Enable CA1862 and fix noncompliance

"Use the 'StringComparison' method overloads to perform case-insensitive
string comparisons"

.global.editorconfig.ini

@@ -73,6 +73,8 @@ dotnet_diagnostic.CA1822.severity = silent
 dotnet_code_quality.CA1826.exclude_ordefault_methods = true
 # Avoid StringBuilder parameters for P/Invokes
 dotnet_diagnostic.CA1838.severity = suggestion
+# Use the 'StringComparison' method overloads to perform case-insensitive string comparisons
+dotnet_diagnostic.CA1862.severity = error
 
 ## Usage rules
 

src/BizHawk.Client.Common/RomGame.cs

@@ -63,7 +63,9 @@ namespace BizHawk.Client.Common
 					NotInDatabase = true
 				};
 
+#pragma warning disable CA1862 // testing whether it's all-caps
 				if (!string.IsNullOrWhiteSpace(GameInfo.Name) && GameInfo.Name == GameInfo.Name.ToUpperInvariant())
+#pragma warning restore CA1862
 				{
 					GameInfo.Name = Thread.CurrentThread.CurrentCulture.TextInfo.ToTitleCase(GameInfo.Name.ToLowerInvariant());
 				}

src/BizHawk.Client.Common/RomLoader.cs

@@ -655,7 +655,7 @@ namespace BizHawk.Client.Common
 		private static bool IsDiscForXML(string system, string path)
 		{
 			var ext = Path.GetExtension(path);
-			if (system == VSystemID.Raw.Arcade && ext.ToLowerInvariant() == ".chd")
+			if (system is VSystemID.Raw.Arcade && ".chd".EqualsIgnoreCase(ext))
 			{
 				return false;
 			}

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

@@ -4,6 +4,7 @@ using System.Drawing.Imaging;
 using BizHawk.Bizware.Graphics;
 using BizHawk.Client.Common;
 using BizHawk.Common.PathExtensions;
+using BizHawk.Common.StringExtensions;
 using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.EmuHawk
@@ -49,11 +50,11 @@ namespace BizHawk.Client.EmuHawk
 			var name = Path.Combine(dir!, $"{fileNoExt}_{_frame}{ext}");
 			BitmapBuffer bb = new BitmapBuffer(source.BufferWidth, source.BufferHeight, source.GetVideoBuffer());
 			using var bmp = bb.ToSysdrawingBitmap();
-			if (ext.ToUpperInvariant() == ".PNG")
+			if (".PNG".EqualsIgnoreCase(ext))
 			{
 				bmp.Save(name, ImageFormat.Png);
 			}
-			else if (ext.ToUpperInvariant() == ".JPG")
+			else if (".JPG".EqualsIgnoreCase(ext))
 			{
 				bmp.Save(name, ImageFormat.Jpeg);
 			}

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

@@ -6,7 +6,7 @@ using System.Text;
 using System.Threading;
 
 using BizHawk.Client.Common;
-
+using BizHawk.Common.StringExtensions;
 using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.EmuHawk
@@ -600,7 +600,7 @@ namespace BizHawk.Client.EmuHawk
 		public void OpenFile(string baseName)
 		{
 			string ext = Path.GetExtension(baseName);
-			if (ext == null || ext.ToLowerInvariant() != ".jmd")
+			if (ext?.EqualsIgnoreCase(".jmd") is true or null)
 			{
 				baseName += ".jmd";
 			}

src/BizHawk.Client.EmuHawk/ArchiveChooser.cs

@@ -5,6 +5,7 @@ using System.Text.RegularExpressions;
 using System.Windows.Forms;
 
 using BizHawk.Common;
+using BizHawk.Common.StringExtensions;
 
 namespace BizHawk.Client.EmuHawk
 {
@@ -33,9 +34,7 @@ namespace BizHawk.Client.EmuHawk
 				lvi.SubItems.Add(new ListViewItem.ListViewSubItem());
 				lvi.Text = item.Name;
 				long size = item.Size;
-				var extension = Path.GetExtension(item.Name);
+				if (size % 1024 is 16 && Path.GetExtension(item.Name)?.EqualsIgnoreCase(".NES") is true) size -= 16;
-				if (extension != null && size % 1024 == 16 && extension.ToUpperInvariant() == ".NES")
-					size -= 16;
 				lvi.SubItems[1].Text = Util.FormatFileSize(size);
 				_archiveItems.Add(lvi);
 			}

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -1388,7 +1388,7 @@ namespace BizHawk.Client.EmuHawk
 			using (var bb = Config.ScreenshotCaptureOsd ? CaptureOSD() : MakeScreenshotImage())
 			{
 				using var img = bb.ToSysdrawingBitmap();
-				if (Path.GetExtension(path).ToUpperInvariant() == ".JPG")
+				if (".JPG".EqualsIgnoreCase(Path.GetExtension(path)))
 				{
 					img.Save(fi.FullName, ImageFormat.Jpeg);
 				}
@@ -3724,7 +3724,8 @@ namespace BizHawk.Client.EmuHawk
 					InputManager.SyncControls(Emulator, MovieSession, Config);
 					_multiDiskMode = false;
 
