refactor: Update code to support .NET 8.0 and newer only (#876)

Co-authored-by: openhands <[email protected]>

Author: buehler

README.md

@@ -12,10 +12,10 @@ detailed documentation, head to the [GitHub Pages](https://buehler.github.io/dot
 
 ## Packages
 
-All packages support .NET6.0 and higher. The reason is that modern C# features are
-used and client libraries are still possible for .NET 6.0 and up.
+All packages support .NET8.0 and higher. The reason is that modern C# features are
+used and client libraries are optimized for .NET 8.0 and up.
 Also, the KubernetesClient package follows the same strategy regarding the
-older framework versions.
+framework versions.
 The following packages exist:
 
 | Package                                                              | Description                                            | Latest Version                                                                                                                                                          |

src/KubeOps.Cli/Transpilation/AssemblyLoader.cs

@@ -183,10 +183,6 @@ private static IEnumerable<TypeInfo> GetTypesToInspect(this MetadataLoadContext
         .SelectMany(a => a.DefinedTypes)
         .Where(t => !t.IsInterface && !t.IsAbstract && !t.IsGenericType);
 
-#if NET7_0_OR_GREATER
     [GeneratedRegex(".*")]
     private static partial Regex DefaultRegex();
-#else
-    private static Regex DefaultRegex() => new(".*");
-#endif
 }

src/KubeOps.Cli/Transpilation/TfmComparer.cs

@@ -1,4 +1,4 @@
-using System.Text.RegularExpressions;
+using System.Text.RegularExpressions;
 
 namespace KubeOps.Cli.Transpilation;
 
@@ -7,17 +7,10 @@ namespace KubeOps.Cli.Transpilation;
 /// </summary>
 internal sealed partial class TfmComparer : IComparer<string>
 {
-#if NET7_0_OR_GREATER
     [GeneratedRegex(
-        "[(]?(?<tfm>(?<name>(netcoreapp|net|netstandard){1})(?<major>[0-9]+)[.](?<minor>[0-9]+))[)]?",
+        "[(]?(?<tfm>(?<n>(netcoreapp|net|netstandard){1})(?<major>[0-9]+)[.](?<minor>[0-9]+))[)]?",
         RegexOptions.Compiled)]
     public static partial Regex TfmRegex();
-#else
-    public static Regex TfmRegex() =>
-        new(
-            "[(]?(?<tfm>(?<name>(netcoreapp|net|netstandard){1})(?<major>[0-9]+)[.](?<minor>[0-9]+))[)]?",
-            RegexOptions.Compiled);
-#endif
 
     public int Compare(string? x, string? y)
     {

src/KubeOps.Operator/LeaderElection/LeaderElectionBackgroundService.cs

@@ -48,11 +48,7 @@ public async Task StopAsync(CancellationToken cancellationToken)
             return;
         }
 
-#if NET8_0_OR_GREATER
         await _cts.CancelAsync();
-#else
-        _cts.Cancel();
-#endif
 
         if (_leadershipTask is not null)
         {

src/KubeOps.Operator/Queue/EntityRequeueBackgroundService.cs

@@ -44,12 +44,7 @@ public Task StopAsync(CancellationToken cancellationToken)
             return Task.CompletedTask;
         }
 
-#if NET8_0_OR_GREATER
         return _cts.CancelAsync();
-#else
-        _cts.Cancel();
-        return Task.CompletedTask;
-#endif
     }
 
     public void Dispose()

src/KubeOps.Operator/Watcher/ResourceWatcher{TEntity}.cs

@@ -62,11 +62,7 @@ public virtual async Task StopAsync(CancellationToken cancellationToken)
             return;
         }
 
-#if NET8_0_OR_GREATER
         await _cancellationTokenSource.CancelAsync();
-#else
-        _cancellationTokenSource.Cancel();
-#endif
         if (_eventWatcher is not null)
         {
             await _eventWatcher.WaitAsync(cancellationToken);

src/KubeOps.Transpiler/Kubernetes/KubernetesVersionComparer.cs

@@ -1,4 +1,4 @@
-using System.Text.RegularExpressions;
+using System.Text.RegularExpressions;
 
 namespace KubeOps.Transpiler.Kubernetes;
 
@@ -10,11 +10,6 @@ namespace KubeOps.Transpiler.Kubernetes;
 /// </summary>
 public sealed partial class KubernetesVersionComparer : IComparer<string>
 {
-#if !NET7_0_OR_GREATER
-    private static readonly Regex KubernetesVersionRegex =
-        new("^v(?<major>[0-9]+)((?<stream>alpha|beta)(?<minor>[0-9]+))?$", RegexOptions.Compiled);
-#endif
-
     private enum Stream
     {
         Alpha = 1,
@@ -29,21 +24,13 @@ public int Compare(string? x, string? y)
             return StringComparer.CurrentCulture.Compare(x, y);
         }
 
-#if NET7_0_OR_GREATER
         var matchX = KubernetesVersionRegex().Match(x);
-#else
-        var matchX = KubernetesVersionRegex.Match(x);
-#endif
         if (!matchX.Success)
         {
             return StringComparer.CurrentCulture.Compare(x, y);
         }
 
-#if NET7_0_OR_GREATER
         var matchY = KubernetesVersionRegex().Match(y);
-#else
-        var matchY = KubernetesVersionRegex.Match(y);
-#endif
         if (!matchY.Success)
         {
             return StringComparer.CurrentCulture.Compare(x, y);
@@ -54,10 +41,8 @@ public int Compare(string? x, string? y)
         return versionX.CompareTo(versionY);
     }
 
-#if NET7_0_OR_GREATER
     [GeneratedRegex("^v(?<major>[0-9]+)((?<stream>alpha|beta)(?<minor>[0-9]+))?$", RegexOptions.Compiled)]
     private static partial Regex KubernetesVersionRegex();
-#endif
 
     private static Version ExtractVersion(Match match)
     {