Enable Nullable on XamarinCommunityToolkit

samples/XCT.Sample/Pages/Base/BasePage.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Threading.Tasks;
 using System.Windows.Input;
 using Xamarin.CommunityToolkit.ObjectModel;
 using Xamarin.CommunityToolkit.Sample.Models;
@@ -9,7 +10,13 @@ namespace Xamarin.CommunityToolkit.Sample.Pages
 	public class BasePage : ContentPage
 	{
 		public BasePage() =>
-			NavigateCommand = CommandFactory.Create<SectionModel>(sectionModel => Navigation.PushAsync(PreparePage(sectionModel)));
+			NavigateCommand = CommandFactory.Create<SectionModel>(sectionModel =>
+			{
+				if (sectionModel != null)
+					return Navigation.PushAsync(PreparePage(sectionModel));
+
+				return Task.CompletedTask;
+			});
 
 		public Color DetailColor { get; set; }
 

samples/XCT.Sample/Pages/TestCases/MediaElementSourcePage.xaml.cs

@@ -12,6 +12,6 @@ class MediaElementViewModel : BindableObject
 	{
 		public string VideoAsString { get; set; } = "https://tipcalculator.appwithkiss.com/video/Hint_1_2_EN_12.mov";
 
-		public MediaSource VideoAsMediaSource => MediaSource.FromUri(VideoAsString);
+		public MediaSource? VideoAsMediaSource => MediaSource.FromUri(VideoAsString);
 	}
 }

samples/XCT.Sample/ViewModels/Converters/ItemSelectedEventArgsViewModel.cs

@@ -16,6 +16,6 @@ public class ItemSelectedEventArgsViewModel
 			};
 
 		public ICommand ItemSelectedCommand { get; } =
-			CommandFactory.Create<Person>(person => Application.Current.MainPage.DisplayAlert("Item Tapped: ", person.Name, "Cancelf"));
+			CommandFactory.Create<Person>(person => Application.Current.MainPage.DisplayAlert("Item Tapped: ", person?.Name, "Cancel"));
 	}
 }

samples/XCT.Sample/ViewModels/Converters/ItemTappedEventArgsViewModel.cs

@@ -15,7 +15,7 @@ public class ItemTappedEventArgsViewModel
 		};
 
 		public ICommand ItemTappedCommand { get; } =
-			CommandFactory.Create<Person>(person => Application.Current.MainPage.DisplayAlert("Item Tapped: ", person.Name, "Cancel"));
+			CommandFactory.Create<Person>(person => Application.Current.MainPage.DisplayAlert("Item Tapped: ", person?.Name, "Cancel"));
 	}
 
 	public class Person

samples/XCT.Sample/ViewModels/Views/PopupControlViewModel.cs

@@ -35,7 +35,7 @@ async void OnDisplayPopup(Type popupType)
 		{
 			var view = (VisualElement)Activator.CreateInstance(popupType);
 
-			if (view is Popup<string> popup)
+			if (view is Popup<string?> popup)
 			{
 				var result = await Navigation.ShowPopupAsync(popup);
 				await Application.Current.MainPage.DisplayAlert("Popup Result", result, "OKAY");

src/CommunityToolkit/Xamarin.CommunityToolkit.UnitTests/Converters/ByteArrayToImageSourceConverter_Tests.cs

@@ -22,7 +22,7 @@ public void ByteArrayToImageSourceConverter()
 
 			var result = byteArrayToImageSourceConverter.Convert(byteArray, typeof(ByteArrayToImageSourceConverter), null, CultureInfo.CurrentCulture);
 
-			Assert.True(StreamEquals(GetStreamFromImageSource((ImageSource)result), memoryStream));
+			Assert.True(StreamEquals(GetStreamFromImageSource((ImageSource?)result), memoryStream));
 		}
 
