找不到模块'socket.io/node_modules/redis'

该socket.io的package.json不显示在Redis的依赖关系：

  "dependencies": {    "engine.io": "Automattic/engine.io#15afd3",    "socket.io-parser": "2.2.1",    "socket.io-client": "Automattic/socket.io-client#05c9632",    "socket.io-adapter": "0.2.0",    "has-binary-data": "0.1.3",    "debug": "0.7.4"  }

无论哪种方式，都无需直接依赖于另一个库的依赖项。如果需要

redis

package.json

npm install redis --save

并要求像：

var redis = require('redis');