public void AccessToken_AddAnAccessToken_ShouldAddCorrectly() { var data = new List <AccessToken>().AsQueryable(); var mock = new Mock <DbSet <AccessToken> >(); var mockContext = new Mock <Models.Models.Database>(); mockContext.Setup(m => m.AccessTokens).Returns(mock.Object); AccessTokenService accTokService = new AccessTokenService(mockContext.Object); AccessToken accToken = new AccessToken() { Device = new Device() { Id = Guid.NewGuid(), LastRequestDateTime = DateTime.Now }, UniqueAccesToken = Guid.NewGuid().ToString("D"), CreatedDateTime = DateTime.Now }; accTokService.AddAccessToken(accToken); mock.Verify(m => m.Add(It.IsAny <AccessToken>()), Times.Once()); mockContext.Verify(m => m.SaveChanges(), Times.Once()); }