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Testing Angular 2.0 RC1 Applications

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Testing Angular 2.0 RC1 Applications

Here is a quick-and-easy tutorial on testing Angular 2.0 RC1 applications.

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As mentioned on Friday, there's been quite a bit that's changed with Angular 2 between its Beta 9 and RC 1 releases. This article is an update to the Testing Angular 2 Applications I wrote in March. That tutorial was based on Angular 2.0 Beta 9. Rather than simply updating that tutorial and blog post for 2.0 RC1, I decided to create a new version for posterity's sake. The 2.0 Beta 9 version will remain on my blog and I've tagged the source on GitHub.

If you've already read the first version of Testing Angular 2 Applications, check out the diff of the Asciidoctor version to see what's changed.

What You'll Build

You'll learn to use Jasmine for unit testing controllers and Protractor for integration testing. See Angular 2's guide to unit testing if you'd like more information on testing and why it's important.

The best reason for writing tests is to automate your testing. Without tests, you'll likely be testing manually. This manual testing will take longer and longer as your codebase grows.

What You'll Need

  • About 15-30 minutes
  • A favorite text editor or IDE. I recommend IntelliJ IDEA
  • Git installed
  • Node.js and npm installed. I recommend using nvm

Get the Tutorial Project

Clone the angular2-tutorial repository, checkout the testing-start branch, and install its dependencies.

git clone https://github.com/mraible/angular2-tutorial.git
cd angular2-tutorial
git checkout testing-start
npm install


If you haven't completed the Getting Started with Angular 2.0 RC1 tutorial, you should peruse it so you understand how this application works. You can also simply start the app with npm start and view it in your browser at: http://localhost:5555/

Unit Test the SearchService

Create src/client/app/shared/search/search.service.spec.ts and setup the test's infrastructure using MockBackend and BaseRequestOptions.

import {
  beforeEachProviders,
  it,
  describe,
  expect,
  inject,
  fakeAsync,
  tick
} from '@angular/core/testing';
import { MockBackend } from '@angular/http/testing';
import { provide } from '@angular/core';
import { Http, ConnectionBackend, BaseRequestOptions, Response, ResponseOptions } from '@angular/http';
import { SearchService } from './search.service';

export function main() {
  describe('Search Service', () => {
    beforeEachProviders(() => {
      return [BaseRequestOptions, MockBackend, SearchService,
        provide(Http, {
          useFactory: (backend:ConnectionBackend, defaultOptions:BaseRequestOptions) => {
            return new Http(backend, defaultOptions);
          }, deps: [MockBackend, BaseRequestOptions]
        }),
      ];
    });
  });
}


If you run npm test, all tests will pass, but you don't see "Search Service" as a listed test. You can fix this by adding the first test of getAll(). This test shows how MockBackend can be used to mock results and set the response.

TIP: When you are testing code that returns either a Promise or an RxJS Observable, you can use thefakeAsync helper to test that code as if it were synchronous. Promises are be fulfilled and Observables are notified immediately after you call tick().

The test below should be on the same level as beforeEachProviders.

it('should retrieve all search results',
  inject([SearchService, MockBackend], fakeAsync((searchService:SearchService, mockBackend:MockBackend) => {
    var res:Response;
    mockBackend.connections.subscribe(c => {
      expect(c.request.url).toBe('app/shared/search/data/people.json');
      let response = new ResponseOptions({body: '[{"name": "John Elway"}, {"name": "Gary Kubiak"}]'});
      c.mockRespond(new Response(response));
    });
    searchService.getAll().subscribe((response) => {
      res = response;
    });
    tick();
    expect(res[0].name).toBe('John Elway');
  }))
);


Running npm testshould result in "12 tests completed". Add a couple more tests for filtering by search term and fetching by ID.

it('should filter by search term',
  inject([SearchService, MockBackend], fakeAsync((searchService:SearchService, mockBackend:MockBackend) => {
    var res;
    mockBackend.connections.subscribe(c => {
      expect(c.request.url).toBe('app/shared/search/data/people.json');
      let response = new ResponseOptions({body: '[{"name": "John Elway"}, {"name": "Gary Kubiak"}]'});
      c.mockRespond(new Response(response));
    });
    searchService.search('john').subscribe((response) => {
      res = response;
    });
    tick();
    expect(res[0].name).toBe('John Elway');
  }))
);

it('should fetch by id',
  inject([SearchService, MockBackend], fakeAsync((searchService:SearchService, mockBackend:MockBackend) => {
    var res;
    mockBackend.connections.subscribe(c => {
      expect(c.request.url).toBe('app/shared/search/data/people.json');
      let response = new ResponseOptions({body: '[{"id": 1, "name": "John Elway"}, {"id": 2, "name": "Gary Kubiak"}]'});
      c.mockRespond(new Response(response));
    });
    searchService.search('2').subscribe((response) => {
      res = response;
    });
    tick();
    expect(res[0].name).toBe('Gary Kubiak');
  }))
);


If you want to have tests continually run as you add them, you can run the following commands in separate shell windows:

npm run build.test.watch
npm run karma.start


NOTE: See Running Unit Tests on Karma to learn how to run your tests from IntelliJ IDEA.

