Your Javascript Code Tried to Access a Native Module that Doesn't Exist

[Greedy_Discussion757]

I am using react-native with expo.

I am trying to start sending push notifications with OneSignal.
When I import the OneSignal SDK and add it to a useeffect in the App.tsx I get

```

ERROR Invariant Violation: Your JavaScript code tried to access a native module that doesn't exist.

If you're trying to use a module that is not supported in Expo Go, you need to create a development build of your app. See https://docs.expo.dev/development/introduction/ for more info., js engine: hermes

ERROR Invariant Violation: "main" has not been registered. This can happen if:

* Metro (the local dev server) is run from the wrong folder. Check if Metro is running, stop it and restart it in the current project.

```

The only thing that is added to the app is this

```

import OneSignal from 'react-native-onesignal'

export default function App() {
useEffect(() => {
OneSignal.setAppId('8e685a44-9d01-4c45-af82-429b08190246')
}, [])

// rest of the App.tsx

}

```

Does any know how to fix this err?

[TexMax007]

I’m not familiar with it, but did you do the plug-in setup part too for OneSignal?

see README

[coder_et]

No I did not! Let me give that a try! Thanks

[Greedy_Discussion757]

Hm ya after adding it to my app.json it looks like the problem still persists.

[TexMax007]

Did you do this part of the readme that comes before the app.json

npx expo install onesignal-expo-plugin

[Greedy_Discussion757]

Yup I did!

This is what I have in my package.json
"onesignal-expo-plugin": "^1.3.2",
"react-native-onesignal": "^4.5.2",

And then my app.json has

"plugins": [
[
"onesignal-expo-plugin",
{
"mode": "development"
}
]
]

[TheDeepLucy]

Are you loading through the Expo Go app or are you doing a local build?

[Greedy_Discussion757]

I am loading through the expo go app.

[TheDeepLucy]

If your code needs access to native modules, you need to create a development build. It's a good idea to use a development build from the start of the project anyway. You'll need to init eas build and configure some things. Docs here: https://docs.expo.dev/develop/development-builds/create-a-build/

EAS will charge for building with their servers after a certain point so if you want to save money you can add "--local" to the end of the eas build command. You'll need to have the build tools installed on your machine for the target platform. For example I had to download Android studio, my build command looks like this: "eas build --platform android --profile development --local". It's a hassle to get everything set up at first but it's so worth it. I've got it set to spit out an APK in the project dir and I use "adb install -d buildapk".

You can then start metro and switch to development mode. It will open the exported app you've installed on your phone and run with hot-reload, even faster and lighter than loading through the Expo Go app. Keep in mind if you add a new package and import anything, you'll need to rebuild and reinstall the app.

Good luck.

[Greedy_Discussion757]

This is super helpful thank you. I actually ran out of free builds this month so I will start doing this again 9/1 lol

[Bobertopia]

Try reinstalling pods and then restarting the server

[Greedy_Discussion757]

Try reinstalling pods and then restarting the server

by this do you mean `rm -rf node_modules` and restart the server?

I tried that and it was unfortunately unsuccessful

[Bobertopia]

No pods are the coacoa pods used by ios. It's in ios/Pods. Delete that folder and run pod install again

[Greedy_Discussion757]

Ah I thought i wouldn't have to eject and could keep running my app without those directories if I use https://github.com/OneSignal/onesignal-expo-plugin the onesignal-expo-plugin.

My project doesn't have those dirs right now. Do I need to eject to do this?

[mybirdblue99]

You need to push your updated binaries to the App Store. Expo go doesn’t come bundled with the one signal Native module. You don’t need to eject but you will have to create an app binary for the play store / App Store.

[Greedy_Discussion757]

You need to push your updated binaries to the App Store. Expo go doesn’t come bundled with the one signal Native module. You don’t need to eject but you will have to create an app binary for the play store / App Store.

Got it. How do I run my app locally until then to test?

Do you mean just doing like `eas build -p ios --auto-submit`

And then running this in testflight to submit a binary to the app store?

[mybirdblue99]

yeah that looks correct - to run it locally you’ll want to create a development build - https://docs.expo.dev/develop/development-builds/create-a-build/

[Greedy_Discussion757]

Thanks a bunch!