Question

使用socket.io和node.js建立websocket连接时遇到错误。这是我的环境：

操作系统：Windows 7
节点：6.9.2
NPM：4.0.5
包裹：
- ＆＃34;表达＆＃34;：＆＃34; ^ 4.14.0＆＃34;
- ＆＃34; socket.io＆＃34;：＆＃34; 1.7.1＆＃34;
- ＆＃34; socket.io-client＆＃34;：＆＃34; 1.7.1＆＃34;
- ＆＃34; ws＆＃34;：＆＃34; 1.1.1＆＃34;

尝试连接websocket时会引发以下错误：

TypeError: Cannot read property 'on' of undefined
    at PerMessageDeflate.decompress (C:\ng-project\node_modules\ws\lib\PerMessageDeflate.js:242:37)
    at Receiver.applyExtensions (C:\ng-project\node_modules\ws\lib\Receiver.js:362:54)
    at C:\ng-project\node_modules\ws\lib\Receiver.js:508:14
    at Receiver.flush (C:\ng-project\node_modules\ws\lib\Receiver.js:347:3)
    at Receiver.opcodes.1.finish (C:\ng-project\node_modules\ws\lib\Receiver.js:541:12)
    at Receiver.expectHandler (C:\ng-project\node_modules\ws\lib\Receiver.js:493:33)
    at Receiver.add (C:\ng-project\node_modules\ws\lib\Receiver.js:103:24)
    at Socket.realHandler (C:\ng-project\node_modules\ws\lib\WebSocket.js:825:20)
    at ZoneDelegate.invokeTask (C:\ng-project\node_modules\zone.js\dist\zone-node.js:265:35)
    at Zone.runTask (C:\ng-project\node_modules\zone.js\dist\zone-node.js:154:47)
    at Socket.ZoneTask.invoke (C:\ng-project\node_modules\zone.js\dist\zone-node.js:335:33)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)
    at readableAddChunk (_stream_readable.js:177:18)
    at Socket.Readable.push (_stream_readable.js:135:10)
    at TCP.onread (net.js:542:20)

查看ws模块，我可以看到抛出错误的代码行：

this._inflate.on('error', onError).on('data', onData);

_inflate是由前面几行InflateRaw创建的zlib zlib.createInflateRaw({...})实例。问题是InflateRaw#on函数在我的环境中返回undefined。

我已经尝试安装其他版本的Node来解决这个问题而没有任何运气...改变ws包对我来说不是一个可接受的解决方法。

编辑1： 添加引发错误的源代码。

io.on('connection', (socket) => {
  // Listen for verification subscription requests
  log.debug("Established socket connection " + socket.id);
  socket.on('verify subscribe', (msg) => {
    log.debug("Recieved 'verify subscribe' message: " + JSON.stringify(msg));
    // Do stuff....
  });
});

此代码在错误之前输出以下日志消息：

[2016-12-30T19:08:09.219Z] DEBUG: Established socket connection -g9oZM6pEqpFyU_BAAAA
[2016-12-30T19:08:09.275Z] DEBUG: Recieved 'verify subscribe' message: {"token":"short-ish.token","authorization":"long.auth-token"}

Answer 1

发现此问题是zone.js的错误，并已在更高版本（＆gt; 0.7.0）中修复。这个问题在GitHub上跟踪：angular/zone.js#508。

Answer 2

您尚未设置io。确保你已经完成了

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);

来自文档聊天示例 - http://socket.io/get-started/chat/

如果您未设置io，则会undefined。

另见：http://socket.io/docs/#

var app = require('http').createServer(handler)
var io = require('socket.io')(app);

Node.js＆amp; Socket.io - 无法读取＆＃39; on＆＃39;未定义的

2 个答案: