How do I test a .run in AngularJS?

Question

myApp.run([
  '$rootScope', 'userService', function($rootScope, userService) {
    return userService.isAuthenticated().then(function(response) {
      if (response.data.authenticated) {
        return $rootScope.$broadcast('login', response.data);
      } else {
        return userService.logout();
      }
    });
  }
]);

That's my code that I have in an init.js file. How can I unit test this?

Answer 1

Unit testing a run(..) block is as simple as loading your module(..) in jasmine.

All of the code below is available in this plunker.

Consider the following very simple app.js:

var _idx = 1;
window.log = function(s) {
  console.log('(' + _idx++ + ') ' + s);
};

var app = angular.module('myapp', []);

app.run(function($rootScope) {
  log('run block');
  $rootScope.valueSetInRun = 666;

});

app.controller('MainCtrl', function($scope) {
  log('MainCtrl block');
});

Note that the markup is irrelevant in this app.

Now consider the following test:

describe('myapp', function() {

  beforeEach(module('myapp'));

  beforeEach(inject(function($rootScope) {
    log('beforeEach');
  }));

  it('should allow me to test the run() block', inject(function ($rootScope) {
    log('it block');
    expect( $rootScope.valueSetInRun ).toBe(666);
  }));
});

Here is the console output:

(1) run block 
(2) MainCtrl block 
(3) run block 
(4) beforeEach 
(5) it block 

Note that the test passes

Some important observations

• The first two console outputs, (1) and (2) are logged during normal app execution
• Log messages (3) to (5) are outputted while the test is running.

---

Given the above, we can conclude the following:

1. In the unit test, the module 'myapp' was instantiated
2. In the unit test, MainCtrl wasn't instantiated
3. In the unit test, the run block was executed
4. When running a unit test, the beforeEach...run block is executed first, then beforeEach and finally the it block.
5. The second beforeEach is not useful for unit testing a run block (note that you can put a beforeEach block before beforeEach(module('myapp'));, however if you try creating an injector in that block your test will fail)

And finally, we can conclude that the code above is how you can test a run block. As to your particular test, armed with this knowledge, it will be possible to construct a unit test using dependency injection mocking and Jasmine's toHaveBeenCalled() assertion.

Answer 2

One easy method would be to store an 'authentication' object in $rootScope. In your unit test, expect that value to be empty or undefined, then populate the object in your service, and re-test against the value or length of that object.