I = number;
interface IY {
type?: string;
target?: S | I;
}
type Y = IY
const U: Y = { type: "U", target: "1" }
const V: Y = { type: "V", target: 2 }
const X: Y = {}