LazyMan.js

function LazyMan(name) {
  return new _LazyMan(name);
}

function _LazyMan(name) {
  var self = this;
  self.name = name;
  self.tasks = [];

  var greeting = function() {
    console.log("Hello this is " + self.name);
    self.next();
  };

  self.tasks.push(greeting);

  setTimeout(function() {
    self.next();
  }, 0);
}

_LazyMan.prototype.next = function() {
  var fn = this.tasks.shift();
  fn && fn();
};

_LazyMan.prototype.eat = function(eatWhat) {
  var self = this;
  var fn = (function(eatWhat) {
    return function() {
      console.log('Eat ' + eatWhat);
      self.next();
    };
  })(eatWhat);

  self.tasks.push(fn);
  return self;
};

_LazyMan.prototype.sleep = function(seconds) {
  var self = this;
  var fn = (function(seconds) {
    setTimeout(function() {
      self.next();
    }, seconds * 1000);
  })(seconds);
  self.tasks.push(fn);
  return self;
};

_LazyMan.prototype.sleepFirst = function(seconds) {
  var self = this;
  var fn = (function(seconds) {
    setTimeout(function() {
      self.next();
    }, seconds * 1000);
  })(seconds);
  self.tasks.unshift(fn);
  return self;
};

LazyMan('Hank')
  .eat('lunch')
  .sleep(1)
  .eat('supper')
  .sleepFirst(2);