React Native Test with Jest impossible to mock Geolocation - testing

Question

I tried to find a solution on the web and I found this Stackoverflow answer, I followed the instructions but I was blocked:
TypeError: Cannot set property 'geolocation' of undefined
So when I remove the solution my error is:
ReferenceError: navigator is not defined
My package.json looks like this:
"dependencies": {
"eslint-plugin-react-native": "^3.2.0",
"prop-types": "^15.6.0",
"react": "16.0.0",
"react-native": "0.51.0",
},
"devDependencies": {
"babel-core": "^6.26.0",
"babel-eslint": "^8.1.2",
"babel-jest": "^22.4.1",
"babel-preset-react-native": "4.0.0",
"enzyme": "^3.3.0",
"enzyme-adapter-react-16": "^1.1.1",
"eslint": "^4.14.0",
"eslint-plugin-react": "^7.5.1",
"jest": "^22.4.2",
"jest-enzyme": "^6.0.0",
"react-dom": "^16.2.0",
"react-scripts": "^1.1.1",
"react-test-renderer": "16.0.0-beta.5"
},
"jest": {
"preset": "react-native",
"moduleFileExtensions": [
"js",
"jsx"
],
"moduleDirectories": [
"node_modules"
],
"transformIgnorePatterns": [
"node_modules/(?!(jest-)?react-native|react-navigation)"
],
"moduleNameMapper": {
"\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/assetsTransformer.js",
"\\.(css|less)$": "<rootDir>/assetsTransformer.js"
},
"verbose": true
},
"plugins": [
"react",
"react-native"
],
"ecmaFeatures": {
"jsx": true
},
"env": {
"react-native/react-native": true
}
And my test is just:
test('Map Component', () => {
// create the snapshot
const tree = renderer.create(<Map/>).toJSON();
// test the snapshot
expect(tree).toMatchSnapshot();
});
The error is on this line, on the navigator:
navigator.geolocation.getCurrentPosition((position) => {
For the moment I am not testing my component with the navigator. I hope some of you have a solution, please.

Answer 1

Add this in your jest setup.js:
global.navigator = {
geolocation: {
clearWatch: jest.fn(),
getCurrentPosition: jest.fn((success, failure, options) => {
success({
coords: {
longitude: 60,
latitude: 60,
},
});
}),
stopObserving: jest.fn(),
watchPosition: jest.fn(),
},
};
The setup.js file is the one you specify in your package.json file. i.e:
"jest": {
"setupFiles": [
"<rootDir>/__tests__/setup.js"
],
...