Bug: 'SharedArrayBuffer' is not defined (using v^17.0.2)

[baalimago]

Issue:

It says 'SharedArrayBuffer' is not defined when attempting to run project using a shared array buffer

How to recreate:

1. npx create-react-app test-project
2. In App.js, add function const test = () => { const b = new SharedArrayBuffer(1024); }
3. Attempt to start app
4. Expect:
   

System:

package.json:

{
  "name": "shared_array_buffer_test",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^5.11.4",
    "@testing-library/react": "^11.1.0",
    "@testing-library/user-event": "^12.1.10",
    "react": "^17.0.2",
    "react-dom": "^17.0.2",
    "react-scripts": "4.0.3",
    "web-vitals": "^1.0.1"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

Windows 11 (insider build 10.0.22000 Build 22000)
WSL2 - Ubuntu 20.04 LTS

[eps1lon]

Thanks for the feedback.

This lint error originates from react-scripts which is released from facebook/create-react-app. You want to open a new issue in their repository

[baalimago]

I don't think it's a lint issue.

It's caused by some CORS headers not being set properly (see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer) in the react development server. It should've been fixed in react >=17.0.2 #20831, but it doesn't seem to work for some reason.

I might add that it's not wsl2 related, I did the same test on ubuntu 20.04 and the behaviour is the same.

[siddharthroy12]

I'm having the same issue