[Realworld] Unmounted component warning after logging out

[sodic]

Our Realworld example app sometimes throws the following error after the user logs out:

react-dom.development.js:67 Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function.
    at Navbar (http://localhost:3000/static/js/bundle.js:1414:19)
    at div
    at Container (http://localhost:3000/static/js/bundle.js:7948:23)
    at WithStyles (http://localhost:3000/static/js/bundle.js:20180:31)
    at UserSettingsPage (http://localhost:3000/static/js/bundle.js:3721:5)
    at AddHeader
    at http://localhost:3000/static/js/bundle.js:776:69

We should fix it :)

NOTE: We've recently solved a similar error, looking at the fix might help you.

[anup-a]

Hey 👋 @sodic . Great Project. Can I take up this one ?

[anup-a]

Strange but I was not able to reproduce the error. Can you guide me with some steps to reproduce?

[sodic]

Hey, @anup-a, sorry for the late response? If you're still interested, I can give you the instructions on reproducing it in a couple of hours.

[infomiho]

What I got so far:

• it only triggers if you are on a component that's wrapped with createAuthRequiredPage when logging out
• it seems that this warning was removed from React 18 completely: https://github.com/reactwg/react-18/discussions/82

I'll investigate a bit more to see if there is anything actionable or if we should move to upgrade to React 18 as a means of "fixing" this issue.

[sodic]

Finally they're removing this warning. Half of the code review fixes in my last company were either telling someone to use the isMounted check (when I'm the reviewer), or adding it (when I'm the author).

Anyway, if it's not a memory leak, we can just wait for React 18.

[sodic]

Since realworld no longer exists, I'm closing this.