[HMR][Redux] Updating reducer code disconnect the app from the store

[Fr33maan]

Is this a bug report?

Yes it might be, it's now 10 hours I'm trying everything to get rid of it but I still don't understand what is going on.

Have you read the Contributing Guidelines?

Yes

Environment

OS: Linux 3.16
Node: 8.2.1
Yarn: 0.27.5
npm: 5.3.0
Watchman: 4.7.0

Packages: (wanted => installed)
react-native: 0.48.4 => 0.48.4
react: 16.0.0-alpha.12 => 16.0.0-alpha.12

Target Platform: Android (6)

Steps to Reproduce

(Write your steps here:)

1. Click on the button, action gets dispatched and component is updated
2. Edit and save App/Redux/SearchRedux
3. Click on the button, actions gets dispatched and component is NOT updated

Expected Behavior

After editing a reducer, I would expect my component to still gets store updates and rerender if the connected state changes.

Actual Behavior

The component is not updated once I've edited and saved a reducer. I must restart the server to reconnect the Component to the store.

Reproducible Demo

git clone https://github.com/l1br3/ReactNative-Redux-HMR-Broken
npm run freshInstall

If use of iOs, look at the script in package.json.

I suspect react-navigation to be responsible of that because HMR does not support functionnal components but as HMR globally works, maybe it's just a ReactNative bug.
#13240

I tried many things bug I cannot get it work. I've also posted a question on SO in case it's just a misconfiguration but the more I dig into it, the less I understand what happens.

[Fr33maan]

I tried to upgrade to API 26 which give me now the ability of just reloading the app instead of restarting the server but I loose my state anyway.

PS: API 26 with remote debuging caused crash for me on AVD

[Fr33maan]

Solved, it was a misconfiguration.
It's very complicated to understand how it works, if replaceReducer is in the wrong file, then HMR does very strange things and mess with the state.
The solution was super easy, I just had to place it at the good place.

If someone experiences issues with Hot Module Replacement, React Native, Redux you can find a complete exemple, fully working on the repo linked in the issue.