Unit Test the SearchComponent

To unit test the SearchComponent, create a MockSearchProvider hat has spies. These allow you to spy on functions to check if they were called.

Create src/client/app/shared/search/mocks/search.service.ts and populate it with spies for each method, as well as methods to set the response and subscribe to results.

import { provide } from '@angular/core';
import { SpyObject } from './helper';

import { SearchService } from '../search.service';
import Spy = jasmine.Spy;

export class MockSearchService extends SpyObject {
  getAllSpy:Spy;
  getByIdSpy:Spy;
  searchSpy:Spy;
  saveSpy:Spy;
  fakeResponse:any;

  constructor() {
    super(SearchService);

    this.fakeResponse = null;
    this.getAllSpy = this.spy('getAll').andReturn(this);
    this.getByIdSpy = this.spy('get').andReturn(this);
    this.searchSpy = this.spy('search').andReturn(this);
    this.saveSpy = this.spy('save').andReturn(this);
  }

  subscribe(callback:any) {
    callback(this.fakeResponse);
  }

  setResponse(json:any):void {
    this.fakeResponse = json;
  }

  getProviders():Array<any> {
    return [provide(SearchService, {useValue: this})];
  }
}


In this same directory, create a helper.ts class to implement the SpyObject that MockSearchService extends.

import {StringMapWrapper} from '@angular/core/src/facade/collection';

export interface GuinessCompatibleSpy extends jasmine.Spy {
  /** By chaining the spy with and.returnValue, all calls to the function will return a specific
   * value. */
  andReturn(val: any): void;
  /** By chaining the spy with and.callFake, all calls to the spy will delegate to the supplied
   * function. */
  andCallFake(fn: Function): GuinessCompatibleSpy;
  /** removes all recorded calls */
  reset();
}

export class SpyObject {
  static stub(object = null, config = null, overrides = null) {
    if (!(object instanceof SpyObject)) {
      overrides = config;
      config = object;
      object = new SpyObject();
    }

    var m = StringMapWrapper.merge(config, overrides);
    StringMapWrapper.forEach(m, (value, key) => { object.spy(key).andReturn(value); });
    return object;
  }

  constructor(type = null) {
    if (type) {
      for (var prop in type.prototype) {
        var m = null;
        try {
          m = type.prototype[prop];
        } catch (e) {
          // As we are creating spys for abstract classes,
          // these classes might have getters that throw when they are accessed.
          // As we are only auto creating spys for methods, this
          // should not matter.
        }
        if (typeof m === 'function') {
          this.spy(prop);
        }
      }
    }
  }

  spy(name) {
    if (!this[name]) {
      this[name] = this._createGuinnessCompatibleSpy(name);
    }
    return this[name];
  }

  prop(name, value) { this[name] = value; }

  /** @internal */
  _createGuinnessCompatibleSpy(name): GuinessCompatibleSpy {
    var newSpy: GuinessCompatibleSpy = <any>jasmine.createSpy(name);
    newSpy.andCallFake = <any>newSpy.and.callFake;
    newSpy.andReturn = <any>newSpy.and.returnValue;
    newSpy.reset = <any>newSpy.calls.reset;
    // revisit return null here (previously needed for rtts_assert).
    newSpy.and.returnValue(null);
    return newSpy;
  }
}


Alongside, create routes.ts to mock Angular's RouteSegment and passing parameters between components.

import { RouteSegment } from '@angular/router';

export class MockRouteSegment implements RouteSegment {
  urlSegments:any;
  parameters:any;
  outlet:string;
  _type:any;
  _componentFactory:any;
  type:any;
  stringifiedUrlSegments:string;

  constructor(parameters?:{ [key:string]:any; }) {
    this.parameters = parameters;
  }

  getParam(param:string) {
    return this.parameters[param];
  }
}


With mocks in place, you can create a spec for SearchComponent that uses these as providers. Create a file at src/search/components/search.component.spec.ts and populate it with the following code:

import { provide } from '@angular/core';
import { TestComponentBuilder } from '@angular/compiler/testing';
import {
  it,
  describe,
  expect,
  inject,
  beforeEachProviders,
} from '@angular/core/testing';

import { RouteSegment } from '@angular/router';
import { MockRouteSegment } from '../shared/search/mocks/routes';
import { MockSearchService } from '../shared/search/mocks/search.service';

import { SearchComponent } from './search.component';

export function main() {
  describe('Search component', () => {
    var mockSearchService:MockSearchService;

    beforeEachProviders(() => {
      mockSearchService = new MockSearchService();

      return [
        mockSearchService.getProviders(),
        provide(RouteSegment, { useValue: new MockRouteSegment({ 'term': 'peyton' }) })
      ];
    });
  });
}


