javascript - How to unit test an angularjs promise -

i unit test promise this:

 function getsongs() {     var d = $q.defer();     var url = 'http://localhost:3002/songs';      $http({       method: 'get',       url: url     })     .success(function(data) {       d.resolve(data);     })     .error(function(data) {       d.reject(data);     });      return d.promise;   } 

this returns , arrays of objects. used in controller calling getsongs function:

var vm = this;  vm.songlist = [];  vm.init = function () {   playerscreenservice.getsongs()     .then(getsongssuccess); };  vm.init(); 

thank much.

take @ $httpbackend. test this:

describe('playerscreenservice', function () {      it('should send http request', inject(function (playerscreenservice, $httpbackend) {         $httpbackend.whenget('http://localhost:3002/songs').respond(200, {...});          var getsongssuccess = jasmine.createspy('getsongssuccess');         var getsongserror = jasmine.createspy('getsongserror');         playerscreenservice.getsongs()             .then(getsongssuccess, getsongserror);          $httpbackend.flush();         expect(getsongssuccess).tohavebeencalledwith({...});         expect(getsongserror).not.tohavebeencalled();     }));  });