實現一個函數的鏈式調用

實現一個LazyPig，可以按照以下方式調用:
/* LazyPig(“Peggy”)輸出:
Hello，I’m Peggy！

LazyPig("Peggy").sleep(10).eat("dinner")輸出
Hello，I'm Peggy！
//等待10秒..
Wake up after 10
Eat dinner~

LazyPig("Peggy").eat("dinner").eat("supper")輸出
Hello，I'm Peggy！
Eat dinner~
Eat supper~

以此類推。
*/

//最開始：
function LazyPig(name){
	return new Lazy(name)
}
function Lazy(name){
	this.name = name;
	console.log('Hi, 我是' + name)
}
Lazy.prototype = {
	eat: function(smt){
		console.log(this.name + ' is eating ' + smt)
		return this
	},
	sleep: function(time){
		setTimeout(()=>{
			console.log(this.name + ' wake up !')
		}, time * 1000)
		return this;
	}
}
LazyPig('哼哼').eat('dinner').sleep(5)

發現有點不合題意，如果eat在sleep之後調用，也是緊跟着name直接log出來了，應該在sleep 5s之後 跟在sleep之後

function LazyPig(name){
	return new Lazy(name)
}
function Lazy(name){
	this.name = name;
	this.task = [];
	console.log('Hi, 我是' + name)
	let _this = this;
	let fn = (function(){
		return function(){
			_this.next()
		}
	})()
	this.task.push(fn)
	setTimeout(()=>{
		_this.next()
	},0)
}
Lazy.prototype = {
	next: function(){
		var fn = this.task.shift()
		fn && fn()
	},
	sleep: function(time){
		let _this = this;
		let fn = (function(time){
			return function(){
				setTimeout(()=>{
					console.log(_this.name + ' Wake up !')
					_this.next()
				}, time * 1000)
			}
		})(time)
		this.task.push(fn)
		return this;
	},
	eat: function(smt){
		let _this = this;
		let fn = (function(smt){
			return function(){
				console.log(_this.name + ' is eating ' + smt);
				_this.next()
			}
		})(smt)
		this.task.push(fn)
		return this;
	}
}
LazyPig('哼哼').sleep(5).eat('早飯')