AngularJS: Mock Controller Service

I am trying to mock a service for a controller but struggling to get it to work.

Using semi-psudeo code I have a service:

.factory('SomeService', ['$http'function($http) {

    var someService = {};

    someService.getData=function(val1, val2){
        ...
        return someData;
    }

    return someService;
}

And a controller like so:

 .controller('someController', ['SomeService', function(SomeService){
    var self = this;
    var data = [];

    self.getSomeData = = function(){
         var response = SomeService.getSomething.then(function(response){
              self.data = response;
         });
    };
 }]);

I am trying to write a test that uses a $provide to mock the service. Something like this:

var mockService

beforeEach(module(function($provide){
    mockService.getSomething = function(){ 

            return   [ ....];
    };

    $provide.value('SomeService', mockService);

}));

After injecting this mock and running the test I get:

Typeerror: cannot set property getSomething of undefined

Is there anything obviously wrong with this code (or right)?