React-native: "Invariant Violation: Native module cannot be null" when running tests after upgrade from 0.38 to 0.39.1

[jcollum]

Originally reported here: https://github.com/facebook/jest/issues/2382#issuecomment-268331120

Description

https://github.com/jcollum/kishar-nine/tree/02-routing -- RN 0.38

https://github.com/jcollum/kishar-nine/tree/03-redux-counter -- RN 0.39.1

After upgrading to 0.39.1 the tests fail:

$ npm test

> [email protected] test /Users/collumj/research/kishar-nine
> jest

 FAIL  test/index.android.js
  ● Test suite failed to run

    Invariant Violation: Native module cannot be null.

      at invariant (node_modules/fbjs/lib/invariant.js:38:15)
      at Linking.NativeEventEmitter (node_modules/react-native/Libraries/EventEmitter/NativeEventEmitter.js:32:1)
      at new Linking (node_modules/react-native/Libraries/Linking/Linking.js:119:141)
      at Object.<anonymous> (node_modules/react-native/Libraries/Linking/Linking.js:191:16)
      at Object.get Linking [as Linking] (node_modules/react-native/Libraries/react-native/react-native.js:91:22)
      at Object.<anonymous> (node_modules/react-native-experimental-navigation/NavigationRootContainer.js:15:36)

Could the use of `react-native-experimental-navigation` be the issue? It's in the Router code I think. 

Reproduction

Clone the repo.

$ rm -rf node_modules/ && git checkout 02-routing && npm install --silent && npm test

Tests pass.

rm -rf node_modules/ && git checkout 03-redux-counter && npm install --silent && npm test

Tests fail with above error message.

Additional Information

$ versions
npm 3.10.8
node v6.9.1
OS:
ProductName:    Mac OS X
ProductVersion: 10.11.6
BuildVersion:   15G31

$ cat node_modules/react-native/package.json|grep version
  "version": "0.39.2"

$ react-native --version
react-native-cli: 1.2.0
react-native: 0.39.2

[vinnyoodles]

I'm getting the same error, this is my package.json

{
  "scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest",
    "ios": "react-native run-ios && react-native log-ios",
    "android": "react-native run-android && react-native log-android",
    "link": "react-native link"
  },
  "dependencies": {
    "react": "15.4.1",
    "react-native": "^0.39.2",
    "react-native-cli": "^2.0.1",
    "react-native-fbsdk": "^0.4.0",
    "react-native-maps": "^0.12.2",
    "react-redux": "^5.0.1",
    "redux": "^3.6.0",
    "redux-thunk": "^2.1.0"
  },
  "devDependencies": {
    "babel-jest": "17.0.2",
    "babel-preset-react-native": "1.9.0",
    "jest": "17.0.3",
    "react-test-renderer": "15.4.1"
  },
  "jest": {
    "preset": "react-native"
  }
}

[brentvatne]

this error results from creating a NativeEventEmitter on a module that hasn't been mocked

[jcollum]

I don't know what to do with that information. I've searched for NativeEventEmitter in all the js in my node_modules folder and there are 141 occurences -- all in the reactnative library.

[bufke]

I'm getting this too on a very new RN project with jest. Even a trivial test like add two numbers fails. Guessing one of my dependencies includes react-native-experimental-navigation as a dependency. I'm not using it directly.

[michaelAndersonCampingWorld]

I get this as well. I have several components that reference Linking module in componentDidMount and componentDidUnmount, but the only one that fails is the one where I'm adding/removing event listeners. I am also requiring react-native-mock/mock in the jest setup.

[jcollum]

react-native-experimental-navigation

I know mine is, react-native-router-flux (source). Should we report this over there instead?

[MrToph]

Same error here using NetInfo

[bufke]

This fixed it for me (though obviously is a hacky workaround)

[jcollum]

I'll give that a shot thanks @bufke

[jcollum]

@bufke Looks like it worked. But I don't know why, which would be great. Thanks much! Full solution:

1. create setup.js in /test (I despise Jest's __ notation 👎, I want test stuff to be in one directory )
2. add this to setup.js:

jest.mock('Linking', () => {
  return {
    addEventListener: jest.fn(),
    removeEventListener: jest.fn(),
    openURL: jest.fn(),
    canOpenURL: jest.fn(),
    getInitialURL: jest.fn(),
  }
})

1. Set your jest node in package.json to this:

"jest": {
        "preset": "react-native",
        "testRegex": "./test/[^setup].*.js$",
        "mocksPattern": "./test/mocks/.*.js$",
        "transformIgnorePatterns": ["node_modules/(?!react-native|native-base|react-clone-referenced-element)"],
        "setupFiles": [
            "./test/setup.js"
        ]
    },

[linhnh123]

@jcollum I followed 3 step of you, but it still not working.
This fixed it for me:

jest.mock('react-native', () => ({
    NetInfo: {
        addEventListener: jest.fn(),
        fetch: () => {
            return {
                done: jest.fn()
            }
        }
    },
    NativeModules: {
        RNPasscodeStatus: {
            supported: jest.fn(),
            status: jest.fn(),
            get: jest.fn()
        }
    },
    Dimensions: {
        get: () => ({
            width: jest.fn(),
            height: jest.fn()
        })
    },
}));

[SupriyaKalghatgi]

Adding setup.js worked initially and I did nothing later, it failed again.
Can anyone help me on this?