extend a javascript class

I want to extend the 'Promise' class to follow the following structure: export default class extends Promise{ constructor(executor){ run(()=>{ //function run(fn){return fn();} super(); //executing the super constructor must be inside run() //don't create a new instance, i.e this.promise=new Promise(..) // method implementation and other methods (except wait()) is not required, only the structure withoute TypeScript errors }); return this; } then(...args){ run(()=>{ //some adjustments for args return [login to view URL](...args) }); } wait(seconds){ //wait some time return this } } //just executes fn() and returns its value function run(fn){return fn();}