node异步i/o 快速promisify

fs异步

//bluebird的promisify
https://www.cnblogs.com/winyh/p/6676630.html

var Promise = require("bluebird");
var fs = Promise.promisifyAll(require("fs"));

fs.readFileAsync("myfile.json").then(JSON.parse).then(function (json) {
    console.log("Successful json");
}).catch(SyntaxError, function (e) {
    console.error("file contains invalid json");
}).catch(Promise.OperationalError, function (e) {
    console.error("unable to read file, because: ", e.message);
});

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var Promise = require("bluebird");

UserSchema = new Schema({
  username: String,
  password: String,
  created_at: {
    type: Date,
    "default": Date.now
  }
});

var User = mongoose.model('User', UserSchema);

Promise.promisifyAll(User);
Promise.promisifyAll(User.prototype);

//使用
User.findAsync({username: username}).then(function(data) {
   ...
}).catch(function(err) {
   ...
});

开源项目里的promise
ioredis
mongoose && mongoskin

redis.get('foo').then(function (result) {
  console.log(result);
});

fs模块promise可以使用fs-extra，基础上又扩展了方法
https://github.com/jprichardson/node-fs-extra
https://www.xiejiahe.com/blog/detail/5b52fca1df53a14006035e1e