Extending builtin objects in TypeScript on Netbeans with plugin

Question

I am trying to transcript existing JavaScript code into TypeScript and ran into a problem with extending builtin objects by Object.defineProperty, e.g. String.prototype.

Object.defineProperty(String.prototype, 'testFunc',
{ value: function():string {return 'test';}
});

var s1:string = 'abc'.testFunc();             // Property 'testFunc' does not exist on type 'string'
var s2:string = String.prototype.testFunc();  // Property 'testFunc' does not exist on type 'String'


Object.defineProperty(Object, 'testFunc',
{ value: function():string {return 'test';}
});

var s:string = Object.testFunc();             // Property 'testFunc' does not exist on type 'ObjectConstructor'

It gets properly translated into JavaScript, however, Netbeans 8.1 with a TypeScript plugin claims the errors listed as comments above.

All of my confused experiments with declare and interface did not match any proper syntax. I have no idea how to get it work.

How can I extend builtin objects in TypeScript and make the IDE accepting it?

Answer 1

After 1001 try'n'errors I've figured out a working solution. By now it seems to do what I want.

interface String { strFunc:Function; }

Object.defineProperty(String.prototype, 'strFunc',
{ value: function():string {return 'test';}
});

var s1:string = 'abc'.strFunc();
var s2:string = String.prototype.strFunc();


interface ObjectConstructor { objFunc:Function; }

Object.defineProperty(Object, 'objFunc',
{ value: function():string {return 'test';}
});

var s:string = Object.objFunc();

// objFunc should not work on strings:
var s:string = 'a string instance'.objFunc(); // Property 'testFunc' does not exist on type 'string'