TypeScript 泛型创建实例

Question

I'm trying to create a factory for instantiating my classes with generics. Checked out TypeScript docs and it all works perfectly. In short, this works just fine:

class Person {
    firstName = 'John';
    lastName = 'Doe';
}

class Factory {
    create<T>(type: (new () => T)): T {
        return new type();
    }
}

let factory = new Factory();
let person = factory.create(Person);

console.log(JSON.stringify(person));

Now define class Person in directory :

export class Person extends BasePerson {
    firstName = 'John';
    lastName = 'Doe';
}

And when I import Person from other package:

import { Person } from "./directory"

class Factory {
    create<T>(type: (new () => T)): T {
        return new type();
    }
}

let factory = new Factory();
let person = factory.create(Person);

I get error: Argument of type 'typeof Person' is not assignable to parameter of type 'new () => Person'

How can I get a value of Person instead of typeof Person ?

Using TypeScript 3.7.2 and Node v10.13.0.

Answer 1

Could you try this for me please?

import { Person } from "./directory"

class Factory {
    create<T>(type: (new () => T)): T {
        return new type();
    }
}

let factory = new Factory();
let person = factory.create(new Person);

Answer 2

Actual problem here was a parent class of Person -> BasePerson . BasePerson expected an argument in its constructor, so when I tried to call factory.create(Person) , Person actually was an typeof because it expected an argument for base class constructor. Problem was solved by deleting the constructor in base class and injecting a property via ioc container, in my case Inversify .