Enable CA1825 and fix noncompliance (except in Cores)

`new int[0]` and similar

Common.ruleset

@@ -239,7 +239,7 @@
 		<Rule Id="CA1823" Action="Hidden" />
 
 		<!-- Avoid zero-length array allocations. -->
-		<Rule Id="CA1825" Action="Hidden" />
+		<Rule Id="CA1825" Action="Error" />
 
 		<!-- Do not use Count() or LongCount() when Any() can be used -->
 		<Rule Id="CA1827" Action="Error" />

src/BizHawk.BizInvoke/BizInvokeUtilities.cs

@@ -82,7 +82,7 @@ namespace BizHawk.BizInvoke
 			var t = o.GetType();
 			if (t == typeof(OutAttribute) || t == typeof(InAttribute))
 			{
-				return new CustomAttributeBuilder(t.GetConstructor(Type.EmptyTypes)!, new object[0]);
+				return new CustomAttributeBuilder(t.GetConstructor(Type.EmptyTypes)!, Array.Empty<object>());
 			}
 
 			throw new InvalidOperationException($"Unknown parameter attribute {t.Name}");

src/BizHawk.BizInvoke/BizInvokerUtilities.cs

@@ -61,7 +61,7 @@ namespace BizHawk.BizInvoke
 		/// <returns></returns>
 		public static int ComputeStringOffset()
 		{
-			var s = new string(new char[0]);
+			var s = new string(Array.Empty<char>());
 			int ret;
 			fixed(char* fx = s)
 			{

src/BizHawk.Client.Common/DisplayManager/DisplayManagerBase.cs

@@ -535,7 +535,8 @@ namespace BizHawk.Client.Common
 
 		private class FakeVideoProvider : IVideoProvider
 		{
-			public int[] GetVideoBuffer() => new int[] {};
+			public int[] GetVideoBuffer()
+				=> Array.Empty<int>();
 
 			public int VirtualWidth { get; set; }
 			public int VirtualHeight { get; set; }

src/BizHawk.Client.Common/DisplayManager/Filters/Retro.cs

@@ -105,7 +105,7 @@ namespace BizHawk.Client.Common.Filters
 		public readonly string Errors;
 		public readonly IGL Owner;
 		public readonly RetroShaderPreset Preset;
-		public readonly RetroShader[] Shaders = new RetroShader[0];
+		public readonly IReadOnlyList<RetroShader> Shaders = Array.Empty<RetroShader>();
 		public readonly RetroShaderPreset.ShaderPass[] Passes;
 
 		private bool _isDisposed;

src/BizHawk.Client.Common/RomLoader.cs

@@ -817,7 +817,7 @@ namespace BizHawk.Client.Common
 
 			public static readonly IReadOnlyCollection<string> ZXSpectrum = new[] { "tzx", "tap", "dsk", "pzx" };
 
-			public static readonly IReadOnlyCollection<string> AutoloadFromArchive = new string[0]
+			public static readonly IReadOnlyCollection<string> AutoloadFromArchive = Array.Empty<string>()
 				.Concat(A26)
 				.Concat(A78)
 				.Concat(AppleII)
@@ -848,12 +848,12 @@ namespace BizHawk.Client.Common
 
