public async Task ShowAllDecks() { var cards = new Card[] { new Card { Value = 0, Description = "zero" }, new Card { Value = 1, Description = "one" }, new Card { Value = 2, Description = "two" }, new Card { Value = 4, Description = "four" } }; var newDeck = new Deck { Name = "testDeck" }; var newDeck2 = new Deck { Name = "testDeck2" }; db.Decks.AddRange(newDeck, newDeck2); await db.SaveChangesAsync(); foreach (Card card in cards) { db.Cards.Add(card); newDeck2.Cards.Add(card); newDeck.Cards.Add(card); } await db.SaveChangesAsync(); var result = await deck.ShowAll(); var length = result.Count; Assert.That(2, Is.EqualTo(length)); }