how to check what function of js just fired on button click in html code example

Example 1: on load hit click event js

window.onload=function(){
        document.querySelector("body").click();
    };

Example 2: How to make a function run only after 2 events has triggered js

const promise1 = Promise.resolve(3);
const promise2 = 42;
const promise3 = new Promise(function(resolve, reject) {
  setTimeout(resolve, 100, 'foo');
});

Promise.all([promise1, promise2, promise3]).then(function(values) {
  console.log(values);
});
// expected output: Array [3, 42, "foo"]