Merge pull request #22 from delegateas/copilot/add-helper-methods-rule

Add CT0011: prevent suppressing MA0051 (method too long)

Author: magesoe

src/DataverseAnalyzer/PragmaWarningDisableMA0051Analyzer.cs

@@ -0,0 +1,53 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+namespace DataverseAnalyzer;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class PragmaWarningDisableMA0051Analyzer : DiagnosticAnalyzer
+{
+    private static readonly Lazy<DiagnosticDescriptor> LazyRule = new(() => new DiagnosticDescriptor(
+        "CT0011",
+        Resources.CT0011_Title,
+        Resources.CT0011_MessageFormat,
+        "Usage",
+        DiagnosticSeverity.Warning,
+        isEnabledByDefault: true,
+        description: Resources.CT0011_Description));
+
+    public static DiagnosticDescriptor Rule => LazyRule.Value;
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
+
+    public override void Initialize(AnalysisContext context)
+    {
+        if (context is null)
+            throw new ArgumentNullException(nameof(context));
+
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+        context.EnableConcurrentExecution();
+
+        context.RegisterSyntaxNodeAction(AnalyzePragmaWarning, SyntaxKind.PragmaWarningDirectiveTrivia);
+    }
+
+    private static void AnalyzePragmaWarning(SyntaxNodeAnalysisContext context)
+    {
+        var pragma = (PragmaWarningDirectiveTriviaSyntax)context.Node;
+
+        if (!pragma.DisableOrRestoreKeyword.IsKind(SyntaxKind.DisableKeyword))
+            return;
+
+        foreach (var errorCode in pragma.ErrorCodes)
+        {
+            if (errorCode is IdentifierNameSyntax identifier &&
+                identifier.Identifier.ValueText == "MA0051")
+            {
+                context.ReportDiagnostic(Diagnostic.Create(Rule, pragma.GetLocation()));
+                return;
+            }
+        }
+    }
+}

src/DataverseAnalyzer/Resources.Designer.cs

@@ -154,4 +154,13 @@
   <data name="CT0010_Description" xml:space="preserve">
     <value>Delete operations cannot have post-images because the record no longer exists after the delete operation. ImageType.Both is also invalid as it includes PostImage.</value>
   </data>
+  <data name="CT0011_Title" xml:space="preserve">
+    <value>Do not suppress MA0051 (method too long)</value>
+  </data>
+  <data name="CT0011_MessageFormat" xml:space="preserve">
+    <value>Do not suppress MA0051. Split the method into smaller helper methods instead.</value>
+  </data>
+  <data name="CT0011_Description" xml:space="preserve">
+    <value>Suppressing MA0051 hides methods that are too long. Instead, split the method into smaller, focused helper methods to improve readability and maintainability.</value>
+  </data>
 </root>

src/DataverseAnalyzer/Resources.resx

@@ -0,0 +1,115 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+namespace DataverseAnalyzer.Tests;
+
+public sealed class PragmaWarningDisableMA0051AnalyzerTests
+{
+    [Fact]
+    public async Task PragmaDisableMA0051ShouldTrigger()
+    {
+        var source = """
+            class TestClass
+            {
+            #pragma warning disable MA0051
+                public void TestMethod() { }
+            #pragma warning restore MA0051
+            }
+            """;
+
+        var diagnostics = await GetDiagnosticsAsync(source);
+        Assert.Single(diagnostics);
+        Assert.Equal("CT0011", diagnostics[0].Id);
+    }
+
+    [Fact]
+    public async Task PragmaDisableMA0051WithOtherWarningsShouldTrigger()
+    {
+        var source = """
+            class TestClass
+            {
+            #pragma warning disable MA0051, CS0168
+                public void TestMethod() { }
+            #pragma warning restore MA0051, CS0168
+            }
+            """;
+
+        var diagnostics = await GetDiagnosticsAsync(source);
+        Assert.Single(diagnostics);
+        Assert.Equal("CT0011", diagnostics[0].Id);
+    }
+
+    [Fact]
+    public async Task PragmaRestoreMA0051ShouldNotTrigger()
+    {
+        var source = """
+            class TestClass
+            {
+            #pragma warning restore MA0051
+                public void TestMethod() { }
+            }
+            """;
+
+        var diagnostics = await GetDiagnosticsAsync(source);
+        Assert.Empty(diagnostics);
+    }
+
+    [Fact]
+    public async Task PragmaDisableOtherWarningShouldNotTrigger()
+    {
+        var source = """
+            class TestClass
+            {
+            #pragma warning disable CS0168
+                public void TestMethod() { }
+            #pragma warning restore CS0168
+            }
+            """;
+
+        var diagnostics = await GetDiagnosticsAsync(source);
+        Assert.Empty(diagnostics);
+    }
+
+    [Fact]
+    public async Task MultiplePragmaDisableMA0051ShouldTriggerMultipleTimes()
+    {
+        var source = """
+            class TestClass
+            {
+            #pragma warning disable MA0051
+                public void TestMethodA() { }
+            #pragma warning restore MA0051
+            #pragma warning disable MA0051
+                public void TestMethodB() { }
+            #pragma warning restore MA0051
+            }
+            """;
+
+        var diagnostics = await GetDiagnosticsAsync(source);
+        Assert.Equal(2, diagnostics.Length);
+        Assert.All(diagnostics, d => Assert.Equal("CT0011", d.Id));
+    }
+
+    private static async Task<Diagnostic[]> GetDiagnosticsAsync(string source)
+    {
+        var syntaxTree = CSharpSyntaxTree.ParseText(source, new CSharpParseOptions(LanguageVersion.Latest));
+        var references = new List<MetadataReference>
+        {
+            MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
+        };
+
+        var compilation = CSharpCompilation.Create(
+            "TestAssembly",
+            new[] { syntaxTree },
+            references,
+            new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));
+
+        var analyzer = new PragmaWarningDisableMA0051Analyzer();
+        var compilationWithAnalyzers = compilation.WithAnalyzers(ImmutableArray.Create<DiagnosticAnalyzer>(analyzer));
+
+        var diagnostics = await compilationWithAnalyzers.GetAnalyzerDiagnosticsAsync();
+        return diagnostics.Where(d => d.Id == "CT0011").ToArray();
+    }
+}