Angularjs - Unit testing introduction

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A presentation made for the AngularJS-IL meetup group that took place in May 2014 at Google TLV Campus. its a demonstration of Unit testing an AngularJS component with jasmine and karma.

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Angularjs - Unit testing introduction

  1. 1. Unit Testing in Practice
  2. 2. nirkaufman@gmail.com Download the reference project at: https://github.com/nirkaufman/angularjs-unit-testing-demo contact me at: nirkaufman@gmail.com or http://www.linkedin.com/in/nirkaufman
  3. 3. nirkaufman@gmail.com Getting Started with Unit Testing Intruduction
  4. 4. nirkaufman@gmail.com About Unit Testing The primary goal of unit testing is to take the smallest piece of testable software in the application, isolate it from the remainder of the code, and determine whether it behaves exactly as you expect.
  5. 5. nirkaufman@gmail.com Testing AngularJS App`s AngularJS build around the concept of dependency injection & loose coupling to the DOM which make it a very tesable.
  6. 6. nirkaufman@gmail.com Test Driven Developemnt a software development process that relies on the repetition of a very short development cycle: first the developer writes an (initially failing) automated test case that defines a desired improvement or new function, then produces the minimum amount of code to pass that test, and finally refactors the new code to acceptable standards.
  7. 7. nirkaufman@gmail.com RED (fail) Green (pass) REFACTO R 1. write a test that fails 2. write only enougth code to make it pass 3. improve code quality Test Driven Developemnt
  8. 8. nirkaufman@gmail.com The main goal for Karma is to bring a productive testing environment to developers. The environment being one where they don't have to set up loads of configurations, but rather a place where developers can just write the code and get instant feedback from their tests. Because getting quick feedback is what makes you productive and creative. http://karma-runner.github.io/
  9. 9. nirkaufman@gmail.com Jasmine is a behavior-driven development framework for testing JavaScript code. It does not depend on any other JavaScript frameworks. It does not require a DOM. And it has a clean, obvious syntax so that you can easily write tests. http://jasmine.github.io/
  10. 10. nirkaufman@gmail.com Setting up our TDD Enveirment Project Setup
  11. 11. nirkaufman@gmail.com Let`s start from scratch. First, we need to create a basic project structure with a folder that contain our sources, and a folder that contains our specs. then we can init a package.json $ npm init
  12. 12. nirkaufman@gmail.com $ npm install karma let`s install Karma (and all the plugins your project needs) locally in the project's directory. (don`t forget to use the --save-dev flags)
  13. 13. nirkaufman@gmail.com $ npm install karma-jasmine $ npm install karma-chrome-launcher since we going to use jasmine, let`s install tha karma adaptor plugin for jasmine. we will also install the chrome launcher plugin to enable karma to launch chrome browser fo us
  14. 14. nirkaufman@gmail.com $ npm install -g karma-cli Finally, we will install the karma command line interface (cli) globally, which enable us to easily configure karma in our project
  15. 15. nirkaufman@gmail.com $ karma init with the karma cli installed, we can create our configuration file fast and easy.
  16. 16. nirkaufman@gmail.com $ karma start $ karma run Let`s take karma for a test drive: in webstorm, right click on the configuration file and choose run. if you don`t use webstorm, start the karma server with start, and run you tests with run
  17. 17. nirkaufman@gmail.com quick intruduction to the Jasmine framwork Jasmine 101
  18. 18. nirkaufman@gmail.com describe("suite name", function() { it("contains spec with an expectation", function() { expect(true).toBe(true); }); }); in jasmine, we begin by creating a test suite with the global describe function that wrap our specs. specs are defined by the global function it. inside the spec we can describe our expextations by using tha expect function chained to a matcher function
  19. 19. nirkaufman@gmail.com describe("suite name", function() { beforeEach(function () {//excute before each spec}) it("contains spec with an expectation", function() { expect(true).toBe(true); }); afterEach(function () {//excute after each spec}) }); we can run code before and after each spec in a suite block using the beforeEach and afterEach functions
  20. 20. nirkaufman@gmail.com // spy on the method setBar of foo object spyOn(foo, 'setBar'); it("contains spec with an expectation", function() { expect(foo.setBar).toHaveBeenCalled(); expect(foo.setBar).toHaveBeenCalledWith(32); }); }); jasmine use spies to track calls to a function with all it`s arguments. There are special matchers for interacting with spies. The toHaveBeenCalled and The toHaveBeenCalledWith
  21. 21. nirkaufman@gmail.com Test Driven Development in practice Testing AngularJS
  22. 22. nirkaufman@gmail.com $ bower install angular $ bower install angular-mocks We are going to develop a small Task Manger app. in the process we will learn how to unit test the building blocks of every AngularJS application: controllers, services, directives, events & http requests. First, let`s get some resources using bower
  23. 23. nirkaufman@gmail.com Controllers
  24. 24. nirkaufman@gmail.com // get the module that contain the controller beforeEach(module('todolist')); // inject the $controller and the rootScope beforeEach(inject(function ($rootScope, $controller) { // create a fresh new scope for the controller scope = $rootScope.$new(); // create a controller with this scope ctrl = $controller('TodoListController',{$scope: scope}); })); In order to test controllers we need to holds an instance of the controller, initialize a scope for it and testing our expectations against that scope.
  25. 25. nirkaufman@gmail.com services Services
  26. 26. nirkaufman@gmail.com // get the module that contain the service beforeEach(module('todolist')); // inject the $injector beforeEach(inject(function ($injector) { // use the $injector to get a hold on the service service = $injector.get(‘ServiceName’); })); In order to test services we need to use the $injector to get an instance of the service
  27. 27. nirkaufman@gmail.com Directive
  28. 28. nirkaufman@gmail.com // get the module that contain the service beforeEach(module('todolist')); // inject the $compile service and the $rootScope beforeEach(inject(function ($compile, $rootScope) { // use the $rootScope to create a scope for the directive scope = $rootScope; // create an angular element from a HTML string element = angular.element(‘<div my-directive ></div>’) // compile the element with the scope $compile(element)(scope) scope.$apply() })); In order to test a directive, we need to create an element that will host the directive and compile it with a scope. in our spec, we need trigger the digest.
  29. 29. nirkaufman@gmail.com http requests
  30. 30. nirkaufman@gmail.com // inject the $httpBackend service and the $rootScope beforeEach(inject(function ($httpBackend) { // use the $rootScope to create a scope for the directive httpBackend = $httpBackend; it("somting that make a request", function() { // expect a request httpBackend.expectGET(‘api’).respond(200); // code that make a request httpBackend.flush(); // do`nt forget to flush.. }); })); the $httpBackend is a fake HTTP Back-end implementaion. in the most basic use we can verify that a request is made & stub responses
  31. 31. nirkaufman@gmail.com Productive Tips Making testing even more easier
  32. 32. nirkaufman@gmail.com When the number of test suites and specs grows larger, the overall test speed is affected. jasmine include some usfull syntax to control it. // run this usite ddescribe() // run this spec iit() // run this spec xit() webstorm users can install the ddescriber for jasmine
  33. 33. nirkaufman@gmail.com in webstorm the run panel enable us some more featuers like: Set Auto Test Delay Time Export Test Results Filter and sort Run / Debug Configuration live templates
  34. 34. nirkaufman@gmail.com Thank You! Download the reference project at: https://github.com/nirkaufman/angularjs-unit-testing-demo contact me at: nirkaufman@gmail.com or http://www.linkedin.com/in/nirkaufman

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