Testing AngularJs' $http.defaults.headers.common if specific header is set - angularjs

Question

So I'm new to the world of JavaScript and AngularJS and therefor my code is not as good as it should be yet, but it's improving. Nevertheless I started learning and implementing a simple login page with a REST Backend. After the Login-Form is submitted, a authentication-token is returned and set as a default http-header property like this
$http.defaults.headers.common['X-AUTH-TOKEN'] = data.authToken;
This works fine whenever I test it manually, but that's not the way to go so I'd like to implement a unit-test which checks if the X-AUTH-TOKEN header is set.
Is there a way to check that with $httpBackend? e.g I have the following test:
describe('LoginController', function () {
var scope, ctrl, $httpBackend;
// Load our app module definition before each test.
beforeEach(module('myApp'));
// The injector ignores leading and trailing underscores here (i.e. _$httpBackend_).
// This allows us to inject a service but then attach it to a variable
// with the same name as the service.
beforeEach(inject(function (_$httpBackend_, $rootScope, $controller) {
$httpBackend = _$httpBackend_;
scope = $rootScope.$new();
ctrl = $controller('LoginController', {$scope: scope}, {$http: $httpBackend}, {$location: null});
}));
it('should create an authToken and set it', function () {
$httpBackend.expectPOST('http://localhost:9000/login', '200').respond(200, '{"authToken":"52d29fd63004c92b972f6b99;65e922bc-5e33-4bdb-9d52-46fc352189fe"}');
scope.login('200');
$httpBackend.flush();
expect(scope.data.authToken).toBe('52d29fd63004c92b972f6b99;65e922bc-5e33-4bdb-9d52-46fc352189fe');
expect(scope.loginValidationOverallError).toBe(false);
expect(scope.status).toBe(200);
});
My Controller looks like this:
.controller('LoginController', ['$scope', '$http', '$location',
function ($scope, $http, $location) {
// Login Stuff
$scope.data = {};
$scope.status = {};
$scope.loginValidationOverallError = false;
$scope.login = function (user) {
$http.post('http://localhost:9000/login', user).success(function (data, status) {
$scope.data = data;
$scope.status = status;
$scope.loginValidationOverallError = false;
console.log($scope.status, $scope.data);
$http.defaults.headers.common['X-AUTH-TOKEN'] = data.authToken;
$location.path('/user');
}).error(function (data, status) {
console.log(status + ' error');
$scope.loginValidationOverallError = true;
});
};
...
I checked the documentation at http://docs.angularjs.org/api/ngMock.$httpBackend but am not sure if the last test is actually applicable to my code (and how that code actually tests something)
it('should send auth header', function() {
var controller = createController();
$httpBackend.flush();
$httpBackend.expectPOST('/add-msg.py', undefined, function(headers) {
// check if the header was send, if it wasn't the expectation won't
// match the request and the test will fail
return headers['Authorization'] == 'xxx';
}).respond(201, '');
$rootScope.saveMessage('whatever');
$httpBackend.flush();
});

Answer 1

I was facing the same issue and I finally solved it. It was very tricky
Souce code for AuthenticationService.login() function
$http.post(...)
.success(function(data) {
...
$http.defaults.headers.common['Authorization'] = data.oauth_token;
});
Test code
beforeEach(inject(function(_$httpBackend_,AuthenticationService) {
$httpBackend = _$httpBackend_;
$authenticationService = AuthenticationService;
}));
it('should login successfully with correct parameter', inject(function($http) {
// Given
...
...
var fakeResponse = {
access_token: 'myToken'
}
$httpBackend.expectPOST('oauth/token',urlEncodedParams, function(headers) {
return headers['Content-Type'] === 'application/x-www-form-urlencoded';
}).respond(200, fakeResponse);
// When
$authenticationService.login(username,password);
// Then
$httpBackend.flush();
expect($http.defaults.headers.common['Authorization']).toBe('myToken');
The trick here is that the default header is set on the real $http service, not the mocked $httpBackend. That's why you should inject the real $http service
I've tried testing the $httpBackend but got an "undefined" error because $httpBackend does not have 'defaults' property