Add two tests, one to verify a search term is used when it's set on the component and a second to verify search is called when a term is passed in as a route parameter.

it('should search when a term is set and search() is called', inject([TestComponentBuilder], (tcb:TestComponentBuilder) => {
  return tcb.createAsync(SearchComponent).then((fixture) => {
    let searchComponent = fixture.debugElement.componentInstance;
    searchComponent.query = 'M';
    searchComponent.search();
    expect(mockSearchService.searchSpy).toHaveBeenCalledWith('M');
  });
}));

it('should search automatically when a term is on the URL', inject([TestComponentBuilder], (tcb:TestComponentBuilder) => {
  return tcb.createAsync(SearchComponent).then((fixture) => {
    fixture.detectChanges();
    expect(mockSearchService.searchSpy).toHaveBeenCalledWith('peyton');
  });
}));


Add a spec for the EditComponent as well, verifying fetching a single record works. Notice how you can access the component directly with fixture.debugElement.componentInstance, or its rendered version with fixture.debugElement.nativeElement. Create a file at src/search/components/edit.component.spec.ts and populate it with the code below:

import { provide } from '@angular/core';
import { TestComponentBuilder } from '@angular/compiler/testing';
import {
  it,
  describe,
  expect,
  inject,
  beforeEachProviders,
} from '@angular/core/testing';

import { RouteSegment } from '@angular/router';
import { ROUTER_FAKE_PROVIDERS } from '@angular/router/testing';
import { MockRouteSegment } from '../shared/search/mocks/routes';
import { MockSearchService } from '../shared/search/mocks/search.service';

import { EditComponent } from './edit.component';

export function main() {
  describe('Edit component', () => {
    var mockSearchService:MockSearchService;

    beforeEachProviders(() => {
      mockSearchService = new MockSearchService();

      return [
        mockSearchService.getProviders(),
        ROUTER_FAKE_PROVIDERS,
        provide(RouteSegment, { useValue: new MockRouteSegment({ 'id': '1' }) })
      ];
    });

    it('should fetch a single record', inject([TestComponentBuilder], (tcb:TestComponentBuilder) => {
      return tcb.createAsync(EditComponent).then((fixture) => {
        let person = {name: 'Emmanuel Sanders', address: {city: 'Denver'}};
        mockSearchService.setResponse(person);

        fixture.detectChanges();
        // verify service was called
        expect(mockSearchService.getByIdSpy).toHaveBeenCalledWith(1);

        // verify data was set on component when initialized
        let editComponent = fixture.debugElement.componentInstance;
        expect(editComponent.editAddress.city).toBe('Denver');

        // verify HTML renders as expected
        var compiled = fixture.debugElement.nativeElement;
        expect(compiled.querySelector('h3')).toHaveText('Emmanuel Sanders');
      });
    }));
  });
}


You should see "✔ 22 tests completed" in the shell window that's running npm run karma.start. If you don't, try canceling the command and restarting.

Integration Test the Search UI

To test if the application works end-to-end, you can write tests with Protractor. These are also known as integration tests, since they test the integration between all layers of your application.

To verify end-to-end tests work in the project before you begin, run the following commands in three different console windows.

# npm run webdriver-update <- You will need to run this the first time
npm run webdriver-start
npm run serve.e2e
npm run e2e


You should receive an error stating that the "nav text for About" is incorrect.

Image title

This happens because we added a Search link to the navbar and didn't update the test (in app.component.e2e.ts) that looks for the last child.

it('should have correct nav text for About', () => {
    expect(element(by.css('sd-app sd-navbar nav a:last-child')).getText()).toEqual('ABOUT');
});


Replace this test with the one below, and add a new one to verify the Search link is last.

it('should have correct nav text for About', () => {
  expect(element(by.css('sd-app sd-navbar nav a:nth-child(2)')).getText()).toEqual('ABOUT');
});

it('should have correct nav text for Search', () => {
  expect(element(by.css('sd-app sd-navbar nav a:last-child')).getText()).toEqual('SEARCH');
});


Now when you run npm run e2e, all specs should pass.