 		/// <remarks>TODO add and handle <see cref="FilesystemFilter.LuaScripts"/> (you can drag-and-drop scripts and there are already non-rom things in this list, so why not?)</remarks>
 		private static readonly FilesystemFilterSet RomFSFilterSet = new FilesystemFilterSet(
-			new FilesystemFilter("Music Files", new string[0], devBuildExtraExts: new[] { "psf", "minipsf", "sid", "nsf" }),
+			new FilesystemFilter("Music Files", Array.Empty<string>(), devBuildExtraExts: new[] { "psf", "minipsf", "sid", "nsf" }),
 			new FilesystemFilter("Disc Images", new[] { "cue", "ccd", "mds", "m3u" }),
 			new FilesystemFilter("NES", RomFileExtensions.NES.Concat(new[] { "nsf" }).ToList(), addArchiveExts: true),
 			new FilesystemFilter("Super NES", RomFileExtensions.SNES, addArchiveExts: true),
 			new FilesystemFilter("PlayStation", new[] { "cue", "ccd", "mds", "m3u" }),
-			new FilesystemFilter("PSX Executables (experimental)", new string[0], devBuildExtraExts: new[] { "exe" }),
+			new FilesystemFilter("PSX Executables (experimental)", Array.Empty<string>(), devBuildExtraExts: new[] { "exe" }),
 			new FilesystemFilter("PSF Playstation Sound File", new[] { "psf", "minipsf" }),
 			new FilesystemFilter("Nintendo 64", RomFileExtensions.N64),
 			new FilesystemFilter("Gameboy", RomFileExtensions.GB, addArchiveExts: true),
@@ -869,13 +869,13 @@ namespace BizHawk.Client.Common
 			new FilesystemFilter("TI-83", RomFileExtensions.TI83, addArchiveExts: true),
 			FilesystemFilter.Archives,
 			new FilesystemFilter("Genesis", RomFileExtensions.GEN.Concat(new[] { "bin", "cue", "ccd" }).ToList(), addArchiveExts: true),
-			new FilesystemFilter("SID Commodore 64 Music File", new string[0], devBuildExtraExts: new[] { "sid" }, devBuildAddArchiveExts: true),
+			new FilesystemFilter("SID Commodore 64 Music File", Array.Empty<string>(), devBuildExtraExts: new[] { "sid" }, devBuildAddArchiveExts: true),
 			new FilesystemFilter("WonderSwan", RomFileExtensions.WSWAN, addArchiveExts: true),
 			new FilesystemFilter("Apple II", RomFileExtensions.AppleII, addArchiveExts: true),
 			new FilesystemFilter("Virtual Boy", RomFileExtensions.VB, addArchiveExts: true),
 			new FilesystemFilter("Neo Geo Pocket", RomFileExtensions.NGP, addArchiveExts: true),
 			new FilesystemFilter("Commodore 64", RomFileExtensions.C64, addArchiveExts: true),
-			new FilesystemFilter("Amstrad CPC", new string[0], devBuildExtraExts: new[] { "cdt", "dsk" }, devBuildAddArchiveExts: true),
+			new FilesystemFilter("Amstrad CPC", Array.Empty<string>(), devBuildExtraExts: new[] { "cdt", "dsk" }, devBuildAddArchiveExts: true),
 			new FilesystemFilter("Sinclair ZX Spectrum", RomFileExtensions.ZXSpectrum.Concat(new[] { "csw", "wav" }).ToList(), addArchiveExts: true),
 			new FilesystemFilter("Odyssey 2", RomFileExtensions.O2),
 			new FilesystemFilter("Uzebox", RomFileExtensions.UZE),

src/BizHawk.Client.Common/Sound/Utilities/SoundOutputProvider.cs

@@ -47,9 +47,9 @@ namespace BizHawk.Client.Common
 		private double _lastAdvertisedSamplesPerFrame;
 		private readonly Queue<int> _baseSamplesPerFrame = new Queue<int>();
 
-		private short[] _outputBuffer = new short[0];
+		private short[] _outputBuffer = Array.Empty<short>();
 
-		private short[] _resampleBuffer = new short[0];
+		private short[] _resampleBuffer = Array.Empty<short>();
 		private double _resampleLengthRoundingError;
 
 		public SoundOutputProvider(Func<double> getCoreVsyncRateCallback, bool standaloneMode = false)
@@ -90,8 +90,8 @@ namespace BizHawk.Client.Common
 			_baseEmptyFrameCorrectionHistory.Clear();
 			_lastAdvertisedSamplesPerFrame = 0.0;
 			_baseSamplesPerFrame.Clear();
-			_outputBuffer = new short[0];
-			_resampleBuffer = new short[0];
+			_outputBuffer = Array.Empty<short>();
+			_resampleBuffer = Array.Empty<short>();
 			_resampleLengthRoundingError = 0.0;
 
