React unit test with jest in es6 - node.js

Question

I am pretty new in react world and trying to write simple friendslist application. I wrote my friends store in es6 style and using babel as transpiler from es5 to es6.
import AppDispatcher from '../dispatcher/app_dispatcher';
import { EventEmitter } from 'events';
import FRIENDS_CONST from '../constants/friends';
const CHANGE_EVENT = 'CHANGE';
let friendsList = [];
let add = (name) => {
let counter = friendsList.length + 1;
let newFriend = {
id: counter,
name: name
};
friendsList.push(newFriend);
}
let remove = (id) => {
let index = friendsList.findIndex(e => e.id == id);
delete friendsList[index];
}
let FriendsStore = Object.assign({}, EventEmitter.prototype, {
getAll: () => {
return friendsList;
},
emitChange: () => {
this.emit(CHANGE_EVENT);
},
addChangeListener: (callback) => {
this.on(CHANGE_EVENT, callback);
},
removeChangeListener: (callback) => {
this.removeListener(CHANGE_EVENT, callback);
}
});
AppDispatcher.register((action) => {
switch (action.actionType) {
case FRIENDS_CONST.ADD_FRIENDS:
add(action.name);
FriendsStore.emitChange();
break;
case FRIENDS_CONST.REMOVE_FRIENDS:
remove(action.id);
FriendsStore.emitChange();
break;
}
});
export default FriendsStore;
Now I want to test my store and wrote the unit test also in es6
jest.dontMock('../../constants/friends');
jest.dontMock('../friends_store');
describe('FriendsStore', () => {
import FRIENDS from '../../constants/friends';
import AppDispatcher from '../../dispatcher/AppDispatcher';
import FriendsStore from '../friends_store';
let FakeAppDispatcher;
let FakeFriendsStore;
let callback;
let addFriends = {
actionType: FRIENDS.ADD_FRIENDS,
name: 'Many'
};
let removeFriend = {
actionType: FRIENDS.REMOVE_FRIENDS,
id: '3'
};
beforeEach(function() {
FakeAppDispatcher = AppDispatcher;
FakeFriendsStore = FriendsStore;
callback = AppDispatcher.register.mock.calls[0][0];
});
it('Should initialize with no friends items', function() {
var all = FriendsStore.getAll();
expect(all).toEqual([]);
});
});
When I execute the test with statement npm test, I've got the error message:
> react-starterify#0.0.9 test /Volumes/Developer/reactjs/app5
> echo "Error: no test specified"
Error: no test specified
What am I doing wrong? The file structure looks as follow:

Answer 1

I did it following the tutorial:
npm install --save-dev jest babel-jest babel-preset-es2015 babel-preset-react react-test-renderer
then
add to package.json
"scripts": {
"test": "jest"
},
"jest": {
"testPathDirs": [
"src/main/resources/web_pages/__tests__"
]
},
Result:
PASS src/main/resources/web_pages/__tests__/modules/utils/ValidationUtil.spec.js (5.214s)
✓ ValidateEmail (5ms)
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 6.092s, estimated 7s
Ran all test suites.

Answer 2

To test ES6 syntax and JSX files, they need to be transformed for Jest. Jest has a config variable where you can define a preprocessor (scriptPreprocessor). You can use the babel-jest preprocessor:
Make the following changes to package.json:
{
"devDependencies": {
"babel-jest": "*",
"jest-cli": "*"
},
"scripts": {
"test": "jest"
},
"jest": {
"scriptPreprocessor": "<rootDir>/node_modules/babel-jest",
"testFileExtensions": ["es6", "js"],
"moduleFileExtensions": ["js", "json", "es6"]
}
}
And run:
$ npm install