Testing Angular 2 service with mocha - unit-testing

Question

I am trying to implement unit tests for an Angular 2 app. But I can't get it it to work.
As test runner mocha is used and executed like this:
mocha -r ts-node/register -t 10000 ./**/*.unit.ts
Consider the following test file where I define two test cases which basically should do the same thing, but neither one is working.
shared.service.unit.ts
import { TestBed, async, inject } from '#angular/core/testing';
import { SharedService } from './shared.service';
import * as Chai from 'chai';
import 'mocha';
const expect = Chai.expect;
describe('SharedService', () => {
beforeEach(() => {
TestBed.configureTestingModule({
declarations: [SharedService],
providers: [SharedService]
});
});
it('should be an object',
inject([SharedService], (service: SharedService) => {
expect(service).to.be.an('object');
})
);
});
describe('SharedService without the TestBed', () => {
let service: SharedService;
beforeEach(() => {
service = new SharedService();
});
it('should be an object', () => {
expect(service).to.be.an('object');
});
});
The first one 'SharedService' uses the Angular Testing Utility. Running it gives:
ReferenceError: Zone is not defined
The second one 'SharedService without TestBed'does not use any Angular code (similar to this example from Angular 2 Testing guide). Running it gives:
TypeError: Reflect.getMetadata is not a function
After adding these lines to the test file:
import 'core-js/es6';
import 'core-js/es7/reflect';
import 'zone.js/dist/zone';
Both test cases give the same error (from zone.js\dist\zone.js):
TypeError: Cannot read property 'prototype' of undefined
What am I doing wrong?

Answer 1

Got it, just needed to import 'core-js/es7/reflect':
import 'core-js/es7/reflect';
import 'mocha';
import * as Chai from 'chai';
let expect = Chai.expect;
import { SharedService } from './shared.service';
describe('SharedService', () => {
let service: SharedService;
beforeEach(() => {
service = new SharedService();
})
it('should be an object', () => {
expect(service).to.be.an('object');
})
});

Answer 2

You need to load all that stuff - angular, ngzone, metadata, es shims, etc. - statically in the mocha's - or systemjs or whatever you use for setting this stuff up - configuration.