React Native, Invariant Violation: Native module cannot be null.

🐛 Bug Report

hey, hi! i have a similar issue (i think) here: https://github.com/facebook/jest/issues/2208, but this issue is quite old, and i have followed the solutions there, but none worked for me.

at first, i encountered this error for running jest:

/home/nrion/Desktop/mobile-ui/PriceInsight_app/node_modules/react-native-onesignal/index.js:4
    import { NativeModules, NativeEventEmitter, NetInfo, Platform } from 'react-native';
    ^^^^^^
    
    SyntaxError: Unexpected token import

    > 1 | import OneSignal from 'react-native-onesignal';
      2 | 
      3 | export const STORE_TIMEFRAME = 'STORE_TIMEFRAME';
      4 | export const STORE_TIMEFRAMES = 'STORE_TIMEFRAMES';
      
      at ScriptTransformer._transformAndBuildScript (../../../../../usr/lib/node_modules/jest-cli/node_modules/jest-runtime/build/script_transformer.js:316:17)
      at Object.<anonymous> (src/actions/subscription.js:1:387)
      at Object.<anonymous> (src/reducers/subscription.js:1:402)

so i went ahead and added react-native-onesignal to package.json as such:

"transformIgnorePatterns": [
      "node_modules/(?!(react-native-onesignal|react-native-login|react-native-elements)/)"
    ]

so that solved my problem. but here comes another problem:

 Invariant Violation: Native module cannot be null.

    > 1 | import OneSignal from 'react-native-onesignal';
      2 | 
      3 | export const STORE_TIMEFRAME = 'STORE_TIMEFRAME';
      4 | export const STORE_TIMEFRAMES = 'STORE_TIMEFRAMES';
      
      at invariant (node_modules/fbjs/lib/invariant.js:42:15)
      at new NativeEventEmitter (node_modules/react-native/Libraries/EventEmitter/NativeEventEmitter.js:37:31)
      at Object.<anonymous> (node_modules/react-native-onesignal/index.js:9:33)

i tried mocking OneSignal, but this is what happens when I do that:

 Cannot find module 'OneSignal' from 'Main.test.js'

    > 1 | import React from 'react'
      2 | import { shallow } from '../../jest-setup'
      3 | import configureStore from 'redux-mock-store'
      4 | import OneSignal from 'react-native-onesignal'
      
      at Resolver.resolveModule (../../../../../usr/lib/node_modules/jest-cli/node_modules/jest-resolve/build/index.js:169:17)
      at Object.<anonymous> (src/__tests__/Main.test.js:1:108)

To Reproduce

Steps to reproduce the behavior:

1. npm install react-native-onesignal
2. run jest

Expected behavior

test passes, writes a snapshot

[thymikee]

Oh, you need to mock the react-native-onesignal, not OneSignal. Mocking is for modules and OneSignal is not a module - it’s a variable name.

jest.mock('react-native-onesignal', () => {
  return {
    addEventListener: jest.fn(),
    removeEventListener: jest.fn(),
    inFocusDisplaying: jest.fn()
  }
})

should do the trick

[Pallavisoba]

Hi, I’m a having an issue while running my app “Invariant Violation: Native module cannot be null”

Can someone please help for that Thanks