[Foundation] Improve nullability in NSArray.ToArray.

src/CoreVideo/CVPixelBufferAttributes.cs

@@ -88,7 +88,7 @@ public CVPixelFormatType []? PixelFormatTypes {
 				} else if (obj is NSNumber number) {
 					return new CVPixelFormatType [] { (CVPixelFormatType) number.UInt32Value };
 				} else if (obj is NSArray array) {
-					return Array.ConvertAll (array.ToArray (), (v) => (CVPixelFormatType) ((NSNumber) v).UInt32Value);
+					return Array.ConvertAll<NSObject?, CVPixelFormatType> (array.ToArray (), (v) => (CVPixelFormatType) (((NSNumber?) v)?.UInt32Value ?? default));
 				} else {
 					throw new InvalidOperationException ($"Unable to convert object of type {obj.GetType ()} into an array of CVPixelFormatType.");
 				}

src/Foundation/NSArray.cs

@@ -29,8 +29,7 @@
 
 using CoreFoundation;
 
-// Disable until we get around to enable + fix any issues.
-#nullable disable
+#nullable enable
 
 namespace Foundation {
 
@@ -39,8 +38,6 @@ namespace Foundation {
 #endif
 
 	public partial class NSArray : IEnumerable<NSObject> {
-
-#nullable enable
 		/// <summary>Creates an NSArray from a C# array of NSObjects.</summary>
 		/// <param name="items">Strongly typed array of NSObjects. Null elements are stored as <see cref="NSNull.Null"/>. If the array itself is null, an empty <see cref="NSArray"/> is returned.</param>
 		/// <returns>A new <see cref="NSArray"/> containing the specified objects.</returns>
@@ -1008,17 +1005,42 @@ internal static T [] NonNullDictionaryArrayFromHandleDropNullElements<T> (Native
 			GC.KeepAlive (this);
 			return rv;
 		}
-#nullable disable
 
-		public TKey [] ToArray<TKey> () where TKey : class, INativeObject
+		/// <summary>Converts this <see cref="NSArray" /> to a strongly-typed C# array, dropping null and incompatible elements.</summary>
+		/// <typeparam name="T">The element type for the returned array. Must be a class that implements <see cref="INativeObject" />.</typeparam>
+		/// <returns>A C# array of <typeparamref name="T" /> elements, excluding any null or incompatible elements.</returns>
+		internal T [] NonNullToArrayDropNullElements<T> () where T : class, INativeObject
+		{
+			var rv = NonNullArrayFromHandleDropNullElements<T> (Handle);
+			GC.KeepAlive (this);
+			return rv;
+		}
+
+		/// <summary>Converts this <see cref="NSArray" /> to a C# array by first resolving each element to <typeparamref name="V" />, then converting to <typeparamref name="T" />, dropping null elements.</summary>
+		/// <typeparam name="T">The target element type for the returned array.</typeparam>
+		/// <typeparam name="V">The intermediate native object type used to convert each element. Must be a class that implements <see cref="INativeObject" />.</typeparam>
+		/// <param name="createObject">A delegate to convert an instance of <typeparamref name="V" /> to <typeparamref name="T" />.</param>
+		/// <returns>A C# array of <typeparamref name="T" /> elements, excluding any null elements.</returns>
+		internal T []? NonNullToArrayDropNullElements<T, V> (Converter<V, T> createObject) where V : class, INativeObject
 		{
-			var rv = new TKey [GetCount (Handle)];
-			for (var i = 0; i < rv.Length; i++)
-				rv [i] = GetItem<TKey> ((nuint) i);
+			var rv = NonNullArrayFromHandleDropNullElements<T> (Handle, (handle) => createObject (Runtime.GetINativeObject<V> (handle, false)!));
+			GC.KeepAlive (this);
+			return rv;
+		}
+
+		/// <summary>Converts this <see cref="NSArray" /> to a strongly-typed C# array, where <see cref="NSNull" /> elements are converted to <see langword="null" />.</summary>
+		/// <typeparam name="TKey">The element type for the returned array. Must be a class that implements <see cref="INativeObject" />.</typeparam>
+		/// <returns>A C# array of <typeparamref name="TKey" /> elements. Elements that are <see cref="NSNull" /> in the source array are represented as <see langword="null" />.</returns>
+		public TKey? [] ToArray<TKey> () where TKey : class, INativeObject
+		{
+			var rv = NonNullArrayFromHandle<TKey> (Handle, NSNullBehavior.ConvertToNull);
+			GC.KeepAlive (this);
 			return rv;
 		}
 
-		public NSObject [] ToArray ()
+		/// <summary>Converts this <see cref="NSArray" /> to a C# array of <see cref="NSObject" />, where <see cref="NSNull" /> elements are converted to <see langword="null" />.</summary>
+		/// <returns>A C# array of <see cref="NSObject" /> elements. Elements that are <see cref="NSNull" /> in the source array are represented as <see langword="null" />.</returns>
+		public NSObject? [] ToArray ()
 		{
 			return ToArray<NSObject> ();
 		}

src/Foundation/NSArray_1.cs

@@ -118,7 +118,9 @@ public TKey? this [nint idx] {
 			}
 		}
 
-		public new TKey [] ToArray ()
+		/// <summary>Converts this <see cref="NSArray{TKey}" /> to a strongly-typed C# array, where <see cref="NSNull" /> elements are converted to <see langword="null" />.</summary>
+		/// <returns>A C# array of <typeparamref name="TKey" /> elements. Elements that are <see cref="NSNull" /> in the source array are represented as <see langword="null" />.</returns>
+		public new TKey? [] ToArray ()
 		{
 			return base.ToArray<TKey> ();
 		}

src/appkit.cs

@@ -13711,7 +13711,7 @@ partial interface NSPasteboard // NSPasteboard does _not_ implement NSPasteboard
 		void DetectValues (HashSet<NSPasteboardDetectionPattern> patterns, NSPasteboardDetectValuesHandler completionHandler);
 
