function process1() {
  setTimeout(function() {
   var process1Result = 1;
   next(null, process1Result)
  },10)
}
function process2(data) {
  setTimeout(function() {
  	if (data === 1) var process2Result = 2;
    next(null, process2Result)
  })
}
function process3(data) {
  console.log(data);
}

var taskList = [
  process1,
  process2,
  process3
]
next(err, result) {
  if (err) throw err;
  
  var current = taskList.shift();
  
  current && current(result);
}
next();