[FEATURE] support Jest mocking

[vovkind]

I'm submitting a ... (check one with "x"):

• [x ] bug report
• feature request
• documentation issue

Bug report

Current behavior:

Unable to mock the plugin as part of unit testing.
Tried to mock the plugin as following: jest.mock('react-native-launch-navigator', () => 'LaunchNavigator');

Getting exception on running npm test:

● Test suite failed to run

Invariant Violation: Native module cannot be null.

  23 | import Sound from 'react-native-sound';
> 24 | import LaunchNavigator from 'react-native-launch-navigator';
     |                                                          ^

  at invariant (node_modules/invariant/invariant.js:40:15)
  at new NativeEventEmitter (node_modules/react-native/Libraries/EventEmitter/NativeEventEmitter.js:36:27)
  at RNLogger._addListeners (node_modules/react-native-launch-navigator/RNLogger.js:11:33)
  at new RNLogger (node_modules/react-native-launch-navigator/RNLogger.js:48:10)
  at Object.<anonymous> (node_modules/react-native-launch-navigator/index.js:24:14)
  at Object.<anonymous> (src/utils/CommonFunctions.js:24:58)

Mocking of plugin is not working

Expected behavior:

Unit testing with Jest should work

Mocking of the plugin should be successfully performed.

Steps to reproduce:

npm test

with some code containing import to react-native-launch-navigator

Environment information

• React Native version
  • 0.59.10
• Other React Native modules/components/tools
  • "dependencies": {
    "jetifier": "1.6.4",
    "@bugfender/rn-bugfender": "1.0.0",
    "@ptomasroos/react-native-multi-slider": "1.0.0",
    "@react-native-community/async-storage": "1.3.3",
    "@react-native-community/netinfo": "3.2.1",
    "axios": "0.19.0",
    "codacy-coverage": "^3.4.0",
    "enzyme": "3.9.0",
    "enzyme-adapter-react-16": "1.12.1",
    "enzyme-to-json": "3.3.5",
    "i18n-js": "3.2.1",
    "native-base": "2.12.1",
    "prop-types": "15.7.2",
    "react": "16.8.3",
    "react-dom": "16.8.6",
    "react-native": "0.59.10",
    "react-native-background-geolocation": "3.2.2",
    "react-native-camera-kit": "8.0.0",
    "react-native-device-info": "2.1.2",
    "react-native-firebase": "5.5.5",
    "react-native-gallery-swiper": "1.22.2",
    "react-native-gesture-handler": "git+https://github.com/ShaMan123/react-native-gesture-handler.git",
    "react-native-indicator": "1.0.0",
    "react-native-launch-navigator": "1.0.5",
    "react-native-linear-gradient": "2.5.4",
    "react-native-modal": "11.0.1",
    "react-native-permissions": "2.0.0-alpha.1",
    "react-native-sound": "0.11.0",
    "react-native-svg": "9.6.2",
    "react-native-svg-animated-linear-gradient": "0.3.2",
    "react-native-svg-uri": "1.2.3",
    "react-native-vector-icons": "6.5.0",
    "react-native-webview": "5.11.0",
    "react-native-wheel-picker-extended": "1.2.0",
    "react-navigation": "3.6.1",
    "react-redux": "6.0.1",
    "redux": "4.0.1"
    },
    "devDependencies": {
    "@babel/core": "7.5.0",
    "@babel/runtime": "7.5.0",
    "@types/jest": "24.0.20",
    "babel-core": "7.0.0-bridge.0",
    "babel-jest": "24.9.0",
    "eslint": "6.6.0",
    "eslint-config-airbnb": "18.0.1",
    "eslint-plugin-import": "2.18.2",
    "eslint-plugin-jsx-a11y": "6.2.3",
    "eslint-plugin-react": "7.16.0",
    "jest": "24.9.0",
    "metro-react-native-babel-preset": "0.53.1",
    "prettier-eslint": "8.8.2",
    "react-native-version": "3.0.0",
    "react-test-renderer": "16.11.0",
    "ts-jest": "24.1.0",
    "typescript": "3.6.4"
    },
    "jest": {
    "preset": "react-native",
    "snapshotSerializers": [
    "enzyme-to-json/serializer"
    ],
    "globals": {
    "window": {}
    },
    "transform": {
    "^.+\.ts?$": "ts-jest",
    "^.+\.tsx?$": "ts-jest",
    "^.+\.js$": "./node_modules/react-native/jest/preprocessor.js"
    },
    "moduleFileExtensions": [
    "ts",
    "tsx",
    "js",
    "jsx",
    "json",
    "node"
    ],
    "moduleNameMapper": {
    "^.+\.(css|less|scss)$": "identity-obj-proxy"
    },
    "transformIgnorePatterns": [],
    "setupFiles": [
    "./jestSetup.js"
    ]
    }
    }
• Dev machine OS and version, e.g.
  • OSX Mojave 10.14.5
    • sw_vers
  • Windows 10
    • winver

Console output

console output

// Paste any relevant JS/native console output here

[dpa99c]

I consider this a feature request, not a bug because the module actually works fine in reality, it just doesn't currently support mocking of its functionality.