How to call library function as custom function from spreadsheet formula?

Question

This might be the same root cause as in How to call a library function from a spreadsheet drop-down menu generated by the same library, but I still wanted to throw it out

Answer 1

The solution is to create a function on you Google Apps Script project that calls the library function

/**
 * Description of what your function does
 *  
 * @customfunction
 */
function ReturnParam(theParameter){
  return myLib.ReturnParam(theParameter);
}

Then you could call it from your spreadsheet as a custom function

=ReturnParam(4)