Type X is not a 'constructor function type' (TS2507)

typescript typescript1.6
Bruno Grieder picture Bruno Grieder · Nov 6, 2015 · Viewed 12k times · Source

While designing a definition file, I came across this error (TS2507).

How can I specify a type to be a 'constructor function type' ?

Answer

JKillian picture JKillian · Nov 6, 2015

If you are defining an interface, you can declare that it is a constructor like such:

interface SomeInterface {
  new(someParam: any): SomeInterface
}

This is useful when you are defining typings for already existing JS libraries. See this SO answer for more details.

Related questions

How to structure utility class

I have several utility functions. What is the best way to package these up, and then import them? This is what I am trying to do: import * as util from './util' export class myClass{ constructor() { util.doSomething("test"); } } Then …

Read More
NodeJS EventEmitter with TypeScript class

Is it possible to use NodeJS' events.EventEmitter with a TypeScript class? If yes, how? I've tried countless variations in the last hours to get this working, so I won't list any of them. What I basically want to do: …

Read More
Anonymous/inline interface implementation in TypeScript

I've just started with TypeScript and I'm trying to understand why the following inline object definition isn't considered valid. I have a collection of objects - their type is irrelevant (to me), but they implement the interface so that when …

Read More