Async Stacktrace

errortest.js

/*
$ node errortest.js 

/home/pita/Desktop/errortest.js:46
      throw err;
      ^
Async Stacktrace:
    at /home/pita/Desktop/errortest.js:56:9
    at /home/pita/Desktop/errortest.js:66:8
    at /home/pita/Desktop/errortest.js:77:8

Error
    at Timer.callback (/home/pita/Desktop/errortest.js:87:14)
*/


function ERR(err, callback)
{
  if(err != null)
  {
    if(err.stack != null)
    {
      var asyncStackLine = new Error().stack.split("\n")[2];
      var stackParts = err.stack.split("\n");
      
      if(stackParts[0] != "Async Stacktrace:")
      {
        stackParts.unshift("Async Stacktrace:",""); 
      }
      
      stackParts.splice(1,0,asyncStackLine);
      
      err.stack = stackParts.join("\n");
    }
    else
    {
      err = new Error(err);
    }
  
    if(callback != null)
    {
      callback(err);
    }
    else
    {
      throw err;
    }
  }
  
  return err != null;
}

function one()
{
   two(function(err){
     if(ERR(err)) return;  
   
     console.log("two finished");
   });
}

function two(callback)
{
  three(function(err)
  {
    if(ERR(err, callback)) return;  
    
    console.log("three finished");
    callback();
  });
}

function three(callback)
{
  four(function(err)
  {
    if(ERR(err, callback)) return;  
    
    console.log("four finished");
    callback();
  });
}

function four(callback)
{
  setTimeout(function(){
    callback(new Error());
  }, 0);
}

one();