public async Task It_writes_success_for_add_to_console() { var quantity = 6; var name = "Mountain Dew"; var shoppingList = new ShoppingList(); var console = new TestConsole(); await shoppingList.AddItemsAsync(console, name, quantity); console.Out.ToString().Should().Be($"Successfully added {quantity} '{name}' to the shopping list: {shoppingList.ListName}\n"); }