socket.io polling request blocked by CORS policy in Electron

[brownsugar]

Version

6.0.0-beta.21 and up

Browser and OS info

Electron 17.2.0 / MacOS 12.2.1

Steps to reproduce

1. Install Quasar and set the configs for Election mode.
2. Install @vue/devtools@6.0.0-beta.21
3. Run quasar dev -m electron --devtools to start a development server.
4. Now Vue Developer Tools window will popup first, next will be the main Quasar app window.
5. Open Chrome dev tool in Quasar app window, we can see the error message:

Access to XMLHttpRequest at 'http://localhost:8098/socket.io/?EIO=4&transport=polling&t=N-x9F79' from origin 'http://localhost:8080' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

What is expected?

The Socket.io server should correctly handle CORS requests.

What is actually happening?

Request was blocked by the CORS policy.

---

Since Socket.io v3, CORS was disabled by default, when I update @vue/devtools from 6.0.0-beta.20 to 6.0.0-beta.21, the required version of socket.io dependency was updated from ^2.0.4 to ^4.4.0, and the socket.io server in electron-shell doesn't properly handle CORS.