Instantiating child class from a static method in base class, using TypeScript

Question

Being new to TypeScript, what is the best method to implement a static factory in a base class that instantiates the child class type. For instance, consider a findAl

Answer 1

To answer my own question, this turns out to be a well known issue in TypeScript. The Github issue Polymorphic this for static methods has a long discussion. The solution is as follows:

export type StaticThis = { new (): T };

export class Base {
    static create(this: StaticThis) {
        const that = new this();
        return that;
    }
    baseMethod() { }
}

export class Derived extends Base {
    derivedMethod() { }
}

// works
Base.create().baseMethod();
Derived.create().baseMethod();
// works too
Derived.create().derivedMethod();
// does not work (normal)
Base.create().derivedMethod();