AK2001: detect when automatically handled messages are being handled …

…inside MessageExtractor / IMessageExtractor (#43)

src/Akka.Analyzers.Fixes/AK2000/MustNotUseAutomaticallyHandledMessagesInsideMessageExtractorFixer.cs

@@ -0,0 +1,80 @@
+// -----------------------------------------------------------------------
+//  <copyright file="MustNotUseAutomaticallyHandledMessagesInsideMessageExtractorFixer.cs" company="Akka.NET Project">
+//      Copyright (C) 2013-2024 .NET Foundation <https://github.com/akkadotnet/akka.net>
+// </copyright>
+// -----------------------------------------------------------------------
+
+using System.Composition;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.VisualBasic.Syntax;
+using IfStatementSyntax = Microsoft.CodeAnalysis.CSharp.Syntax.IfStatementSyntax;
+
+namespace Akka.Analyzers.Fixes;
+
+[ExportCodeFixProvider(LanguageNames.CSharp)]
+[Shared]
+public class MustNotUseAutomaticallyHandledMessagesInsideMessageExtractorFixer() 
+    : BatchedCodeFixProvider(RuleDescriptors.Ak2001DoNotUseAutomaticallyHandledMessagesInShardMessageExtractor.Id)
+{
+    public const string Key_FixAutomaticallyHandledShardedMessage = "AK2001_FixAutoShardMessage";
+
+    public override async Task RegisterCodeFixesAsync(CodeFixContext context)
+    {
+        var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
+        if (root is null)
+            return;
+
+        var reportedNodes = new HashSet<SyntaxNode>();
+
+        foreach (var diagnostic in context.Diagnostics)
+        {
+            var diagnosticSpan = diagnostic.Location.SourceSpan;
+
+            // Find the token at the location of the diagnostic.
+            var token = root.FindToken(diagnosticSpan.Start);
+
+            // Find the correct parent node to remove.
+            var nodeToRemove = FindParentNodeToRemove(token.Parent);
+
+            // Check if the node has already been processed to avoid duplicates
+            if (nodeToRemove != null && reportedNodes.Add(nodeToRemove))
+            {
+                context.RegisterCodeFix(
+                    CodeAction.Create(
+                        title: "Remove unnecessary message handling",
+                        createChangedDocument: c => RemoveOffendingNode(context.Document, nodeToRemove, c),
+                        equivalenceKey: Key_FixAutomaticallyHandledShardedMessage),
+                    diagnostic);
+            }
+        }
+    }
+
+    private static SyntaxNode? FindParentNodeToRemove(SyntaxNode? node)
+    {
+        while (node != null)
+        {
+            if (node is IfStatementSyntax || node is SwitchSectionSyntax || node is SwitchExpressionArmSyntax)
+            {
+                // special case - have to check for else if here
+                if(node.Parent is ElseClauseSyntax)
+                    return node.Parent;
+                return node;
+            }
+            node = node.Parent;
+        }
+        return null;
+    }
+
+    private static async Task<Document> RemoveOffendingNode(Document document, SyntaxNode nodeToRemove, CancellationToken cancellationToken)
+    {
+        var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+        if(root == null)
+            return document;
+
+        var newRoot = root.RemoveNode(nodeToRemove, SyntaxRemoveOptions.KeepNoTrivia);
+        return newRoot == null ? document : document.WithSyntaxRoot(newRoot);
+    }
+}

src/Akka.Analyzers.Fixes/Akka.Analyzers.Fixes.csproj.DotSettings

@@ -1,2 +1,4 @@
 <wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=ak1000/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=ak2000/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=utility/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>

src/Akka.Analyzers.Tests/Akka.Analyzers.Tests.csproj

@@ -10,7 +10,10 @@
 
     <ItemGroup>
         <!-- Download packages referenced by ReferenceAssembliesHelper -->
+        <!-- TODO: are transitive references downloaded? If so we could trim this list to just Akka.Cluster.Sharding -->
         <PackageDownload Include="Akka" Version="[1.5.14]"/>
+        <PackageDownload Include="Akka.Cluster.Sharding" Version="[1.5.14]"/>
+        <PackageDownload Include="Akka.Cluster" Version="[1.5.14]"/>
     </ItemGroup>
 
     <ItemGroup>