Comment by tonyle

I'm not sure when promises came to the javascript, but it seems weird that people would settle with callback hell for so long without even attempting to refactoring it.

I mean if I didn't have the option of using promises, I would have probably written something like this.

function handler(callback){

  var state={};

  function logic(step,err,data){  
    if(!step){
      connectToDb("somedatabase",logic.bind(state,1))
    }
    
    if(step==1){
      if(err) callback("error1")
      state.dbInstance=data
      state.dbInstance.query("someQuery",logic.bind(state,2))
    }
    
    if(step==2){
      if(err) callback("error2")
      csvExporter(data,logic.bind(state,3))
    }

    if(step==3){
      if(err) callback("error3")
      callback(data)
    }
  }
  logic()
}