public async Task UpdateTheEventsImageUrl() { const int eventId = 1; Context.Events.Add(new Event { Id = eventId }); await Context.SaveChangesAsync(); var message = new UpdateEventImageUrl { EventId = eventId, ImageUrl = "ImageUrl" }; var sut = new UpdateEventImageUrlHandler(Context); await sut.Handle(message); var result = Context.Events.Single(x => x.Id == eventId); Assert.Equal(result.ImageUrl, message.ImageUrl); }