//[ExpectedException]
public void UpdateTagNames_With_Empty_Tags()
{
var tagRepository = Substitute.For <ITopicTagRepository>();
var topicRepository = Substitute.For <ITopicRepository>();
var topicTagService = new TopicTagService(tagRepository, topicRepository);
const string oldName = "";
const string newName = "";
tagRepository.GetTagName(oldName).Returns(x => null);
topicTagService.UpdateTagNames(newName, oldName);
tagRepository.DidNotReceiveWithAnyArgs().Update(Arg.Is <TopicTag>(x => x.Tag == null));
}
public void UpdateTagNames_With_Non_Existing_Tag()
{
var tagRepository = Substitute.For <ITopicTagRepository>();
var topicRepository = Substitute.For <ITopicRepository>();
var topicTagService = new TopicTagService(tagRepository, topicRepository);
var oldName = "bilbo";
var newName = "baggins";
tagRepository.GetTagName(oldName).Returns(x => null);
topicTagService.UpdateTagNames(newName, oldName);
tagRepository.DidNotReceiveWithAnyArgs().Update(Arg.Is <TopicTag>(x => x.Tag == null));
}