Uncaught TypeError: (intermediate value)(…) is not a function

Question

Everything works fine when I wrote the js logic in a closure as a single js file, as:

(function(win){
   //main logic here
   win.expose1 = ....
   win.expos         


        

Answer 1

When I create a root class, whose methods I defined using the arrow functions. When inheriting and overwriting the original function I noticed the same issue.

class C {
  x = () => 1; 
 };
 
class CC extends C {
  x = (foo) =>  super.x() + foo;
};

let add = new CC;
console.log(add.x(4));

this is solved by defining the method of the parent class without arrow functions

class C {
  x() { 
    return 1; 
  }; 
 };
 
class CC extends C {
  x = foo =>  super.x() + foo;
};

let add = new CC;
console.log(add.x(4));