public async Task CreateForTripShoudIncreaseCommentsCount()
{
var list = new List <Comment>();
var mockRepo = new Mock <IDeletableEntityRepository <Comment> >();
mockRepo.Setup(x => x.All()).Returns(() => list.AsQueryable());
mockRepo.Setup(x => x.AddAsync(It.IsAny <Comment>())).Callback((Comment comment) => list.Add(comment));
var service = new CommentService(mockRepo.Object);
await service.CreateForTrip(1, "ааа", "1");
await service.CreateForTrip(1, "ббб", "1");
Assert.Equal(2, list.Count());
}