Base Class extended Incorrectly

Question

Hey I am using Deno and extending EventTarget class but I don't want the end user to be able to get functions which exist on EventTarget class like addEventListener,dispatchEvent and removeEventListener. I am doing this right now:

class Test extends EventTarget{
    constructor(){
        super()
    }
    private addEventListener(){}
    private dispatchEvent(){}
    private removeEventListener(){}
}

But I am getting Error:

Class 'Test' incorrectly extends base class 'EventTarget'.
  Property 'addEventListener' is private in type 'Test' but not in type 'EventTarget'

Answer 1

...but I don't want the end user to be able to get functions which exist on EventTarget class like addEventListener,dispatchEvent and removeEventListener...

Then it's not a subclass of EventTarget. A subclass has all the members of its superclass and is an instance of that superclass (see the Liskov Substitution Principle). You should be able to use a subclass instance anywhere a superclass instance is expected.

You'll need to implement a class with the methods you want from EventTarget (perhaps delegated to a private EventTarget instance) rather than subclassing EventTarget.