 			BaseSoundProvider?.DiscardSamples();

src/BizHawk.Client.Common/movie/import/MovieImport.cs

@@ -47,13 +47,10 @@ namespace BizHawk.Client.Common
 			}
 
 			// Create a new instance of the importer class using the no-argument constructor
-			IMovieImport importer = (IMovieImport)importerType
-				.GetConstructor(new Type[] { })
-				?.Invoke(new object[] { });
 
-			return importer == null
-				? ImportResult.Error($"No importer found for file type {ext}")
-				: importer.Import(dialogParent, session, emulator, path, config);
+			return importerType.GetConstructor(Array.Empty<Type>())?.Invoke(Array.Empty<object>()) is IMovieImport importer
+				? importer.Import(dialogParent, session, emulator, path, config)
+				: ImportResult.Error($"No importer found for file type {ext}");
 		}
 
 		private static Type ImporterForExtension(string ext)

src/BizHawk.Client.Common/movie/tasproj/ZwinderStateManager.cs

@@ -9,7 +9,7 @@ namespace BizHawk.Client.Common
 {
 	public class ZwinderStateManager : IStateManager, IDisposable
 	{
-		private static readonly byte[] NonState = new byte[0];
+		private static readonly byte[] NonState = Array.Empty<byte>();
 
 		private readonly Func<int, bool> _reserveCallback;
 		internal readonly SortedList<int> StateCache = new SortedList<int>();

src/BizHawk.Client.Common/rewind/ZeldaWinder.cs

@@ -17,10 +17,10 @@ namespace BizHawk.Client.Common
 		private readonly ZwinderBuffer _buffer;
 		private readonly IStatable _stateSource;
 
-		private byte[] _master = new byte[0];
+		private byte[] _master = Array.Empty<byte>();
 		private int _masterFrame = -1;
 		private int _masterLength = 0;
-		private byte[] _scratch = new byte[0];
+		private byte[] _scratch = Array.Empty<byte>();
 		private int _count;
 
 		private Task _activeTask = null;

src/BizHawk.Client.EmuHawk/AVOut/AVSync.cs

@@ -51,7 +51,7 @@ namespace BizHawk.Client.EmuHawk
 			W = w;
 		}
 
-		private short[] _samples = new short[0];
+		private short[] _samples = Array.Empty<short>();
 
 		// how many extra audio samples there are (* fpsNum)
 		private long _exAudioNum;

src/BizHawk.Client.EmuHawk/AVOut/AviWriter.cs

@@ -420,8 +420,8 @@ namespace BizHawk.Client.EmuHawk
 			private CodecToken() { }
 			private AVIWriterImports.AVICOMPRESSOPTIONS _comprOptions;
 			public string codec;
-			public byte[] Format = new byte[0];
-			public byte[] Parms = new byte[0];
+			public byte[] Format = Array.Empty<byte>();
+			public byte[] Parms = Array.Empty<byte>();
 
 			private static string Decode_mmioFOURCC(int code)
 			{

src/BizHawk.Client.EmuHawk/AVOut/NutMuxer.cs

@@ -390,7 +390,7 @@ namespace BizHawk.Client.EmuHawk
 			WriteVarU(1, header); // max_pts_distance
 			WriteVarU(0, header); // decode_delay
 			WriteVarU(1, header); // stream_flags = FLAG_FIXED_FPS
-			WriteBytes(new byte[0], header); // codec_specific_data
+			WriteBytes(Array.Empty<byte>(), header); // codec_specific_data
 
 			// stream_class = video
 			WriteVarU(_avParams.Width, header); // width
@@ -414,7 +414,7 @@ namespace BizHawk.Client.EmuHawk
 			WriteVarU(_avParams.Samplerate, header); // max_pts_distance
 			WriteVarU(0, header); // decode_delay
 			WriteVarU(0, header); // stream_flags = none; no FIXED_FPS because we aren't guaranteeing same-size audio chunks
-			WriteBytes(new byte[0], header); // codec_specific_data
+			WriteBytes(Array.Empty<byte>(), header); // codec_specific_data
 