 		[Mac (15, 4)]
-		[Wrap ("DetectValues (NSSet<NSString>.Create (patterns, (v) => NSPasteboardDetectionPatternExtensions.GetConstant (v)!), new NSPasteboardDetectValuesHandler ((detectedValues, error) => completionHandler (detectedValues?.ToDictionary<NSPasteboardDetectionPattern, DataDetection.DDMatch[]> ((k, v) => (NSPasteboardDetectionPatternExtensions.GetValue (k), ((NSArray) v).ToArray<DataDetection.DDMatch> ())), error)))")]
+		[Wrap ("DetectValues (NSSet<NSString>.Create (patterns, (v) => NSPasteboardDetectionPatternExtensions.GetConstant (v)!), new NSPasteboardDetectValuesHandler ((detectedValues, error) => completionHandler (detectedValues?.ToDictionary<NSPasteboardDetectionPattern, DataDetection.DDMatch[]> ((k, v) => (NSPasteboardDetectionPatternExtensions.GetValue (k), ((NSArray) v).NonNullToArrayDropNullElements<DataDetection.DDMatch> ())), error)))")]
 		void DetectValues (HashSet<NSPasteboardDetectionPattern> patterns, NSPasteboardDetectValuesCompletionHandler completionHandler);
 
 		[Mac (15, 4)]
@@ -13943,7 +13943,7 @@ interface NSPasteboardItem : NSPasteboardWriting, NSPasteboardReading {
 		void DetectValues (HashSet<NSPasteboardDetectionPattern> patterns, NSPasteboardDetectValuesHandler completionHandler);
 
 		[Mac (15, 4)]
-		[Wrap ("DetectValues (NSSet<NSString>.Create (patterns, (v) => NSPasteboardDetectionPatternExtensions.GetConstant (v)!), new NSPasteboardDetectValuesHandler ((detectedValues, error) => completionHandler (detectedValues?.ToDictionary<NSPasteboardDetectionPattern, DataDetection.DDMatch[]> ((k, v) => (NSPasteboardDetectionPatternExtensions.GetValue (k), ((NSArray) v).ToArray<DataDetection.DDMatch> ())), error)))")]
+		[Wrap ("DetectValues (NSSet<NSString>.Create (patterns, (v) => NSPasteboardDetectionPatternExtensions.GetConstant (v)!), new NSPasteboardDetectValuesHandler ((detectedValues, error) => completionHandler (detectedValues?.ToDictionary<NSPasteboardDetectionPattern, DataDetection.DDMatch[]> ((k, v) => (NSPasteboardDetectionPatternExtensions.GetValue (k), ((NSArray) v).NonNullToArrayDropNullElements<DataDetection.DDMatch> ())), error)))")]
 		void DetectValues (HashSet<NSPasteboardDetectionPattern> patterns, NSPasteboardDetectValuesCompletionHandler completionHandler);
 
 		[Mac (15, 4)]

tests/cecil-tests/Documentation.KnownFailures.txt

@@ -11800,9 +11800,6 @@ M:Foundation.INSUrlSessionTaskDelegate.NeedNewBodyStream(Foundation.NSUrlSession
 M:Foundation.INSUrlSessionWebSocketDelegate.DidClose(Foundation.NSUrlSession,Foundation.NSUrlSessionWebSocketTask,Foundation.NSUrlSessionWebSocketCloseCode,Foundation.NSData)
 M:Foundation.INSUrlSessionWebSocketDelegate.DidOpen(Foundation.NSUrlSession,Foundation.NSUrlSessionWebSocketTask,System.String)
 M:Foundation.INSXpcListenerDelegate.ShouldAcceptConnection(Foundation.NSXpcListener,Foundation.NSXpcConnection)
-M:Foundation.NSArray.ToArray
-M:Foundation.NSArray.ToArray``1
-M:Foundation.NSArray`1.ToArray
 M:Foundation.NSAttributedString.#ctor(System.String,AppKit.NSFont,AppKit.NSColor,AppKit.NSColor,AppKit.NSColor,AppKit.NSColor,AppKit.NSColor,Foundation.NSUnderlineStyle,Foundation.NSUnderlineStyle,AppKit.NSParagraphStyle,System.Single,AppKit.NSShadow,Foundation.NSUrl,System.Boolean,AppKit.NSTextAttachment,Foundation.NSLigatureType,System.Single,System.Single,System.Single,System.Single,AppKit.NSCursor,System.String,System.Int32,AppKit.NSGlyphInfo,Foundation.NSArray,System.Boolean,AppKit.NSTextLayoutOrientation,AppKit.NSTextAlternatives,AppKit.NSSpellingState)
 M:Foundation.NSAttributedString.LoadDataAsync(System.String,Foundation.NSProgress@)
 M:Foundation.NSAttributedString.LoadFromHtml(Foundation.NSData,Foundation.NSAttributedStringDocumentAttributes,Foundation.NSAttributedStringCompletionHandler)