angularjs - how to test inner controller which loads data for select control in angular-formly -

i have ui-select field

{   key: 'data_id',   type: 'ui-select',   templateoptions: {     required: true,     label: 'select label',     options: [],     valueprop: 'id',     labelprop: 'name'   },   controller: function($scope, dataservice) {     dataservice.getselectdata().then(function(response) {       $scope.to.options = response.data;     });   } } 

how can access inner controller in unit tests , check data loading select field works ?

update: example of test such:

var initializepagecontroller = function() {   return $controller('pagectrl', {     '$state': $state,     '$stateparams': $stateparams   }); };  var initializeselectcontroller = function(selectelement) {   return $controller(selectelement.controller, {     '$scope': $scope   }); }; 

then test case looks like:

it('should able list of data....', function() {    $scope.to = {};    var vm = initializepagecontroller();     $httpbackend.expectget(/\/api\/v1\/data...../).respond([      {id: 1, name: 'data 1'},      {id: 2, name: 'data 2'}    ]);     initializeselectcontroller(vm.fields[1]);    $httpbackend.flush();     expect($scope.to.options.length).to.equal(2); }); 

you few ways. 1 option test controller contains configuration. so, if have field configuration set $scope.fields so:

$scope.fields = [ { /* field config have above */ } ]; 

then in test like:

$controller($scope.fields[0].controller, { mockscope, mockdataservice }); 

then assertions.