 			// stream_class = audio
 			WriteVarU(_avParams.Samplerate, header); // samplerate_num
@@ -649,12 +649,12 @@ namespace BizHawk.Client.EmuHawk
 		{
 			if (!_videoDone)
 			{
-				WriteVideoFrame(new int[0]);
+				WriteVideoFrame(Array.Empty<int>());
 			}
 
 			if (!_audioDone)
 			{
-				WriteAudioFrame(new short[0]);
+				WriteAudioFrame(Array.Empty<short>());
 			}
 
 			// flush any remaining queued packets

src/BizHawk.Client.EmuHawk/ArchiveChooser.cs

@@ -234,8 +234,7 @@ namespace BizHawk.Client.EmuHawk
 			{
 				return new SimpleMatcher
 				{
-					Keys = searchKey.ToLower().Split(new char[0],
-						StringSplitOptions.RemoveEmptyEntries)
+					Keys = searchKey.ToLower().Split(Array.Empty<char>(), StringSplitOptions.RemoveEmptyEntries) // splits on all whitespace chars
 				};
 			}
 			else

src/BizHawk.Client.EmuHawk/movie/RecordMovie.cs

@@ -134,7 +134,7 @@ namespace BizHawk.Client.EmuHawk
 					}
 
 					// TODO: do we want to support optionally not saving this?
-					movieToRecord.SavestateFramebuffer = new int[0];
+					movieToRecord.SavestateFramebuffer = Array.Empty<int>();
 					if (_emulator.HasVideoProvider())
 					{
 						movieToRecord.SavestateFramebuffer = (int[])_emulator.AsVideoProvider().GetVideoBuffer().Clone();

src/BizHawk.Client.EmuHawk/tools/CDL.cs

@@ -116,7 +116,7 @@ namespace BizHawk.Client.EmuHawk
 			tsbLoggingActive.Checked = value;
 		}
 
-		private string[][] _listContents = new string[0][];
+		private string[][] _listContents = Array.Empty<string[]>();
 
 		private unsafe void UpdateDisplay(bool force)
 		{

src/BizHawk.Client.EmuHawk/tools/HexEditor/HexEditor.cs

@@ -363,9 +363,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private byte[] ConvertHexStringToByteArray(string str)
 		{
-			if (string.IsNullOrWhiteSpace(str)) {
-				return new byte[0];
-			}
+			if (string.IsNullOrWhiteSpace(str)) return Array.Empty<byte>();
 
 			// TODO: Better method of handling this?
 			if (str.Length % 2 == 1)

src/BizHawk.Client.EmuHawk/tools/SNES/SNESGraphicsDebugger.cs

@@ -421,7 +421,7 @@ namespace BizHawk.Client.EmuHawk
 				int bgnum = (int)selection;
 				var bg = si.BG[bgnum];
 
-				map = new SNESGraphicsDecoder.TileEntry[0];
+				map = Array.Empty<SNESGraphicsDecoder.TileEntry>();
 				viewBgMode = bg.BGMode;
 
 				//bool handled = false;

src/BizHawk.Client.EmuHawk/tools/ToolManager.cs

@@ -394,10 +394,8 @@ namespace BizHawk.Client.EmuHawk
 				RefreshSettings(form, dest, settings, idx);
 				form.Size = oldSize;
 
-				form.GetType()
-					.GetMethodsWithAttrib(typeof(RestoreDefaultsAttribute))
-					.FirstOrDefault()
-					?.Invoke(form, new object[0]);
+				form.GetType().GetMethodsWithAttrib(typeof(RestoreDefaultsAttribute))
+					.FirstOrDefault()?.Invoke(form, Array.Empty<object>());
 			};
 		}
 

