将Node.js HTTP服务器对象传递给Socket.IO时，“对象不是函数”

Question

This was working a few months ago when I was creating an HTTPS server, but I switched to http (not sure this switch is directly related, just mentioning it in case) today when revisiting this application, where I create a server and pass it to socket.io:

init.js

var server      = require(dirPath + "/custom_modules/server").serve(80); 
var socket      = require(dirPath + "/custom_modules/socket").socket(server);

It is important that I pass the server to socket.io (I know there are alternate ways of initializing the socket) this way because that's how it has to be done in order to encrypt the websocket connection when I switch back to serving HTTPS later.

So my server module:

//serve files
module.exports.serve = function(port) {
    //var server = https.createServer(options, function(req, res) { // SSL Disabled
    var server = http.createServer(function(req, res) { 

        // Parse & process URL
        var reqInfo = url.parse(req.url, true, true), path = reqInfo.pathname;

        // Quickly handle preloaded requests
        if (preloaded[path])
            preloadReqHandler(req, res, preloaded[path], path);

        // Handle general requests
        else
            generalReqHandler(req, res, reqInfo);
    }).listen(port);
    return server; //this should be returning an http server object for socket.io
};

and my socket module:

module.exports.socket = function(server) {

    //create socket
    var socket = require(dirPath + '/node_modules/socket.io')(server);
    //                                                       ^ error

    // .. snip ..

    //handle client connection
    socket.on("connection", function(client) {
        // .. snip ..
    });
};

and my error:

 /home/ec2-user/Sales_Freak/server/custom_modules/socket.js:17 var socket = require(dirPath + '/node_modules/socket.io')(server); ^ TypeError: object is not a function at Object.module.exports.socket (/home/ec2-user/Sales_Freak/server/custom_modules/socket.js:17:59) at Object.<anonymous> (/home/ec2-user/Sales_Freak/server/init.js:16:59) 

Assume all of the necessary Node.JS modules are required properly above. What silly mistake am I making today?

Answer 1

The exported module is not a function, refer to your previous statement:

var socket      = require(dirPath + "/custom_modules/socket").socket(server);

And compare that to your current statement:

var socket = require(dirPath + '/node_modules/socket.io')(server);

I think you meant to do this instead.

var socket = require(dirPath + '/node_modules/socket.io').socket(server);

Answer 2

This might or might not be helpful to others, but my problem was that I changed the directory of my Node.js server files and socket.io wasn't installed in the new location.

The module was there in node_modules but not installed. I'm actually not sure how installation works with npm modules, but the module existed and therefore didnt throw an error saying it didnt exist, but did not act like it was really there until I did npm install socket.io

If you get this error in this situation, you forgot install socket.io.