AngularJS. Unit Testing AngularJS Directives with Karma & Jasmine

Transcription

1 AngularJS Unit Testing AngularJS Directives with Karma & Jasmine

2 Directives Directives are different frm ther cmpnents they aren t used as bjects in the JavaScript cde They are used in HTML templates f the applicatin We write directives t perfrm DOM manipulatins we can t ignre them in unit tests as they play an imprtant rle They directly affect the usability f the applicatin Directives are the mst imprtant and mst cmplex cmpnents in AngularJS

3 Abut Testing Directives Testing directives is tricky They are nt called like a functin They are declaratively applied n the HTML template Their actins are executed when the template is cmpiled and a user interacts with the directive When perfrming unit tests We need t autmate the user actins We need t manually cmpile the HTML in rder t test the functinality f the directives

4 Set up Objects t test Directive Need t get references t bjects needed befre starting t test a directive The key bject t create is an element cntaining the directive t be tested We need t cmpile a piece f HTML with the directive specified in it t get the directive int actin On cmpilatin f the HTML, the lifecycle f the directive is kicked in

5 Directive life cycle In a directive s life cycle, there are fur distinct functins that can execute if they are defined Each enables the develper t cntrl and custmize the directive at different pints f the life cycle. The cmpile functin allws the directive t manipulate the DOM befre it is cmpiled and linked thereby allwing it t add/remve/change directives, as well as, add/remve/change ther DOM elements.

6 Directive life cycle (2) The cntrller functin facilitates directive cmmunicatin. Sibling and child directives can request the cntrller f their siblings and parents t cmmunicate infrmatin. The pre-link functin allws fr private $scpe manipulatin befre the pst-link prcess begins. The pst-link methd is the primary wrkhrse methd f the directive.

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8 Getting Ready t test Cmpile HTML Template cntaining directive Inject $cmpile service Use $cmpile service t manually cmpile HTML Cmpilatin triggers directive life cycle Initiate next digest cycle After next cycle, directive bject wuld be in the same state as it appears n a page Will want t initiate a digest cycle after making changes t the DOM r mdel

9 Things t test in Directive Testing Directive s Template Testing Link Functin DOM Manipulatin Watchers DOM Events Testing Directive s Scpe Testing Require Testing Replace

10 Setting up Karma install karma fr develpment purpses $ npm install --save-dev karma Install preprcessr t lad html templates $ npm install karma-ng-html2js-preprcessr --save-dev Install karma plug-ins t enable us t use Jasmine test framewrk and Ggle Chrme as target brwser $ npm install jasmine-cre karma-jasmine karma-chrme-launcher --save-dev

11 Cnfiguring Test Runner Create a cnfiguratin file fr the karma settings $ karma init karma.cnf.js Yu will be asked several questins Accept the defaults t as many as yu can Answer NO fr the RequireJS questin Will fill in the surce and test files sectin manually The cnfig file called karma.cnf.js will be created Will use cfig file t run run tests frm the terminal

12 angular-mcks t mck services Install angular-mcks t inject and mck Angular services int yur unit tests $ npm install angular-mcks --save-dev

13 Files sectin f cnfig file // list f files / patterns t lad in the brwser files: [ // Libraries 'nde_mdules/jquery/dist/jquery.min.js', 'nde_mdules/angular/angular.js', 'nde_mdules/angular-mcks/angular-mcks.js', 'nde_mdules/angular-rute/angular-rute.js', 'nde_mdules/angular-resurce/angular-resurce.js', 'nde_mdules/angular-messages/angular-messages.js', // Our app 'src/app.js', 'src/js/*.js', // tests 'tests/*spec.js', ], // Templates 'views/*.html'

14 Preprcessr sectin f cnfig file preprcessrs: { // Generate js files frm html templates 'views/*.html': 'ng-html2js' },

15 Running unit tests Start test runner by issuing fllwing cmmand $ karma start karma.cnf.js Expect tests t fail (nne written) & fix fixable errrs Optimizatin: update the package.jsn manifest with scripts sectin t run karma $ npm test

16 Scripts sectin f manifest "scripts": { }, "test": "karma start karma.cnf.js

17 Testing AngularJS directives Create a test suite with describe. The string parameter shuld include the name f the directive being tested. The functin parameter is the blck f cde that implements the suite Use befreeach t lad the mdule that cntains the directive being tested and the HTML templates. Inject the $cmpile and $rtscpe services in a befreeach blck That allws yu t create a new $scpe and access the $cmpile service. Cmpile an element cntaining the directive t be tested Initiate the digest cycle f the $scpe

18 Testing AngularJS directives (2) Nw that everything is setup, we can spec ut tests using the it functin. String parameter is title f spec r descriptin f what the spec is testing Functin parameter is the spec r test. Test functinality f cde that we write See slide entitled Things t test in Directive Each test shuld have 1 r mre expectatins Might be wise t fllw this testing paradigm: setup à run cde à assert

19 Examples Walk thrugh prcess f creating and running directive tests fr sample applicatin.

20 Resurces