src/BizHawk.Common/Serializer.cs

@@ -197,7 +197,7 @@ namespace BizHawk.Common
 			}
 			else
 			{
-				var temp = val ?? new byte[0];
+				var temp = val ?? Array.Empty<byte>();
 				_tw.WriteLine("{0} {1}", name, temp.BytesToHexString());
 			}
 		}
@@ -213,7 +213,7 @@ namespace BizHawk.Common
 				val = _br.ReadByteBuffer(false).ToBoolBuffer();
 				if (val == null && !useNull)
 				{
-					val = new bool[0];
+					val = Array.Empty<bool>();
 				}
 			}
 			else
@@ -239,7 +239,7 @@ namespace BizHawk.Common
 			}
 			else
 			{
-				var temp = val ?? new bool[0];
+				var temp = val ?? Array.Empty<bool>();
 				_tw.WriteLine("{0} {1}", name, temp.ToUByteBuffer().BytesToHexString());
 			}
 		}
@@ -254,7 +254,7 @@ namespace BizHawk.Common
 				val = _br.ReadByteBuffer(false).ToShortBuffer();
 				if (val == null && !useNull)
 				{
-					val = new short[0];
+					val = Array.Empty<short>();
 				}
 			}
 			else
@@ -274,7 +274,7 @@ namespace BizHawk.Common
 				val = _br.ReadByteBuffer(false).ToUShortBuffer();
 				if (val == null && !useNull)
 				{
-					val = new ushort[0];
+					val = Array.Empty<ushort>();
 				}
 			}
 			else
@@ -300,7 +300,7 @@ namespace BizHawk.Common
 			}
 			else
 			{
-				var temp = val ?? new short[0];
+				var temp = val ?? Array.Empty<short>();
 				_tw.WriteLine("{0} {1}", name, temp.ToUByteBuffer().BytesToHexString());
 			}
 		}
@@ -322,7 +322,7 @@ namespace BizHawk.Common
 			}
 			else
 			{
-				var temp = val ?? new ushort[0];
+				var temp = val ?? Array.Empty<ushort>();
 				_tw.WriteLine("{0} {1}", name, temp.ToUByteBuffer().BytesToHexString());
 			}
 		}
@@ -338,7 +338,7 @@ namespace BizHawk.Common
 				val = _br.ReadByteBuffer(false).ToIntBuffer();
 				if (val == null && !useNull)
 				{
-					val = new int[0];
+					val = Array.Empty<int>();
 				}
 			}
 			else
@@ -364,7 +364,7 @@ namespace BizHawk.Common
 			}
 			else
 			{
-				var temp = val ?? new int[0];
+				var temp = val ?? Array.Empty<int>();
 				_tw.WriteLine("{0} {1}", name, temp.ToUByteBuffer().BytesToHexString());
 			}
 		}
@@ -380,7 +380,7 @@ namespace BizHawk.Common
 				val = _br.ReadByteBuffer(false).ToUIntBuffer();
 				if (val == null && !useNull)
 				{
-					val = new uint[0];
+					val = Array.Empty<uint>();
 				}
 			}
 			else
@@ -406,7 +406,7 @@ namespace BizHawk.Common
 			}
 			else
 			{
-				var temp = val ?? new uint[0];
+				var temp = val ?? Array.Empty<uint>();
 				_tw.WriteLine("{0} {1}", name, temp.ToUByteBuffer().BytesToHexString());
 			}
 		}
@@ -422,7 +422,7 @@ namespace BizHawk.Common
 				val = _br.ReadByteBuffer(false).ToFloatBuffer();
 				if (val == null && !useNull)
 				{
-					val = new float[0];
+					val = Array.Empty<float>();
 				}
 			}
 			else
@@ -448,7 +448,7 @@ namespace BizHawk.Common
 			}
 			else
 			{
-				var temp = val ?? new float[0];
+				var temp = val ?? Array.Empty<float>();
 				_tw.WriteLine("{0} {1}", name, temp.ToUByteBuffer().BytesToHexString());
 			}
 		}
@@ -464,7 +464,7 @@ namespace BizHawk.Common
 				val = _br.ReadByteBuffer(false).ToDoubleBuffer();
 				if (val == null && !useNull)
 				{
-					val = new double[0];
+					val = Array.Empty<double>();
 				}
 			}
 			else
@@ -490,7 +490,7 @@ namespace BizHawk.Common
 			}
 			else
 			{
-				var temp = val ?? new double[0];
+				var temp = val ?? Array.Empty<double>();
 				_tw.WriteLine("{0} {1}", name, temp.ToUByteBuffer().BytesToHexString());
 			}
 		}

