React Native iOS simulator "Connect to Metro to Develop Javascript"

user_5160929 0
Viewed 10247

I'm running a react native app and constantly running into the issue of the app not connecting to the code to do automatic updates.

Things I've tried:

  • Reloading main.jsbundle via the following command: npx react-native bundle --entry-file index.js --platform ios --dev false --bundle-output ios/main.jsbundle --assets-dest ios/assets
  • Completely removing node and react native from my computer
  • Restarting my computer
  • Running on a physical device and running on the simulator
  • Cleaning derived data in Xcode

This is the screen on starting up, which offers the advice, "Connect to Metro to develop JavaScript."

Connect to Metro to develop JavaScript.

From the metro bundler that automatically starts up, I get this message when I type 'r' to reload that says, "React Native: No apps connected."

"No apps connected"

I'm using 0.61 and always have been.

What else should I try?

EDIT

I was able to get it working by restarting my computer (again).

Every once in a while, a restart does the trick, yet most of the time it doesn't work. There still has to be a more reliable way of fixing this.

metro-bundler react-native ios
7 Answers

Dev menu looks like:

enter image description here

In my case it could happen after recreating main.jsbundle

  1. Open any installed ios simulator.
  2. install your app (npm run ios)
  3. press cmd + d being focused on simulator
  4. choose configure bundler

bundler preferences:

enter image description here

  1. bundler address - 127.0.0.1
  2. port - 8081

then simulator will reconnect itself

user_142305110

I had the same issue some time before. Suddenly the App doesn't work anymore if starting only with XCode. I have to start the metro-bundler via CLI... and if running, I had to use "XCode" to run the App. As the metro-bundler still running in the background, XCode didn't start it's own, and the connection could be established.

I've described my request here... which sounds a bit similar to yours. Now I don't have any issues anymore if starting from xcode directly. Maybe this was caused of an upgrade of XCode (my current XCode-Version: 10.3)

user_12566970

Go to device simulator and shake then configure bundler for example 127.0.0.1:8081

user_82741930

If the above solutions won't work just make sure that you select the scheme as a debug not release. **

How to edit scheme :

** Xcode 12.4 => Product > scheme > edit scheme > run > info > Build Configuration > select debug.

user_133720070

Are you having this issue while testing on the phone? I think you should enable the wifi in same network with computer.

user_109127270

Hopefully this works for more people than just myself:

  1. Restart your computer

  2. Run react-native start inside the project directory.

  3. Open ProjectName.xcworkspace in Xcode (should be in the ios folder of your project directory.

  4. Launch the simulator through Xcode (Upper left corner)

user_51609290

Try this while you have your metro bundler opened,

1-delete app and rerun

2-popup message will appear "this app would like to connect to other app on network" Press OK

3- shake your iphone --> configure bundler -->Reset to default

user_131743640
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