bluebird 流程控制? - CNode技术社区

昨天看了这个 bluebird 多层嵌套该如何优化。 地址 然后前天正好自己学习promise得时候先这么写了

checkMeetingPath = (meetingPath)->
 console.log('s1')
 return fs.existsAsync(meetingPath)
 .then (exists)->
 console.log('s2')
 return fs.mkdirAsync(meetingPath)
 .catch (exists)->
 console.log('s8')
 return fs.statAsync(meetingPath)
 .then (stats)->
 console.log('s5')
 if stats.isDirectory()
 console.log('s6')
 return Promise.resolve() 
 else
 console.log('s7')
 return fs.unlinkAsync(meetingPath)
 .then ()->
 console.log('s3')
 return fs.mkdirAsync(meetingPath)

昨天看了那个之后做了一点优化 如下:

checkMeetingPath = (meetingPath)->
 notExists = (exists)->
 console.log('s2')
 return fs.mkdirAsync(meetingPath)
 isExists = (exists)->
 console.log('s8')
 return fs.statAsync(meetingPath)
 .then isDirectory
 isDirectory = (stats)->
 console.log('s5')
 if stats.isDirectory()
 console.log('s6')
 return Promise.resolve() 
 # return Promise.reject('dd') 
 else
 console.log('s7')
 return fs.unlinkAsync(meetingPath)
 .then notExists
 
 console.log('s1')
 return fs.existsAsync(meetingPath)
 .then notExists
 .catch isExists

感觉这样优化之后已经舒服了很多了。。不知道哪里可以更加舒服一点, 比如每个return得promise我加得这个then如何更加优雅什么得。

var fs = require("fs");
var Promise = require('bluebird');
Promise.promisifyAll(fs);
var path = "aaa";
function notDirectory(path){
 return(
 fs.unlinkAsync(path)
 .then(function(){
 return fs.mkdirAsync(path)
 })
 
 )
}
function fileExist (path){
 return( 
 fs.statAsync(path)
 .then(function(stats){
 return stats.isDirectory(path)
 })
 .then(function(isDirectory){ 
 if (!isDirectory){
 return notDirectory(path)
 } 
 })
 ) 
}
fs.existsAsync(path)
 .then(function(){ //不存在 
 return fs.mkdirAsync(path);
 },function(){ //存在
 return fileExist(path)
 })
 .catch(function(err){
 console.log(err)
 })