Testing the search feature

Create a new search.component.e2e-spec.ts spec in the same directory as your SearchComponent. Add tests to verify elements are rendered correctly and search works. At the time of this writing, Protractor's by.model and by.repeater don't work with Angular 2. For this reason, I used by.css to verify the HTML renders as expected.

describe('Search', () => {

  beforeEach(() => {
    browser.get('/search');
  });

  it('should have an input and search button', () => {
    expect(element(by.css('sd-app sd-search form input')).isPresent()).toEqual(true);
    expect(element(by.css('sd-app sd-search form button')).isPresent()).toEqual(true);
  });

  it('should allow searching', () => {
    let searchButton = element(by.css('button'));
    let searchBox = element(by.css('input'));
    searchBox.sendKeys('M');
    searchButton.click().then(() => {
      // doesn't work as expected - results in 0
      //expect(element.all(by.repeater('person of searchResults')).count()).toEqual(3);
      var list = element.all(by.css('sd-search table tbody tr'));
      expect(list.count()).toBe(3);
    });
  });
});


Testing the Edit Feature

Create a edit.component.e2e-spec.ts spec to verify the EditComponent renders a person's information and that you can update their information.

describe('Edit', () => {

  beforeEach(() => {
    browser.get('/edit/1');
  });

  let name = element(by.id('name'));
  let street = element(by.id('street'));
  let city = element(by.id('city'));

  it('should allow viewing a person', () => {
    expect(element(by.css('h3')).getText()).toEqual('Peyton Manning');
    expect(name.getAttribute('value')).toEqual('Peyton Manning');
    expect(street.getAttribute('value')).toEqual('1234 Main Street');
    expect(city.getAttribute('value')).toEqual('Greenwood Village');
  });

  it('should allow updating a name', function () {
    let save = element(by.id('save'));
    // send individual characters since sendKeys passes partial values sometimes
    // https://github.com/angular/protractor/issues/698
    ' Won!'.split('').forEach((c) => name.sendKeys(c));
    save.click();
    // verify one element matched this change
    var list = element.all(by.css('sd-search table tbody tr'));
    expect(list.count()).toBe(1);
  });
});


Run npm run e2e to verify all your end-to-end tests pass. You might receive a failure for the "Home" test.

Image title

If you do, open src/client/app/+home/home.component.e2e-spec.ts and change line 17 from this:

element(by.css('sd-home form input')).sendKeys('Tim Berners-Lee');


To this:

let input = element(by.css('sd-home form input'));
'Tim Berners-Lee'.split('').forEach((c) => input.sendKeys(c));


Run npm run e2e again. You should see a success message similar to the one below in your terminal window.

Image titleIf you made it this far and have all 13 specs passing — congratulations! You're well on your way to writing quality code with Angular 2 and verifying it works.

Continuous Integration

The angular2-seed project ships with a .travis.yml that you can use to run continuous integration for this application through Travis CI. To enable builds on Travis CI, login and enable builds for the GitHub repo you created the project in. Then trigger your first build with a git push.

When I first tried this, I received a failure because Protractor on Travis CI is unable to navigate directly to the search and edit components. I was able to work around this by modifying search.component.e2e-spec.ts to start at the top and navigate to the component.

beforeEach(() => {
  browser.get('/');
  element(by.linkText('SEARCH')).click();
});


I did something similar withedit.component.e2e-spec.ts:

beforeEach(() => {
  browser.get('/');
  element(by.linkText('SEARCH')).click();
  let search = element(by.css('sd-search form input'));
  'Man'.split('').forEach((c) => search.sendKeys(c));
  element(by.css('sd-search form button')).click();
  element(by.linkText('Peyton Manning')).click();
});


After making these changes, all e2e tests passed in Travis CI.

Source Code

A completed project with this code in it is available on GitHub at https://github.com/mraible/angular2-tutorial. If you have ideas for improvements, please leave a comment or send a pull request.

I wrote this tutorial in Asciidoctor so you can also read this tutorial on GitHub or using DocGist.

Summary

I hope you've enjoyed this quick-and-easy tutorial on testing Angular 2.0 RC1 applications. You can see the test coverage of your project by running npm run serve.coverage. You'll notice that the new components and service could use some additional coverage. I'll leave that as a task for the reader.

Image title

I learned a lot about testing from ng-book 2 and its Testing chapter. If you have any Angular 2 testing tips and tricks you'd like to share, I'd love to hear about them.

Analysts agree that a mix of emulators/simulators and real devices are necessary to optimize your mobile app testing - learn more in this white paper, brought to you in partnership with Sauce Labs.

Topics:
angular ,angular 2.0 ,rc1 ,node js ,applications

Published at DZone with permission of Matt Raible, DZone MVB. See the original article here.

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