How to add and declare new property to class using decorator in typescript (angular)

Question

I'm trying to add new property to class using decorator. Here is my code

function classDecorator<T extends {new(...args: any[]): {}}>(constructor: T) {
    constructor.prototype.newProperty = 'some value';
}


@classDecorator
class MyClass {
  property1: string = 'value1';
  property2: string = 'value1';
}
const obj = new MyClass();

console.log(obj);
console.log(obj.property1);
console.log(obj.property2);
console.log(obj.newProperty); //  error TS2551: Property 'newProperty' does not exist on type 'MyClass'

Is there any way to make angular to understand that MyClass also have newProperty ? Can I do it with .d.ts file?

Answer 1

this post resolve your problem:

How to add a new property to a class using class decorator?