public async Task AddCoinToWalletTest() { // Arrange var repo = new InMemoryRepository(); var walletId = new Guid("dd9fbf9b-a500-4c00-b00d-069ea4080004"); var coin = new Coin() { Id = Guid.NewGuid(), CreationDate = DateTime.Now }; // Act var updateResult = await repo.AddCoinToWallet(walletId, coin); // Assert Assert.NotNull(updateResult); Assert.IsType(typeof(Wallet), updateResult); }