Infinite loop callbacks_poll React Native Debugger - react-native

I see this endless loop in the debugger network pane, both in Chrome and React Native Debugger using iOS Simulator and RN 0.49.5.
It basically shows and endlessly increasing number of network requests with the name callbacks_poll. I even see them when return null from my main App file. Tried clearing cache, resetting simulator, hard restart, etc. Any idea how to stop this?

I just came across to the same error, with a bit of search found that the reason was the realm library.
If you do use realm, you can follow up the github issue here: https://github.com/realm/realm-js/issues/1538

Related

Expo debug remote JS causes unresponsiveness in UI

I upgraded a react native project recently from expo SDK 36 to 38. It compiles now, but anytime I click on "Debug Remote JS", it causes the UI to become slow and unresponsive, only occasionally picking up the on click events. I created a bare bones project to duplicate it. To verify, either run expo init from cli or here's a project https://github.com/seniordevops/tab-application.git. Click the tabs without the debugger on, then turn on debug remote JS and watch the slow down. Happens on both Mac and PC. Any ideas on the root cause?
This is mostly due to the fact that the clock on your PC and mobile are not synchronized.
You either have to synchronize them or have the phone clock one second earlier than your PC/Mac.
I suspect the reason could be an upstream problem of react-native. Please check this expo-cli issue:
https://github.com/expo/expo-cli/issues/2405
a maintainer reports:
when you are debugging on your device, the javascript is being
executed in your browser on your computer :(

Stuck on Downloading Javascript Bundle 100% - Expo

I guess that I've tried every solution that exists on the internet about this issue, and nothing works, and I don't even know where to look anymore. It started to happen from nowhere and I can't even open the app settings shaking the phone, it's completely stuck on this screen.
I cleaned up NPM, Yarn, Expo's caches and disabled the Remote Dev Tools.
I would be so much thankful for any help.
In my case it was due to the a remote debugger.
I left the remote debugging on, put the mac in sleep and when I turned it on again the iOS Simulator remained stuck at bundling 100%, irrespective of what I've tried (kill simulator, expo r -c, Reload app, etc.)
However, I could have realized the root cause earlier because on the physical device it was working the entire time.
Hope this saves someone some time.
You could try reverting to your last known working commit, then incrementally adding back the changes until this happens again. This often is a result of delaying hiding the splash screen (perhaps via AppLoading or SplashScreen) and then not hiding it because of some error in the app code preventing the code to hide it from being called.
Try Disable Debug Remote JS in the IOS Simulator
by clicking ctrl + cmd +Z on Mac
It works for me.
Seems like something is wrong with the dependencies, just close down the react-native environment ( android studio) and your IDE, just closing and restarting may work if not, check for updates or delete and reinstall your dependencies ( expo i )

"Unable to resolve module" debuggerWorker errors in recent react-native releases

I keep my project(s) relatively up to date with the latest RN releases. This error seems to be coming up more and more lately.
Error: Unable to resolve module `./debugger-ui/debuggerWorker.d9da4ed7` from ``:
None of these files exist:
* debugger-ui/debuggerWorker.d9da4ed7(.native|.native.js|.js|.native.json|.json|.native.ts|.ts|.native.tsx|.tsx)
Really makes it hard when trying to debug issues and a debugger statement does noting and errors are not reported to the browser tab where the console output goes.
I've already tried wiping node_modules. Is this a known issue with a concrete fix available?
Got stuck with this exact issue for hours. Just found that this occurs only on device where app is already installed with debug mode enabled.
I fixed it by:
uninstalling manually app from device (cmd+H to display simulator home) then long click on app icon and click on cross to delete app => this forces disabling debug mode,
then run app again from xcode.
Enabling debug mode after that works normally.
I had to come across a similar issue after updating #react-native-community/cli-debugger-ui to 4.2.1. Tried out several methods, nothing worked. Reverting #react-native-community/cli-debugger-ui back to 3.0.0 resolved the issue for me.
I closed the app (pressing home twice and swiping up), then started it again from the simulator and it worked.
Happens to me recently using expo and android.
The solution was to clear all Expo Go data:
Long press the Expo go icon
Then select App info
At the bottom of the screen, press Clear Data
And press Clear all data
Relaunch expo go and the react native app

Successfully setting up React Native in Visual Studio Code for Mac

I'm having a real difficult time setting up React Native on Visual Studio Code on my mac. I have read multiple tutorials and watched youtube and Lynda videos on how to do it - follow the steps exactly as they are presented, but still it doesn't completely works. It seems like every other terminal command I run gets an error.
I have managed to get it running on my physical iPhone and in the Android emulator. But when I try get it up and running on my iOS simulator using the appropriate terminal command, it won't work. The simulator opens, but then the terminal seems to get stuck loading and the app isn't showing in the simulator. There's no error, but it doesn't run.
Another thing is that I don't seem to find the index.ios and index.android files respectively - just a single App.js file.
I guess what I'm asking for is a good thorough guid on setting it up. Most guides I come across seem to leave out or under-explain certain steps, assuming that you already understand certain concepts. Please post a link if you know any super guides :) Thanks!

Chrome debugging and slowness in RN apps

Every now and then, my iOS simulator becomes extremely slow. Am unable to deterministically say when this happens. One solution seems to be "Reset Content and Settings.." effectively turning off chrome debugging and then restarting the app. Has anyone faced this issue ? If yes, are there any solutions to continue debugging in Chrome without any performance hit.
Didnt face this on the previous versions. Now on ^0.35
React Native console.log will slow everything down if Chrome tab displaying the log messages is not visible. You can try react native debugger and see if you have same issues.
https://github.com/jhen0409/react-native-debugger