 		[Theory]
@@ -34,28 +34,32 @@ public void InvalidConverterValuesReturnsNull(object value)
 			Assert.Throws<ArgumentException>(() => byteArrayToImageSourceConverter.Convert(value, typeof(ByteArrayToImageSourceConverter), null, CultureInfo.CurrentCulture));
 		}
 
-		Stream GetStreamFromImageSource(ImageSource imageSource)
+		Stream? GetStreamFromImageSource(ImageSource? imageSource)
 		{
-			var streamImageSource = (StreamImageSource)imageSource;
+			var streamImageSource = (StreamImageSource?)imageSource;
 
 			var cancellationToken = System.Threading.CancellationToken.None;
-			var task = streamImageSource.Stream(cancellationToken);
-			return task.Result;
+			var task = streamImageSource?.Stream(cancellationToken);
+			return task?.Result;
 		}
 
-		bool StreamEquals(Stream a, Stream b)
+		bool StreamEquals(Stream? a, Stream? b)
 		{
 			if (a == b)
 				return true;
 
-			if (a == null ||
-				b == null ||
-				a.Length != b.Length)
+			if (a == null
+				|| b == null
+				|| a.Length != b.Length)
+			{
 				return false;
+			}
 
 			for (var i = 0; i < a.Length; i++)
+			{
 				if (a.ReadByte() != b.ReadByte())
 					return false;
+			}
 
 			return true;
 		}

src/CommunityToolkit/Xamarin.CommunityToolkit.UnitTests/Helpers/WeakEventManagerTests/DelegateWeakEventManager_Delegate_Tests.cs

@@ -58,7 +58,9 @@ void HandleDelegateTest(object sender, PropertyChangedEventArgs e)
 			}
 
 			// Act
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
 			propertyChangedWeakEventManager.RaiseEvent(null, new PropertyChangedEventArgs("Test"), nameof(PropertyChanged));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
 
 			// Assert
 			Assert.True(didEventFire);
@@ -173,7 +175,9 @@ public void WeakEventManagerDelegate_UnassignedEventManager()
 			void HandleDelegateTest(object sender, PropertyChangedEventArgs e) => didEventFire = true;
 
 			// Act
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
 			unassignedEventManager.RaiseEvent(null, null, nameof(PropertyChanged));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
 
 			// Assert
 			Assert.False(didEventFire);
@@ -205,9 +209,7 @@ public void WeakEventManagerDelegate_AddEventHandler_NullHandler()
 			// Act
 
 			// Assert
-#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference
 			Assert.Throws<ArgumentNullException>(() => propertyChangedWeakEventManager.AddEventHandler(null));
-#pragma warning restore CS8625
 		}
 
 		[Fact]
@@ -231,9 +233,7 @@ public void WeakEventManagerDelegate_AddEventHandler_EmptyEventName()
 			// Act
 
 			// Assert
-#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference
 			Assert.Throws<ArgumentNullException>(() => propertyChangedWeakEventManager.AddEventHandler(null, string.Empty));
-#pragma warning restore CS8625
 		}
 
 		[Fact]
@@ -244,9 +244,7 @@ public void WeakEventManagerDelegate_AddEventHandler_WhitespaceEventName()
 			// Act
 
 			// Assert
-#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference
 			Assert.Throws<ArgumentNullException>(() => propertyChangedWeakEventManager.AddEventHandler(null, " "));
-#pragma warning restore CS8625
 		}
 
 		[Fact]
@@ -257,9 +255,7 @@ public void WeakEventManagerDelegate_RemoveEventHandler_NullHandler()
 			// Act
 
 			// Assert
-#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference
 			Assert.Throws<ArgumentNullException>(() => propertyChangedWeakEventManager.RemoveEventHandler(null));
-#pragma warning restore CS8625
 		}
 
 		[Fact]
@@ -283,9 +279,7 @@ public void WeakEventManagerDelegate_RemoveEventHandler_EmptyEventName()
 			// Act
 
