Add dotnet 6 check

Ensure that dotnet 6 is installed when compiling for MacOS ARM.

Author: bman46

ElectronNET.CLI/Commands/Actions/GetTargetPlatformInformation.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.Runtime.InteropServices;
 
 namespace ElectronNET.CLI.Commands.Actions
@@ -30,6 +31,15 @@ public static GetTargetPlatformInformationResult Do(string desiredPlatform, stri
                 case "osx-arm64":
                     netCorePublishRid = "osx-arm64";
                     electronPackerPlatform = "mac";
+
+                    //Check to see if .net 6 is installed:
+                    if (!Dotnet6Installed())
+                    {
+                        throw new ArgumentException("You are using a dotnet version older than dotnet 6. Compiling for osx-arm64 requires that dotnet 6 or greater is installed and targeted by your project.", "osx-arm64");
+                    }
+
+                    //Warn for .net 6 targeting:
+                    Console.WriteLine("Please ensure that your project targets .net 6 or greater. Otherwise you may experience an error compiling for osx-arm64.");
                     break;
                 case "linux":
                     netCorePublishRid = "linux-x64";
@@ -52,8 +62,11 @@ public static GetTargetPlatformInformationResult Do(string desiredPlatform, stri
                     }
                     if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
                     {
-                        if (RuntimeInformation.OSArchitecture.Equals(Architecture.Arm64))
+                        if (RuntimeInformation.OSArchitecture.Equals(Architecture.Arm64) && Dotnet6Installed())
                         {
+                            //Warn for .net 6 targeting:
+                            Console.WriteLine("Please ensure that your project targets .net 6. Otherwise you may experience an error.");
+
                             //Apple Silicon Mac:
                             netCorePublishRid = "osx-arm64";
                             electronPackerPlatform = "mac";
@@ -79,5 +92,37 @@ public static GetTargetPlatformInformationResult Do(string desiredPlatform, stri
                 NetCorePublishRid = netCorePublishRid
             };
         }
+        /// <summary>
+        /// Checks to see if dotnet 6 or greater is installed.
+        /// Required for MacOS arm targeting.
+        /// Note that an error may still occur if the project being compiled does not target dotnet 6 or greater. 
+        /// </summary>
+        /// <returns>
+        /// Returns true if dotnet 6 or greater is installed.
+        /// </returns>
+        private static bool Dotnet6Installed()
+        {
+            //check for .net 6:
+            Process process = new Process();
+            process.StartInfo.FileName = "dotnet";
+            process.StartInfo.Arguments = "--list-sdks";
+            process.StartInfo.UseShellExecute = false;
+            process.StartInfo.RedirectStandardOutput = true;
+            process.StartInfo.RedirectStandardError = true;
+            process.Start();
+
+            string standard_output;
+            bool dotnet6Exists = false;
+            while ((standard_output = process.StandardOutput.ReadLine()) != null)
+            {
+                if (standard_output.StartsWith("6."))
+                {
+                    dotnet6Exists = true;
+                    break;
+                }
+            }
+            process.WaitForExit();
+            return dotnet6Exists;
+        }
     }
-}
+}