Update analyzers for C# 14.0 language version checks

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/UseObservablePropertyOnPartialPropertyAnalyzer.cs

@@ -8,6 +8,9 @@
 using System.Linq;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using Microsoft.CodeAnalysis;
+#if ROSLYN_5_0_0_OR_GREATER
+using Microsoft.CodeAnalysis.CSharp;
+#endif
 using Microsoft.CodeAnalysis.Diagnostics;
 using static CommunityToolkit.Mvvm.SourceGenerators.Diagnostics.DiagnosticDescriptors;
 
@@ -30,9 +33,13 @@ public override void Initialize(AnalysisContext context)
 
         context.RegisterCompilationStartAction(static context =>
         {
-            // Using [ObservableProperty] on partial properties is only supported when using C# preview.
+            // Using [ObservableProperty] on partial properties is only supported without C# 14.0 or above.
             // As such, if that is not the case, return immediately, as no diagnostic should be produced.
+#if ROSLYN_5_0_0_OR_GREATER
+            if (!context.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp14))
+#else
             if (!context.Compilation.IsLanguageVersionPreview())
+#endif
             {
                 return;
             }

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/UseObservablePropertyOnSemiAutoPropertyAnalyzer.cs

@@ -55,7 +55,11 @@ public override void Initialize(AnalysisContext context)
         {
             // Using [ObservableProperty] on partial properties is only supported when using C# preview.
             // As such, if that is not the case, return immediately, as no diagnostic should be produced.
+#if ROSLYN_5_0_0_OR_GREATER
+            if (!context.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp14))
+#else
             if (!context.Compilation.IsLanguageVersionPreview())
+#endif
             {
                 return;
             }

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/WinRTObservablePropertyOnFieldsIsNotAotCompatibleAnalyzer.cs

@@ -11,6 +11,9 @@
 using System.Threading;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
 using Microsoft.CodeAnalysis;
+#if ROSLYN_5_0_0_OR_GREATER
+using Microsoft.CodeAnalysis.CSharp;
+#endif
 using Microsoft.CodeAnalysis.Diagnostics;
 using static CommunityToolkit.Mvvm.SourceGenerators.Diagnostics.DiagnosticDescriptors;
 
@@ -78,9 +81,13 @@ public override void Initialize(AnalysisContext context)
                 }
             }, SymbolKind.Field);
 
-            // If C# preview is already in use, we can stop here. The last diagnostic is only needed when partial properties
+            // If C# is version 14.0 or above, we can stop here. The last diagnostic is only needed when partial properties
             // cannot be used, to inform developers that they'll need to bump the language version to enable the code fixer.
+#if ROSLYN_5_0_0_OR_GREATER
+            if (context.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp14))
+#else
             if (context.Compilation.IsLanguageVersionPreview())
+#endif
             {
                 return;
             }

tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn4120.UnitTests/Test_SourceGeneratorsDiagnostics.cs

@@ -188,6 +188,27 @@ public partial class SampleViewModel : ObservableObject
         await VerifyAnalyzerDiagnosticsAndSuccessfulGeneration<UseObservablePropertyOnPartialPropertyAnalyzer>(source, LanguageVersion.Preview);
     }
 
+#if ROSLYN_5_0_0_OR_GREATER
+    [TestMethod]
+    public async Task UseObservablePropertyOnPartialPropertyAnalyzer_LanguageVersionIsCSharp14_Warns()
+    {
+        const string source = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp
+            {
+                public partial class SampleViewModel : ObservableObject
+                {            
+                    [ObservableProperty]
+                    private string {|MVVMTK0042:name|};
+                }
+            }
+            """;
+
+        await VerifyAnalyzerDiagnosticsAndSuccessfulGeneration<UseObservablePropertyOnPartialPropertyAnalyzer>(source, LanguageVersion.CSharp14);
+    }
+#endif
+
     [TestMethod]
     public async Task UseObservablePropertyOnPartialPropertyAnalyzer_LanguageVersionIsPreview_OnPartialProperty_DoesNotWarn()
     {
@@ -503,6 +524,30 @@ await CSharpAnalyzerWithLanguageVersionTest<WinRTObservablePropertyOnFieldsIsNot
             editorconfig: [("_MvvmToolkitIsUsingWindowsRuntimePack", true), ("CsWinRTAotOptimizerEnabled", "auto")]);
     }
 
+#if ROSLYN_5_0_0_OR_GREATER
+    [TestMethod]
+    public async Task WinRTObservablePropertyOnFieldsIsNotAotCompatibleAnalyzer_TargetingWindows_CsWinRTAotOptimizerEnabled_Auto_LanguageVersionIsCSharp14_Warns()
+    {
+        const string source = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp
+            {
+                public partial class SampleViewModel : ObservableObject
+                {            
+                    [ObservableProperty]
+                    private string {|MVVMTK0045:name|};
+                }
+            }
+            """;
+
+        await CSharpAnalyzerWithLanguageVersionTest<WinRTObservablePropertyOnFieldsIsNotAotCompatibleAnalyzer>.VerifyAnalyzerAsync(
+            source,
+            LanguageVersion.CSharp14,
+            editorconfig: [("_MvvmToolkitIsUsingWindowsRuntimePack", true), ("CsWinRTAotOptimizerEnabled", "auto")]);
+    }
+#endif
+
     [TestMethod]
     public async Task WinRTObservablePropertyOnFieldsIsNotAotCompatibleAnalyzer_TargetingWindows_CsWinRTAotOptimizerEnabled_Auto_NotCSharpPreview_Warns_WithCompilationWarning()
     {
@@ -1471,6 +1516,29 @@ public partial class SampleViewModel : ObservableObject
         await CSharpAnalyzerWithLanguageVersionTest<UseObservablePropertyOnSemiAutoPropertyAnalyzer>.VerifyAnalyzerAsync(source, LanguageVersion.Preview);
     }
 
+#if ROSLYN_5_0_0_OR_GREATER
+    [TestMethod]
+    public async Task UseObservablePropertyOnSemiAutoPropertyAnalyzer_ValidProperty_LanguageVersionIsCSharp14_Warns()
+    {
+        const string source = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp;
+
+            public partial class SampleViewModel : ObservableObject
+            {
+                public string {|MVVMTK0056:Name|}
+                {
+                    get => field;
+                    set => SetProperty(ref field, value);
+                }
+            }
+            """;
+
+        await CSharpAnalyzerWithLanguageVersionTest<UseObservablePropertyOnSemiAutoPropertyAnalyzer>.VerifyAnalyzerAsync(source, LanguageVersion.CSharp14);
+    }
+#endif
+
     [TestMethod]
     public async Task UseObservablePropertyOnSemiAutoPropertyAnalyzer_ValidProperty_WithModifiers_Warns()
     {