[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.