How can I know if a function has been called or not?

Question

I'm making a small reusable module for my use. and stopped on a point in my code which is, how can I make sure that the consumer of my module has called a function I provided to him or not in one of the methods of my module?

Basically, the API of the module looks like the forEach method, where my module passes internally arguments just like how forEach works

myModule.myMethod(callbackFunc, z)

myModule internally calls your callbackFunc with the following arguments: anotherFunc , x , y

Example usage:

myModule.myMethod((anotherFunc, x, y) => {
    if (x == true) anotherFunc()
}, z)

How can I know that the consumer of the myMethod has called passed_function or not?

Answer 1

Assuming anotherFunc is something you create internally, you can write it so that it updates a boolean, and then later you can check that boolean. For example:

function myMethod(callback, z) {
  let hasBeenCalled = false;
  const anotherFunc = () => {
    hasBeenCalled = true;
    // ...
  }

  callback(anotherFunc, 'hello', 'world');

  if (hasBeenCalled) {
    console.log('they called it!');
  }
}