Does the karma/jasmine test instantiate and run the controller first? - jasmine

Question

This is my test:
describe('Controller: driversController', function () {
// First, we load the app's module
beforeEach(module('F1FeederApp'));
// Then we create some variables we're going to use
var driversController, scope;
beforeEach(inject(function ($controller, $rootScope, $httpBackend) {
// Here, we create a mock scope variable, to replace the actual $scope variable the controller would take as parameter
scope = $rootScope.$new();
// Then we create an $httpBackend instance. I'll talk about it below.
httpMock = $httpBackend;
// Here, we set the httpBackend standard reponse to the URL the controller is supposed to retrieve from the API
httpMock.expectJSONP("http://ergast.com/api/f1/2013/driverStandings.json?callback=JSON_CALLBACK").respond(
{"MRData": {"StandingsTable": {"StandingsLists" : [{"DriverStandings":[
{
"Driver": {
"givenName": 'Sebastian',
"familyName": 'Vettel'
},
"points": "397",
"nationality": "German",
"Constructors": [
{"name": "Red Bull"}
]
},
{
"Driver": {
"givenName": 'Fernando',
"familyName": 'Alonso'
},
"points": "242",
"nationality": "Spanish",
"Constructors": [
{"name": "Ferrari"}
]
},
{
"Driver": {
"givenName": 'Mark',
"familyName": 'Webber'
},
"points": "199",
"nationality": "Australian",
"Constructors": [
{"name": "Red Bull"}
]
}
]}]}}}
);
// Here, we actually initialize our controller, passing our new mock scope as parameter
driversController = $controller('driversController', {
$scope: scope
});
// Then we flush the httpBackend to resolve the fake http call
httpMock.flush();
}));
// Now, for the actual test, let's check if the driversList is actually retrieving the mock driver array
it('should return a list with three drivers', function () {
expect(scope.driversList.length).toBe(3);
});
// Let's also make a second test checking if the drivers attributes match against the expected values
it('should retrieve the family names of the drivers', function () {
expect(scope.driversList[0].Driver.familyName).toBe("Vettel");
expect(scope.driversList[1].Driver.familyName).toBe("Alonso");
expect(scope.driversList[2].Driver.familyName).toBe("Webber");
});
});
Questions:
In my first test, I write:
expect(scope.driversList.length).toBe(3);
This scope variable doesn't get set until this method in my controller fires:
angular.module('F1FeederApp.controllers', []).
/* Drivers controller */
controller('driversController', function($scope, ergastAPIservice) {
$scope.nameFilter = null;
$scope.driversList = [];
$scope.searchFilter = function (driver) {
var re = new RegExp($scope.nameFilter, 'i');
return !$scope.nameFilter || re.test(driver.Driver.givenName) || re.test(driver.Driver.familyName);
};
ergastAPIservice.getDrivers().success(function (response) {
//Digging into the response to get the relevant data
$scope.driversList = response.MRData.StandingsTable.StandingsLists[0].DriverStandings;
});
}).
So is my controller really a function that gets called automatically in my test? How? When does it get called?
Why are we using $rootScope here in the test?

Answer 1

For every test suite controller gets initialize first along with the beforeEach settings (if any).
Coming to your questions
1. Since controller is initialize and your below method is not wrapped inside any function it is been called and sets your driverList array
ergastAPIservice.getDrivers().success(function (response) {
//Digging into the response to get the relevant data
$scope.driversList = response.MRData.StandingsTable.StandingsLists[0].DriverStandings;
});
To avoid simply wrap it inside a function. To call this function on controller load you can use
ng-init
You can check this