functionsArguments.js

function getArgs(func) {
  // First match everything inside the function argument parens.
  var args = func.toString().match(/function\s.*?\(([^)]*)\)/)[1];
 
  // Split the arguments string into an array comma delimited.
  return args.split(',').map(function(arg) {
    // Ensure no inline comments are parsed and trim the whitespace.
    return arg.replace(/\/\*.*\*\//, '').trim();
  }).filter(function(arg) {
    // Ensure no undefined values are added.
    return arg;
  });
}

/*
So given the function above and a sample function, here's how it would work:
*/

function myCustomFn(arg1, arg2,arg3) {
  
}

console.log(getArgs(myCustomFn)); // ["arg1", "arg2", "arg3"]