Jasmine: Create spy on window objects that don't exist

Question

I'm building a cordova / phonegap app along with AngularJS. In my app, I'm using some native plugins from cordova, like the geolocation plugin.

During my tests, this plugins aren't available (because phonegap isn't present), $window.plugins returns undefined in my tests. And of course, $window.plugins.anotherPlugin also fails.

Therefore, I have to mock out this parts for my tests. Currently, I'm doing it this way

  beforeEach(function() {
    $window.plugins = {
      anotherPlugin: {
        foo: function() {}
      }
    };
  });

But what if in the future, another library uses the $window.plugins namespace, and I'm overwriting it in my tests? This would break other tests. With the way above, I would have to do some cleanup after my tests, to ensure that the old values of $window.plugins are set back. I think, this way isn't very clean, and I wonder if there is a better way to do this with jasmine.

So my question is: How can I spy on $window.plugins.anotherPlugin by creating dummy functions with jasmine, without affecting other tests, when $window.plugins doesn't exist?

Answer 1

You should load the module of the part you want to test and generate a mock module, which provides the spies.

beforeEach(function () {
    module('ModuleUnderTest', function($provide) {
        var windowMock = {
            plugins: {
                anotherPlugin: jasmine.createSpyObj('anotherPlugin', ['foo', 'bar'])
            }
        };

        // substitute all dependencies with mocks
        $provide.value('$window', windowMock);
    });
});

Beware, I have not tested the code, but you should get the gist.