How to find the source code in a particular line number in javascript?

I have line numbers for vanilla js files for which i need to find the source code at that particular line and subsequently the parent function.I am using node.js and was wondering if there was a way to extract the source code and possibly know the parent function of that particular line.

function helloworld(){
   var a=5;
   var b=6; //line number 3
}

For the above function i need the function helloworld from only having the line number?

via Anantha Padmanaban