 			// Assert
-#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference
 			Assert.Throws<ArgumentNullException>(() => propertyChangedWeakEventManager.RemoveEventHandler(null, string.Empty));
-#pragma warning restore CS8625
 		}
 
 		[Fact]
@@ -296,9 +290,7 @@ public void WeakEventManagerDelegate_RemoveEventHandler_WhiteSpaceEventName()
 			// Act
 
 			// Assert
-#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference
 			Assert.Throws<ArgumentNullException>(() => propertyChangedWeakEventManager.RemoveEventHandler(null, " "));
-#pragma warning restore CS8625
 		}
 	}
 }

src/CommunityToolkit/Xamarin.CommunityToolkit.UnitTests/Helpers/WeakEventManagerTests/DelegateWeakEventManager_EventHandler_Tests.cs

@@ -52,7 +52,9 @@ void HandleTestEvent(object? sender, EventArgs e)
 			}
 
 			// Act
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
 			TestWeakEventManager.RaiseEvent(null, new EventArgs(), nameof(TestEvent));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
 
 			// Assert
 			Assert.True(didEventFire);
@@ -145,7 +147,9 @@ public void WeakEventManager_UnassignedEvent()
 			void HandleTestEvent(object? sender, EventArgs e) => didEventFire = true;
 
 			// Act
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
 			TestWeakEventManager.RaiseEvent(null, null, nameof(TestEvent));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
 
 			// Assert
 			Assert.False(didEventFire);
@@ -162,7 +166,9 @@ public void WeakEventManager_UnassignedEventManager()
 			void HandleTestEvent(object? sender, EventArgs e) => didEventFire = true;
 
 			// Act
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
 			unassignedEventManager.RaiseEvent(null, null, nameof(TestEvent));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
 
 			// Assert
 			Assert.False(didEventFire);

src/CommunityToolkit/Xamarin.CommunityToolkit.UnitTests/Helpers/WeakEventManagerTests/WeakEventManager_ActionT_Tests.cs

@@ -140,7 +140,9 @@ public void WeakEventManagerActionT_AddEventHandler_NullHandler()
 			// Act
 
 			// Assert
+#pragma warning disable CS8604 // Possible null reference argument.
 			Assert.Throws<ArgumentNullException>(() => actionEventManager.AddEventHandler(nullAction, nameof(ActionEvent)));
+#pragma warning restore CS8604 // Possible null reference argument.
 
 		}
 
@@ -152,7 +154,9 @@ public void WeakEventManagerActionT_AddEventHandler_NullEventName()
 			// Act
 
 			// Assert
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
 			Assert.Throws<ArgumentNullException>(() => actionEventManager.AddEventHandler(s => { var temp = s; }, null));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
 		}
 
 		[Fact]
@@ -164,7 +168,9 @@ public void WeakEventManagerActionT_AddEventHandler_EmptyEventName()
 			// Act
 
 			// Assert
+#pragma warning disable CS8604 // Possible null reference argument.
 			Assert.Throws<ArgumentNullException>(() => actionEventManager.AddEventHandler(nullAction, string.Empty));
+#pragma warning restore CS8604 // Possible null reference argument.
 		}
 
 		[Fact]
@@ -187,7 +193,9 @@ public void WeakEventManagerActionT_RemoveEventHandler_NullHandler()
 			// Act
 
 			// Assert
+#pragma warning disable CS8604 // Possible null reference argument.
 			Assert.Throws<ArgumentNullException>(() => actionEventManager.RemoveEventHandler(nullAction));
+#pragma warning restore CS8604 // Possible null reference argument.
 		}
 
 		[Fact]
@@ -198,7 +206,9 @@ public void WeakEventManagerActionT_RemoveEventHandler_NullEventName()
 			// Act
 
 			// Assert
+#pragma warning disable CS8625 // Cannot convert null literal to non-nullable reference type.
 			Assert.Throws<ArgumentNullException>(() => actionEventManager.RemoveEventHandler(s => { var temp = s; }, null));
+#pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
 		}
 
 		[Fact]