Adds code fixer for: Report error on duplicate [Id(x)] (ORLEANS0012)

src/Orleans.Analyzers/IdClashAttributeAnalyzer.cs

@@ -45,7 +45,7 @@ private void CheckSyntaxNode(SyntaxNodeAnalysisContext context)
             return;
         }
 
-        List<AttributeArgumentBag<int>> bags = new();
+        List<AttributeArgumentBag<int>> bags = [];
         foreach (var memberDeclaration in typeDeclaration.Members.OfType<MemberDeclarationSyntax>())
         {
             var attributes = memberDeclaration.AttributeLists.GetAttributeSyntaxes(Constants.IdAttributeName);
@@ -78,11 +78,16 @@ private void CheckSyntaxNode(SyntaxNodeAnalysisContext context)
             {
                 foreach (var bag in filteredBags)
                 {
+                    var builder = ImmutableDictionary.CreateBuilder<string, string>();
+
+                    builder.Add("IdValue", bag.Value.ToString());
+
                     context.ReportDiagnostic(Diagnostic.Create(
                        descriptor: Rule,
-                       location: bag.Location));
+                       location: bag.Location,
+                       properties: builder.ToImmutable()));
                 }
             }
         }
     }
-}
+}

src/Orleans.Analyzers/IdClashAttributeCodeFix.cs

@@ -0,0 +1,56 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using System.Collections.Immutable;
+using System.Composition;
+using System.Linq;
+using System.Threading.Tasks;
+using static Microsoft.CodeAnalysis.CSharp.SyntaxFactory;
+
+namespace Orleans.Analyzers;
+
+[ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(IdClashAttributeCodeFix)), Shared]
+public class IdClashAttributeCodeFix : CodeFixProvider
+{
+    public override ImmutableArray<string> FixableDiagnosticIds => ImmutableArray.Create(IdClashAttributeAnalyzer.RuleId);
+    public override FixAllProvider GetFixAllProvider() => WellKnownFixAllProviders.BatchFixer;
+
+    public override async Task RegisterCodeFixesAsync(CodeFixContext context)
+    {
+        var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
+        var diagnostic = context.Diagnostics.First();
+        if (root.FindNode(diagnostic.Location.SourceSpan) is not AttributeSyntax attribute)
+        {
+            return;
+        }
+
+        var idValue = diagnostic.Properties["IdValue"];
+
+        context.RegisterCodeFix(
+            CodeAction.Create(
+                Resources.IdClashDetectedTitle,
+                createChangedDocument: _ =>
+                {
+                    var newIdValue = root
+                        .DescendantNodes()
+                        .OfType<AttributeSyntax>()
+                        .Where(a => a.IsAttribute(Constants.IdAttributeName))
+                        .Select(a => int.Parse(a.ArgumentList.Arguments.Single().ToString()))
+                        .ToList()
+                        .Max() + 1;
+
+                    var newAttribute = attribute.ReplaceNode(
+                        attribute.ArgumentList.Arguments[0].Expression,
+                        LiteralExpression(SyntaxKind.StringLiteralExpression, Literal(newIdValue)));
+
+                    var newRoot = root.ReplaceNode(attribute, newAttribute);
+                    var newDocument = context.Document.WithSyntaxRoot(newRoot);
+
+                    return Task.FromResult(newDocument);
+                },
+                equivalenceKey: IdClashAttributeAnalyzer.RuleId),
+            diagnostic);
+    }
+}

src/Orleans.Analyzers/Resources.resx

@@ -169,10 +169,10 @@
     <value>The [Id] attribute must be unique to each members of the declaring type.</value>
   </data>
   <data name="IdClashDetectedMessageFormat" xml:space="preserve">
-    <value>Substitute duplicated [Id] value with the correct unique identity of this member</value>
+    <value>Change duplicated [Id]</value>
   </data>
   <data name="IdClashDetectedTitle" xml:space="preserve">
-    <value>Substitute duplicated [Id] value with the correct unique identity of this member</value>
+    <value>Change duplicated [Id]</value>
   </data>
   <data name="IncorrectAttributeUseMessageFormat" xml:space="preserve">
     <value>Remove attribute [{0}]</value>