Problem with asynchronous code in class ES6

@Konkery, did you even try? where is your 'correct' code and the console output? ...because it just works...

Here the fixed code (w/ B extending A) with the two presented options for tackling the correct context:

// someES6Test01.js
//
class A {
    constructor(x, y) { // class field...
      this.x = x;
      this.y = y;
    }
    asyncFuncA() { // code...
        console.log("A.asyncFuncA()");
    }
    run() { // call async code
        var _this = this;
        setInterval(() => {
            _this.asyncFuncA();
        }, 1000);
    }
}
class B extends A {
    constructor(x, y){
        super(x,y);
    }
    AsyncFuncB() { //code...
        console.log("B.asyncFuncB()");
    }
    run() { // call async code
        super.run();
        setInterval((_) => { // Todo...
            _.AsyncFuncB();
        }, 2000, this);
    }
}
/**********************************************/
let x = 1; let y = 2;
let ob = new B(x, y);

function onInit() {
  ob.run();
}

setTimeout(onInit,500); // while dev'n```

And related console output (PICO w/ Espruino 2v01):

>
 ____                 _
|  __|___ ___ ___ _ _|_|___ ___
|  __|_ -| . |  _| | | |   | . |
|____|___|  _|_| |___|_|_|_|___|
         |_| espruino.com
 2v01 (c) 2018 G.Williams
>
A.asyncFuncA()
A.asyncFuncA()
B.asyncFuncB()
A.asyncFuncA()
A.asyncFuncA()
B.asyncFuncB()
A.asyncFuncA()
A.asyncFuncA()
B.asyncFuncB()
A.asyncFuncA()
>reset() // entered to stop running intervals
=undefined
> 

Since there were other bugs in the code - missing parent class reference extends B- , I'm suspicious about even needing the work around - with correct code... I try now the code with out the tackling of the this context, but with fixed class B... (and some more identifiable output in the console):

AND IT WORKS TOO - I assume now that you ran a different code than what you pug in post #1,... and that code is buggy on some other terms...

// someES6Test01b.js
//
class A {
    constructor(x, y) { // class field...
      this.x = x;
      this.y = y;
    }
    asyncFuncA() { // code...
        console.log("A.asyncFuncA()",getTime() % 100);
    }
    run() {
        //call async code
        setInterval(() => {
            this.asyncFuncA();
        }, 1000);
    }
}
class B extends A {
    constructor(x, y) {
        super(x,y);
    }
    asyncFuncB() { // code...
        console.log("B.asyncFuncB()",getTime() % 100);
    }
    run() { // call async code
        super.run();
        setInterval(() => { // Todo...
            this.asyncFuncB();
        }, 2000);
    }
}
/**********************************************/
let x = 1; let y = 2;
let ob = new B(x, y);

function onInit() {
  ob.run();
}

setTimeout(onInit,500); // while dev'n

...and related output:

>
 ____                 _
|  __|___ ___ ___ _ _|_|___ ___
|  __|_ -| . |  _| | | |   | . |
|____|___|  _|_| |___|_|_|_|___|
         |_| espruino.com
 2v01 (c) 2018 G.Williams
>
A.asyncFuncA() 64.51624393463
A.asyncFuncA() 65.51623725891
B.asyncFuncB() 65.51758861541
A.asyncFuncA() 66.51625156402
A.asyncFuncA() 67.51624679565
B.asyncFuncB() 67.51758384704
A.asyncFuncA() 68.51623630523
A.asyncFuncA() 69.51630210876
B.asyncFuncB() 69.51768684387
A.asyncFuncA() 70.51631069183
A.asyncFuncA() 71.51631927490
B.asyncFuncB() 71.51773548126
A.asyncFuncA() 72.51630496978
A.asyncFuncA() 73.51627349853
B.asyncFuncB() 73.51770114898
>reset() // entered to stop running intervals
=undefined

Conclusion: Everything is just fine... @Gordon: 100 pts, @candidate: 0 - GAME OVER