TypeScript: self-referencing return type for static methods in inheriting classes

Question

With Polymorphic this in TypeScript 1.7, as I discovered here, we can define a method in a class with a return type of this, and automatically, any classes that

Answer 1

Based on the simplest answer to the GitHub issue, you can use InstanceType<> like this:

class Foo {
    static create(this: T): InstanceType {
        return new this() as InstanceType
    }

    static getAll(this: T): Array> {
        return []
    }
}

class Bar extends Foo { }

const a = Bar.getAll() // typeof a is Bar[]
const b = Bar.create() // typeof b is Bar.

Where I threw in the create function just for illustration, from the linked GitHub example.