Is this approach correct when testing an Angular controller?

I'd like someone to review these tests to make sure I'm along the right lines in Angular testing.

Note - They do all pass (great) but I feel like I'm struggling to understand the finer points of Angular testing.

Any thoughts?

var headerControllers = angular.module('header.controllers', []);
headerControllers.controller('headerController', ['$scope', 'headerService', function($scope, headerService){

this.headerService = headerService;
this.headerTitle = headerService.headerTitle;
this.show = false;

$scope.$watch('header.headerService.headerTitle', function (newVal, oldVal, scope) {
    if(newVal) {
        $scope.header.headerTitle = headerService.headerTitle;
        $scope.header.show = true;
    } else {
        $scope.header.show = false;
    }
});
$scope.header = this;
}]);

Above is the controller to be tested and below are the tests:

describe( "Unit Test:  Header Bar Controller", function() {

var scope, headerService, headerBarController;
var title = "Test header title";

beforeEach( module('Header.controllers'));
beforeEach( module('Header.services') );
beforeEach( inject( function( $injector, $rootScope, $controller, _headerService_ ) {

    scope = $rootScope.$new();

    headerService = $injector.get( 'headerService' );
    headerService.setTitle( title );

    headerBarController = $controller( 'HeaderController',
    {
       $scope: scope,
       headerService: headerService
    }); 

}));

it( "should have the controller defined", function() {
    expect( headerBarController ).not.toBe( undefined );   
});

it( "should receive and load the header-service", function() {
    expect( headerService ).not.toBe( undefined );
    expect( headerBarController.headerService ).toBe( headerService );
});

it( "should have a header title set to the value received from the header-service", function() {
    expect( headerBarController.headerTitle ).toBe( title );
});

it( "should have an initial show value of false", function() {
    expect( headerBarController.show ).toBe( false );
});

it( "should set the header object show value to true when the title is changed", function() {

    headerService.headerTitle = title;
    scope.$apply();

    expect( scope.header.show ).toBe( true );
});  

it( "should have header object show value of false if title is not set", function() {

    expect( scope.header.show ).toBe( false );
});

});