Node.js 应用程序在本地运行，但 heroku 说缺少模块

Question

I made a simple chat application using Node.JS and Socket.IO, everything works fine locally, but when I push it to heroku it gives me an application error, when I check the logs, this is the error:

Error: Cannot find module 'indexof'
    at Function.Module._resolveFilename <module.js:338:15>
    at Function.Module._load <module.js:280:25>
    at Module.require <module.js:364:17>
    at require <module.js:380:17>
    at Object.<anonymous> </app/node_modules/socket.io/node_modules/socket.io-parser/node_modules/emitter/index.js:6:13>
    at Module._compile <module.js:456:26>
    at Object.Module._extensions..js <module.js:474:10>
    at Module.load <module.js:356:32>
    at Functin.Module._load <module.js:312:12>
    at Module.require <module.js:364:17>

So I figured out that indexof is a module that Socket.IO uses, and it is in my node_modules folder, but for some reason either it's not being pushed to heroku or it's just not being recognized. I reinstalled my modules 5-6 times and recreated the app but it's still giving me the same error. My package.json file has 3 dependencies: Express, Socket.IO and Jade

Answer 1

好的，所以在 2 小时后我发现了问题，包含 indexof 模块的多个名为“emitter”的文件夹也有一个 gitignore 文件，该文件使 git 忽略该模块，不知道为什么它甚至在那里，但删除它们解决了问题

Answer 2

就我而言，我不得不向依赖项添加一些模块，因为它们仅在 devdependecies 下，而不是在生产环境中构建

Answer 3

I had the same problem , please read it carefully

These are solutions to socket.io related problems

I hope i will work

1. Ports in your (index.js or server.js) & (index.html and your client.js) port must be different. (refer below code)

=============your index.js file ======================

(port here is 8000)

const express = require("express")
var app = express();
const http = require('http')
var server = http.createServer(app);
  
const port = process.env.PORT || 8000
server.listen(port,()=>
{
    console.log("Listening at port => "+port)
});
var io = require('socket.io')(server, {
    cors: {
      origin: '*',
    }
});

const cors = require("cors")
app.use(cors()) 

=============your client.js file ======================

port here is 8080

const socket = io.connect('https://localhost:8080/')

=============your index.html file ======================

port here is 8080

 <script defer src="https://localhost:8080/socket.io/socket.io.js"> 
 </script>

Remember your "server.js or index.js" port should be different from "client.js" port (Rememeber this is important)

(index.html and your client.js) port must be same

2. You should always use 'http' while working with socket.io (refer above code)

3. U may not included cors as it allows u to have more resourses , without cors heroku prevent some dependencies to not install in heroku (refer above code)

4. Try replacing "io" to "io.connect"

   const socket = io.connect('https://localhost:8080/')

5. Must write tag at the end in the HTML

6. U may forget to add this code which is must in "socket.io"

It is required in your html file

7. delete "node_modules" and "package-lock.json" and write "npm i" in cmd

8. This should be in package.json 's scripts

   "start":"node index.js",

I am not talking about nodemon , use simple node over here

9. May be version is creating a problem , u can avoid it by copying all "devDependencies" to "dependencies" in "package.json" and put "*" in version like this

   "dependencies": {

   "cors": "*",

   "express": "*",

   "nodemon": "*",

   "socket.io": "*"

   },

   "devDependencies": {}