-					if (oaOpenrom != null && Path.GetExtension(oaOpenrom.Path.Replace("|", "")).ToLowerInvariant() == ".xml" && Emulator is not LibsnesCore)
+					if (oaOpenrom is not null && ".xml".EqualsIgnoreCase(Path.GetExtension(oaOpenrom.Path.Replace("|", "")))
+						&& Emulator is not LibsnesCore)
 					{
 						// this is a multi-disk bundler file
 						// determine the xml assets and create RomStatusDetails for all of them

src/BizHawk.Emulation.Common/Database/Database.cs

@@ -487,7 +487,9 @@ namespace BizHawk.Emulation.Common
 			game.Name = Path.GetFileNameWithoutExtension(fileName)?.Replace('_', ' ');
 
 			// If filename is all-caps, then attempt to proper-case the title.
+#pragma warning disable CA1862 // testing whether it's all-caps
 			if (!string.IsNullOrWhiteSpace(game.Name) && game.Name == game.Name.ToUpperInvariant())
+#pragma warning restore CA1862
 			{
 				game.Name = Thread.CurrentThread.CurrentCulture.TextInfo.ToTitleCase(game.Name.ToLowerInvariant());
 			}

src/BizHawk.Emulation.Cores/Arcades/MAME/MAME.cs

@@ -251,7 +251,7 @@ namespace BizHawk.Emulation.Cores.Arcades.MAME
 			foreach (var rom in roms)
 			{
 				// only close non-chd files
-				if (rom.Extension.ToLowerInvariant() != ".chd")
+				if (!".chd".EqualsIgnoreCase(rom.Extension))
 				{
 					_exe.RemoveReadonlyFile(MakeFileName(rom));
 				}

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/CSW/CswConverter.cs

@@ -3,6 +3,8 @@
 using System.Collections.Generic;
 using System.Text;
 
+using BizHawk.Common.StringExtensions;
+
 namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 {
 	/// <summary>
@@ -57,7 +59,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			int majorVer = data[8];
 			int minorVer = data[9];
 
-			if (ident.ToUpperInvariant() != "COMPRESSED SQUARE WAVE")
+			if (!"COMPRESSED SQUARE WAVE".EqualsIgnoreCase(ident))
 			{
 				// this is not a valid CSW format file
 				return false;
@@ -80,7 +82,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			// (first 22 bytes of the file)
 			string ident = Encoding.ASCII.GetString(data, 0, 22);
 
-			if (ident.ToUpperInvariant() != "COMPRESSED SQUARE WAVE")
+			if (!"COMPRESSED SQUARE WAVE".EqualsIgnoreCase(ident))
 			{
 				// this is not a valid CSW format file
 				throw new Exception($"{nameof(CswConverter)}: This is not a valid CSW format file");

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/PZX/PzxConverter.cs

@@ -3,6 +3,8 @@
 using System.Collections.Generic;
 using System.Text;
 
+using BizHawk.Common.StringExtensions;
+
 namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 {
 	/// <summary>
@@ -67,7 +69,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			int majorVer = data[8];
 			int minorVer = data[9];
 
-			if (ident.ToUpperInvariant() != "PZXT")
+			if (!"PZXT".EqualsIgnoreCase(ident))
 			{
 				// this is not a valid PZX format file
 				return false;
@@ -96,7 +98,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			// check whether this is a valid pzx format file by looking at the identifier in the header block
 			string ident = Encoding.ASCII.GetString(data, 0, 4);
 
-			if (ident.ToUpperInvariant() != "PZXT")
+			if (!"PZXT".EqualsIgnoreCase(ident))
 			{
 				// this is not a valid TZX format file
 				throw new Exception($"{nameof(PzxConverter)}: This is not a valid PZX format file");

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/WAV/WavConverter.cs

@@ -2,6 +2,8 @@ using System.Collections.Generic;
 using System.IO;
 using System.Text;
 
+using BizHawk.Common.StringExtensions;
+
 namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 {
 	/// <summary>
@@ -50,7 +52,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			// check whether this is a valid wav format file by looking at the identifier in the header
 			string ident = Encoding.ASCII.GetString(data, 8, 4);
 
-			if (ident.ToUpperInvariant() != "WAVE")
+			if (!"WAVE".EqualsIgnoreCase(ident))
 			{
 				// this is not a valid WAV format file
 				return false;
@@ -72,7 +74,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			// check whether this is a valid pzx format file by looking at the identifier in the header block
 			string ident = Encoding.ASCII.GetString(data, 8, 4);
 