src/BizHawk.Common/SpanStream.cs

@@ -30,7 +30,7 @@ namespace BizHawk.Common
 			{
 				_stream = stream;
 			}
-			private byte[] _buffer = new byte[0];
+			private byte[] _buffer = Array.Empty<byte>();
 			private readonly Stream _stream;
 			public unsafe int Read(Span<byte> buffer)
 			{

src/BizHawk.Emulation.Common/Base Implementations/NullSound.cs

@@ -12,7 +12,7 @@ namespace BizHawk.Emulation.Common
 		private readonly long _spfNumerator;
 		private readonly long _spfDenominator;
 		private long _remainder;
-		private short[] _buff = new short[0];
+		private short[] _buff = Array.Empty<short>();
 
 		private NullSound()
 		{

src/BizHawk.Emulation.Common/Base Implementations/SimpleSyncSoundProvider.cs

@@ -7,7 +7,7 @@ namespace BizHawk.Emulation.Common.Base_Implementations
 	/// </summary>
 	public class SimpleSyncSoundProvider : ISoundProvider
 	{
-		private short[] _buffer = new short[0];
+		private short[] _buffer = Array.Empty<short>();
 		private int _nsamp;
 
 		public bool CanProvideAsync => false;

src/BizHawk.Emulation.Common/DSKIdentifier.cs

@@ -1,5 +1,6 @@
 #nullable disable
 
+using System;
 using System.Linq;
 using System.Text;
 
@@ -238,7 +239,7 @@ namespace BizHawk.Emulation.Common
 			{
 				if (TrackSizes[i] == 0)
 				{
-					Tracks[i] = new Track { Sectors = new Sector[0] };
+					Tracks[i] = new() { Sectors = Array.Empty<Sector>() };
 					continue;
 				}
 				int p = pos;
@@ -313,7 +314,7 @@ namespace BizHawk.Emulation.Common
 			{
 				if (TrackSizes[i] == 0)
 				{
-					Tracks[i] = new Track { Sectors = new Sector[0] };
+					Tracks[i] = new() { Sectors = Array.Empty<Sector>() };
 					continue;
 				}
 				int p = pos;

src/BizHawk.Emulation.Common/Interfaces/Services/ISettable.cs

@@ -110,7 +110,7 @@ namespace BizHawk.Emulation.Common
 		public bool HasSyncSettings { get; }
 
 		private readonly object[] _tempObject = new object[1];
-		private static readonly object[] Empty = new object[0];
+		private static readonly object[] Empty = Array.Empty<object>();
 
 		private readonly MethodInfo _gets;
 		private readonly MethodInfo _puts;

src/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj

@@ -5,7 +5,7 @@
 	<Import Project="../MainSlnCommon.props" />
 	<PropertyGroup>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-		<NoWarn>$(NoWarn);CA1806;CA2214;SA1100;SA1120;SA1137;SA1205;SA1208;SA1400</NoWarn>
+		<NoWarn>$(NoWarn);CA1806;CA1825;CA2214;SA1100;SA1120;SA1137;SA1205;SA1208;SA1400</NoWarn>
 		<Nullable>disable</Nullable>
 	</PropertyGroup>
 	<ItemGroup>

src/BizHawk.Tests/Client.Common/Movie/ZwinderStateManagerTests.cs

@@ -574,7 +574,7 @@ namespace BizHawk.Tests.Client.Common.Movie
 		private class StateSource : IStatable
 		{
 			public int Frame { get; set; }
-			public byte[] PaddingData { get; set; } = new byte[0];
+			public byte[] PaddingData { get; set; } = Array.Empty<byte>();
 			public void LoadStateBinary(BinaryReader reader)
 			{
 				Frame = reader.ReadInt32();