Find Static Method Code Issue: Listing 1

Full code for custom code issue

Listing 1: Find Static Method Code Issue
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.Linq;
using System.Threading;
using Roslyn.Compilers;
using Roslyn.Compilers.Common;
using Roslyn.Compilers.CSharp;
using Roslyn.Services;
using Roslyn.Services.Editor;

namespace VSMRolynCTP.DemoCodeIssue
{
    [ExportSyntaxNodeCodeIssueProvider("VSMRolynCTP.DemoCodeIssue", LanguageNames.CSharp,
        typeof(MethodDeclarationSyntax))]
    class CodeIssueProvider : ICodeIssueProvider
    {
        private readonly ICodeActionEditFactory editFactory;

        [ImportingConstructor]
        public CodeIssueProvider(ICodeActionEditFactory editFactory)
        {
            this.editFactory = editFactory;
        }

        public IEnumerable GetIssues(IDocument document, CommonSyntaxNode node,
 CancellationToken cancellationToken)
        {
            var methodDeclaration = (MethodDeclarationSyntax)node;
            var semanticModel = document.GetSemanticModel(cancellationToken);

            if (methodDeclaration.DescendentTokens().Any(x => x.Kind == 
SyntaxKind.StaticKeyword))
            {
                yield return null;
            }
            else
            {
                IEnumerable memberIdentifiers = from m in
 methodDeclaration.DescendentNodes()
                                                                where m as IdentifierNameSyntax
 != null
                                                                &&
 IsClassMember(cancellationToken,semanticModel,m as ExpressionSyntax)
                                                                select m as IdentifierNameSyntax;

                if (!memberIdentifiers.Any())
                {
                    yield return new CodeIssue(CodeIssue.Severity.Info, methodDeclaration.Span,
                   String.Format("{0} can be made static.", methodDeclaration));
                }
            }
        }

        private static bool IsClassMember(CancellationToken cancellationToken, ISemanticModel
 semanticModel, ExpressionSyntax syntax)
        {
            bool isMember = false;

            var memberInfo = semanticModel.GetSemanticInfo(syntax, cancellationToken);
            
            if (memberInfo.Symbol != null && !memberInfo.Symbol.IsStatic && 
                memberInfo.Symbol.OriginalDefinition.Kind != CommonSymbolKind.Local)
            { 
                isMember = true;
            }

            return isMember;
        }

        #region Unimplemented ICodeIssueProvider members

        public IEnumerable GetIssues(IDocument document, CommonSyntaxToken token,
 CancellationToken cancellationToken)
        {
            throw new NotImplementedException();
        }

        public IEnumerable GetIssues(IDocument document, CommonSyntaxTrivia trivia,
 CancellationToken cancellationToken)
        {
            throw new NotImplementedException();
        }

        #endregion
    }
}

About the Author

Eric Vogel is a Senior Software Developer for Red Cedar Solutions Group in Okemos, Michigan. He is the president of the Greater Lansing User Group for .NET. Eric enjoys learning about software architecture and craftsmanship, and is always looking for ways to create more robust and testable applications. Contact him at vogelvision@gmail.com.