-			if (ident.ToUpperInvariant() != "WAVE")
+			if (!"WAVE".EqualsIgnoreCase(ident))
 			{
 				// this is not a valid TZX format file
 				throw new Exception($"{nameof(WavConverter)}: This is not a valid WAV format file");

src/BizHawk.Emulation.Cores/Consoles/Nintendo/3DS/Encore.cs

@@ -6,6 +6,7 @@ using System.Text;
 
 using BizHawk.BizInvoke;
 using BizHawk.Common;
+using BizHawk.Common.StringExtensions;
 using BizHawk.Emulation.Common;
 
 #pragma warning disable BHI1007 // target-typed Exception TODO don't
@@ -122,7 +123,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.N3DS
 			_serviceProvider.Register<IVideoProvider>(_encoreVideoProvider);
 
 			var romPath = lp.Roms[0].RomPath;
-			if (lp.Roms[0].Extension.ToLowerInvariant() == ".cia")
+			if (".cia".EqualsIgnoreCase(lp.Roms[0].Extension))
 			{
 				var message = new byte[1024];
 				var res = _core.Encore_InstallCIA(_context, romPath, message, message.Length);
@@ -145,7 +146,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.N3DS
 			for (var i = 1; i < lp.Roms.Count; i++)
 			{
 				// doesn't make sense if not a CIA
-				if (lp.Roms[i].Extension.ToLowerInvariant() != ".cia")
+				if (".cia".EqualsIgnoreCase(lp.Roms[i].Extension))
 				{
 					Dispose();
 					throw new("ROMs after the index 0 should be CIAs");

src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.IDebuggable.cs

@@ -35,7 +35,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 
 		public void SetCpuRegister(string register, int value)
 		{
-			if (register.Length == 9 && register.Substring(4, 5).ToUpperInvariant() == " BANK")
+			if (register.Length is 9 && register.EndsWith(" BANK", StringComparison.OrdinalIgnoreCase))
 			{
 				var type = (LibGambatte.BankType)Enum.Parse(typeof(LibGambatte.BankType), register.Substring(0, 4).ToUpperInvariant());
 				LibGambatte.gambatte_setbank(GambatteState, type, value);

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SNES/LibsnesCore.cs

@@ -4,6 +4,7 @@ using System.IO;
 
 using BizHawk.Common;
 using BizHawk.Common.PathExtensions;
+using BizHawk.Common.StringExtensions;
 using BizHawk.Emulation.Common;
 using BizHawk.Emulation.Cores.Components.W65816;
 
@@ -279,7 +280,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 			// every rom requests msu1.rom... why? who knows.
 			// also handle msu-1 pcm files here
 			bool isMsu1Rom = hint == "msu1.rom";
-			bool isMsu1Pcm = Path.GetExtension(hint).ToLowerInvariant() == ".pcm";
+			var isMsu1Pcm = ".pcm".EqualsIgnoreCase(Path.GetExtension(hint));
 			if (isMsu1Rom || isMsu1Pcm)
 			{
 				// well, check if we have an msu-1 xml

src/BizHawk.Emulation.DiscSystem/DiscFormats/CCD_format.cs

@@ -204,7 +204,7 @@ namespace BizHawk.Emulation.DiscSystem
 					var parts = line.Split('=');
 					if (parts.Length != 2)
 						throw new CCDParseException("Malformed or unexpected CCD format: parsing item into two parts");
-					if (parts[0].ToUpperInvariant() == "FLAGS")
+					if ("FLAGS".EqualsIgnoreCase(parts[0]))
 					{
 						// flags are a space-separated collection of symbolic constants:
 						// https://www.gnu.org/software/ccd2cue/manual/html_node/FLAGS-_0028Compact-Disc-fields_0029.html#FLAGS-_0028Compact-Disc-fields_0029

src/BizHawk.Emulation.DiscSystem/DiscIdentifier.cs

@@ -238,7 +238,7 @@ namespace BizHawk.Emulation.DiscSystem
 					return DiscType.Playdia;
 
 				if (sysId is "CDTV" or "AMIGA"
-					|| iso.Root.Children.Keys.Any(k => k.ToLowerInvariant().Contains("cd32")))
+					|| iso.Root.Children.Keys.Any(static k => k.ContainsIgnoreCase("cd32")))
 				{
 					return DiscType.Amiga;
 				}

src/BizHawk.Tests/Emulation.Common/Database/FirmwareDatabaseTests.cs

@@ -22,7 +22,9 @@ namespace BizHawk.Tests.Emulation.Common
 		public void CheckFormatOfHashes()
 		{
 			static void CustomAssert(string hash)
+#pragma warning disable CA1862 // testing whether it's all-caps
 				=> Assert.IsTrue(hash.Length == 40 && hash == hash.ToUpperInvariant() && hash.IsHex(), $"incorrectly formatted: {hash}");
+#pragma warning restore CA1862
 			foreach (var hash in FirmwareDatabase.FirmwareFilesByHash.Keys) CustomAssert(hash);
 			foreach (var fo in FirmwareDatabase.FirmwareOptions) CustomAssert(fo.Hash);
 		}