React-redux: setState warning using v5.0.0-rc.1 with redux-form.

[mariuszdev]

The following error appears using [email protected] when I am unmounting component which renders redux-form's <Field /> component only if the <Field /> has been previously focused. I know that it seems like problem with redux-form but when I switch back to [email protected] everything works fine.

warning.js:36 Warning: setState(...): Can only update a mounted or mounting component. This usually means you called setState() on an unmounted component. This is a no-op. Please check the code for the Connect(ConnectedField) component.

Tested on OSX and [email protected] (64-bit) and [email protected] (12602.2.14.0.7)

How to reproduce

1. Clone the repository https://github.com/pilaas/react-redux-bug
2. yarn
3. npm run start
4. Open browser http://localhost:8080
5. Open console and enter type store.dispatch({type: 'SHOW_FORM'});
6. Focus newly appeared input component
7. Enter store.dispatch({type: 'HIDE_FORM'}); in console
8. Experience warning

[timdorr]

Not to strawman/sidetrack too much, but why are you storing that kind of state in your store? It doesn't seem to be a business-level concern, just UI state. That kind of thing is best left to local React state instead.

[mariuszdev]

It's just example project to demonstrate the problem. Programming patterns are not the case here. I don't need a workaround, I just report the bug (?).

[markerikson]

Haven't tried to repro this yet, but gotta say, this is a _great_ bug report. Scenario description, error message, "How to repro", _and_ a cloneable repo that can reproduce the issue. Thanks!

[jimbolla]

I plan to take a loot at this today. Thanks, @pilaas.

[jimbolla]

Ah. The good news is this seems to be fixed if built against the head of next branch. @timdorr Any chance we can push an rc2?

[timdorr]

Pushed out a quick rc2 just now. I'll try to do 5.0.0 final tomorrow once I'm done with some stuff related to my move this weekend. Draft is ready for the release notes.