Extend output language support with C# 13 and 14

Author: Rpinski

backend/ILSpyX.Backend/Application/ILSpyBackendSettings.cs

@@ -2,12 +2,13 @@
 using ICSharpCode.Decompiler.CSharp;
 using ICSharpCode.Decompiler.CSharp.OutputVisitor;
 using ILSpyX.Backend.Model;
+using System.Diagnostics.CodeAnalysis;
 
 namespace ILSpyX.Backend.Application;
 
 public class ILSpyBackendSettings
 {
-    private CSharpFormattingOptions formattingOptions;
+    private readonly CSharpFormattingOptions formattingOptions;
 
     public ILSpyBackendSettings()
     {
@@ -26,6 +27,7 @@ public DecompilerSettings CreateDecompilerSettings(string outputLanguage = Langu
         return decompilerSettings;
     }
 
+    [SuppressMessage("ReSharper", "RedundantSwitchExpressionArms")]
     private LanguageVersion GetCSharpLanguageVersion(string languageName)
     {
         return languageName switch
@@ -45,7 +47,9 @@ private LanguageVersion GetCSharpLanguageVersion(string languageName)
             LanguageName.CSharp_10 => LanguageVersion.CSharp10_0,
             LanguageName.CSharp_11 => LanguageVersion.CSharp11_0,
             LanguageName.CSharp_12 => LanguageVersion.CSharp12_0,
-            _ => LanguageVersion.CSharp12_0,
+            LanguageName.CSharp_13 => LanguageVersion.CSharp13_0,
+            LanguageName.CSharp_14 => LanguageVersion.CSharp14_0,
+            _ => LanguageVersion.CSharp14_0,
         };
     }
 }

backend/ILSpyX.Backend/Model/LanguageNames.cs

@@ -18,5 +18,7 @@ public static class LanguageName
     public const string CSharp_10 = "cs-10";
     public const string CSharp_11 = "cs-11";
     public const string CSharp_12 = "cs-12";
-    public const string CSharpLatest = CSharp_12;
+    public const string CSharp_13 = "cs-13";
+    public const string CSharp_14 = "cs-14";
+    public const string CSharpLatest = CSharp_14;
 }

vscode-extension/package.json

@@ -32,8 +32,10 @@
 					"ilspy.defaultOutputLanguage": {
 						"description": "Defines to which language or language variant ILSpy will decompile assemblies by default. Note that you can choose a different language for a specific view later.",
 						"type": "string",
-						"default": "C# 12.0 / VS 2022.8",
+						"default": "C# 14.0 / VS 2026",
 						"enum": [
+							"C# 14.0 / VS 2026",
+							"C# 13.0 / VS 2022.12",
 							"C# 12.0 / VS 2022.8",
 							"C# 11.0 / VS 2022.4",
 							"C# 10.0 / VS 2022",
@@ -52,6 +54,8 @@
 							"IL"
 						],
 						"enumDescriptions": [
+							"Decompile to C# 14.0 by default",
+							"Decompile to C# 13.0 by default",
 							"Decompile to C# 12.0 by default",
 							"Decompile to C# 11.0 by default",
 							"Decompile to C# 10.0 by default",

vscode-extension/src/decompiler/languageInfos.ts

@@ -83,9 +83,19 @@ export const languageInfos = createLanguageMap([
     displayName: "C# 12.0 / VS 2022.8",
     vsLanguageMode: "csharp",
   },
+  {
+    name: LanguageName.CSharp_13,
+    displayName: "C# 13.0 / VS 2022.12",
+    vsLanguageMode: "csharp",
+  },
+  {
+    name: LanguageName.CSharp_14,
+    displayName: "C# 14.0 / VS 2026",
+    vsLanguageMode: "csharp",
+  },
 ]);
 
-export const LATEST_OUTPUT_LANGUAGE: LanguageName = LanguageName.CSharp_12;
+export const LATEST_OUTPUT_LANGUAGE: LanguageName = LanguageName.CSharp_14;
 
 export const languageFromDisplayName = (name?: string) =>
   Object.entries(languageInfos).find(

vscode-extension/src/protocol/LanguageName.ts

@@ -20,4 +20,6 @@ export enum LanguageName {
   CSharp_10 = "cs-10",
   CSharp_11 = "cs-11",
   CSharp_12 = "cs-12",
+  CSharp_13 = "cs-13",
+  CSharp_14 = "cs-14",
 }