javascript - Access to XMLHttpRequest from origin has been blocked by CORS policy. CORS issue with hosting React chat app

Question

I'm having some issues deploying my web socket app online. I've used Heroku to host the server and Netlify for the client. I'm getting the below error when I try sending a chat.

Screenshot of error

Here is my server code:

const express = require("express");
const http = require("http");
const app = express();
const server = http.createServer(app);
// const socket = require("socket.io");
const io = socket(server);
const cors = require("cors");
require("dotenv").config();
app.use(cors());

const io = require("socket.io")(httpServer, {
    cors: {
      origin: "https://webchat-socketio.netlify.app/",
      methods: ["GET", "POST"]
    }
  });


const PORT = 7777;
io.on("connection", socket => {
    socket.emit("your id", socket.id);
    socket.on("send message", body => {
        io.emit("message", body)
    })
})


server.listen(process.env.PORT || PORT, () => console.log("server is running online"));

Answer 1

等待大神答复