Create and run Roslyn analyzers

using System.Collections.Immutable; using System.Linq; using Microsoft.CodeAnalysis; using Microsoft.CodeAnalysis.CSharp; using Microsoft.CodeAnalysis.CSharp.Syntax; using Microsoft.CodeAnalysis.Diagnostics; namespace MyCustomAnalyzer { [DiagnosticAnalyzer(LanguageNames.CSharp)] public sealed class EmptyCatchBlockAnalyzer : DiagnosticAnalyzer { public const string DiagnosticId = "MCA0001"; private static readonly DiagnosticDescriptor Rule = new( id: DiagnosticId, title: "Avoid empty catch blocks", messageFormat: "Empty catch block should be avoided", category: "Reliability", defaultSeverity: DiagnosticSeverity.Warning, isEnabledByDefault: true, description: "Reports catch clauses with an empty block. Empty catches can hide failures and make debugging harder." ); public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule); public override void Initialize(AnalysisContext context) { context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None); context.EnableConcurrentExecution(); context.RegisterSyntaxNodeAction(AnalyzeCatchClause, SyntaxKind.CatchClause); } private static void AnalyzeCatchClause(SyntaxNodeAnalysisContext context) { var catchClause = (CatchClauseSyntax)context.Node; // catch { } or catch (Exception) { } var block = catchClause.Block; if (block is null) return; // Ignore non-empty catches if (block.Statements.Count != 0) return; // Ignore catches that have comments inside (often intentionally empty) if (block.DescendantTrivia().Any(t => t.IsKind(SyntaxKind.SingleLineCommentTrivia) || t.IsKind(SyntaxKind.MultiLineCommentTrivia))) return; context.ReportDiagnostic(Diagnostic.Create(Rule, catchClause.CatchKeyword.GetLocation())); } } }