fix(cookieReader): safely access $document so it can be mocked

[shahata]

Closes #11373

[shahata]

I'm really not sure that this is the right way to solve this. I'm thinking it might be a good idea to have some mock implementation of cookieReader/cookieWriter in angular-mocks which can be configured during tests similarly to $httpBackend. We used to have something similar in $browser, but it wasn't documented and it got refactored out during the ngCookies re-write (which is why this problem only occurred now)

[Narretz]

@petebacondarwin probably comes up with a good idea how to solve this, he always does :)

[petebacondarwin]

I think this is probably overkill. If the developer mocks out window and doesn't include a document then lots of stuff is going to break. Instead, how about we simply do

lastCookieString = rawDocument.cookie || '';

In the function below.

[shahata]

actually this is the only place that breaks, you can mock out $window and not include $document. See https://github.com/angular/angular.js/blob/master/test/ng/windowSpec.js

[shahata]

I can also do something like this, if you prefer:

rawDocument = $document[0] || {};
lastCookieString = rawDocument.cookie || '';

[petebacondarwin]

Ugh! Mocking window without a document is surely crazy juice!
OK let's go with this version:

rawDocument = $document[0] || {};
lastCookieString = rawDocument.cookie || '';

[shahata]

okay, amended.

[petebacondarwin]

LGTM - feel free to merge