Error using plugin in managed Expo app

[azizsaad]

Your Environment

• Plugin version: 4.1.10
• Platform: iOS
• OS version: iOS 16.4
• Device manufacturer / model: iPhone 14
• React Native version (react-native -v): 0.71.8 - Managed Expo application

Expected Behavior

Should be able to install and use the plugin

Actual Behavior

Getting the following error when installing the plugin:

Steps to Reproduce

1. ran npx expo install react-native-background-fetch
2. ios key in the Expo config file looks like this:

 ios: {
      supportsTablet: true,
      infoPlist: {
        UIBackgroundModes: ["fetch", "processing"],
        BGTaskSchedulerPermittedIdentifiers: ["com.transistorsoft.fetch"],
      },
      usesAppleSignIn: true,
    },

3. Add this to App.js file (entry point to project)

import App from "./app/app.tsx"
import BackgroundFetch from "react-native-background-fetch"

SplashScreen.preventAutoHideAsync()

function IgniteApp() {
  return <App hideSplashScreen={SplashScreen.hideAsync} />
}

registerRootComponent(IgniteApp)
bgWorker()

const addEvent = (taskId) => {
  // Simulate a possibly long-running asynchronous task with a Promise.
  return new Promise((resolve, reject) => {
    console.log(taskId)
    resolve(true)
  })
}

const initBackgroundFetch = async () => {

  const onEvent = async (taskId) => {
    console.log("[BackgroundFetch] task: ", taskId)

    await addEvent(taskId)

    BackgroundFetch.finish(taskId)
  }

  const onTimeout = async (taskId) => {
    console.warn("[BackgroundFetch] TIMEOUT task: ", taskId)
    BackgroundFetch.finish(taskId)
  }

  const status = await BackgroundFetch.configure({ minimumFetchInterval: 15 }, onEvent, onTimeout)

  console.log("[BackgroundFetch] configure status: ", status)
}

export const bgWorker = () => {
  console.log("bgWorker")
  return initBackgroundFetch()
}

export default IgniteApp

Context

• Install package and run a background task

Debug logs

[azizsaad]

cc @christocracy Added the new issue here - thanks!

[christocracy]

https://github.com/transistorsoft/react-native-background-fetch/blob/master/docs/INSTALL-EXPO.md#open_file_folder-appjson

You need to add "plugins" to your app.json

[azizsaad]

https://github.com/transistorsoft/react-native-background-fetch/blob/master/docs/INSTALL-EXPO.md#open_file_folder-appjson

You need to add "plugins" to your app.json

Sorry for not clarifying this in the original issue, but I believe I have:

 plugins: [
      "react-native-background-fetch", // background worker
      [
        "expo-image-picker", // image picker
        {
          photosPermission: "Allow access your photos",
        },
      ],
    ],

[christocracy]

And what about the final section in the Setup doc: Re-build?

[azizsaad]

And what about the final section in the Setup doc: Re-build?

Does that not only apply to Android apps? as stated: "You must rebuild your Android app for the added plugins to be evaluated."

Side-question - this is akin to ejecting from a managed to bare workflow, is it not?

[christocracy]

I believe the word "Android" should be omitted.

Run it.

[azizsaad]

I believe the word "Android" should be omitted.

Run it.

I have - the ios and android directories have been created, but the error is still appearing

[christocracy]

I don't know

[azizsaad]

I am running this in the Expo Go app - should that make a difference with this error?

[christocracy]

I don't know. I have little experience with Expo Go and I'm too swamped with other stuff to look into it.

[azizsaad]

No worries - thank you anyways!!

[azizsaad]

Hey, I realised my issue.

I was testing this on the Expo Go app, which would not work as, if I understand correctly, the Expo Go app is only compatible with the Expo SDK packages.

I had to create a custom Development Client build with the EAS CLI, create this build on their infrastructure, scan the QR code and open the dev-client app on my physical phone (background-fetch doesn't work on iOS Simulator it seems)

[christocracy]

Great. Good work.