injectでテスト対象を取得する前に$provideを使ってモックを登録しておく．
describe("HowToMock$Window", function(){
beforeEach(function(){
// we need to setup $window mock before inject()
mock(function($provide){
$provide.factory("$window", function(){
var $window = {};
return $window;
});
});
// get service/controller which depends on $window
inject(function(someService){
});
});
});