Question

我正试图找出以下代码无法编译的确切原因：

type IEntityName = 'model1' | 'model2' | 'model3'

class Model {
    id: string

    constructor(id: string) {
        this.id = id
    }
}

class ModelChild1 extends Model { }
class ModelChild2 extends Model { }
class ModelChild3 extends Model { }

const MAP = {
    model1: ModelChild1,
    model2: ModelChild2,
    model3: ModelChild3
}

function getModel(entityName: IEntityName) {
    return MAP[entityName]
}

function doSomethingElse<T extends Model>(model: new () => T) {

}

function doSomething(entityName: IEntityName) {
    const model = getModel(entityName)
    doSomethingElse(model)
}

doSomething('model2')

Playground link

我不了解问题，更重要的是，我不了解如何解决。

Answer 1

您缺少构造函数参数类型，应该是：

new (id: string) => T

类型X的参数不能分配给类型Y的参数（尽管有继承）

1 个答案: