AK1003 - Add ReceiveAsync with sync lambda analyzer and code fix (#61)

* Add ReceiveAsync with sync lambda analyzer and code fix

* Fix typos

* Make analyzer ignore lambda expression without async keyword

src/Akka.Analyzers.Fixes/AK1000/ShouldNotUseReceiveAsyncWithoutAsyncLambdaFixer.cs

@@ -0,0 +1,113 @@
+// -----------------------------------------------------------------------
+//  <copyright file="ShouldNotUseReceiveAsyncWithoutAsyncLambdaFixer.cs" company="Akka.NET Project">
+//      Copyright (C) 2013-2024 .NET Foundation <https://github.com/akkadotnet/akka.net>
+//  </copyright>
+// -----------------------------------------------------------------------
+
+using System.Composition;
+using System.Runtime.CompilerServices;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Editing;
+
+namespace Akka.Analyzers.Fixes;
+
+[ExportCodeFixProvider(LanguageNames.CSharp)]
+[Shared]
+public class ShouldNotUseReceiveAsyncWithoutAsyncLambdaFixer()
+    : BatchedCodeFixProvider(RuleDescriptors.Ak1003ShouldNotUseReceiveAsyncSynchronously.Id)
+{
+    public const string Key_FixReceiveAsyncWithoutAsync = "AK1003_FixReceiveAsyncWithoutAsync";
+
+    public override async Task RegisterCodeFixesAsync(CodeFixContext context)
+    {
+        var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
+        if (root is null)
+            return;
+
+        var diagnostic = context.Diagnostics.FirstOrDefault();
+        if (diagnostic is null)
+            return;
+        var diagnosticSpan = diagnostic.Location.SourceSpan;
+
+        // Find the ReceiveAsync<T>() invocation identified by the diagnostic
+        var invocationExpr = root.FindToken(diagnosticSpan.Start).Parent?.AncestorsAndSelf().OfType<InvocationExpressionSyntax>().First();
+        if (invocationExpr is null)
+            return;
+
+        context.RegisterCodeFix(
+            CodeAction.Create(
+                title: "Replace ReceiveAsync or ReceiveAnyAsync with Receive or ReceiveAny",
+                createChangedDocument: c => ReplaceReceiveAsyncWithReceiveAsync(context.Document, invocationExpr, c),
+                equivalenceKey: Key_FixReceiveAsyncWithoutAsync),
+            diagnostic);
+    }
+
+    private static async Task<Document> ReplaceReceiveAsyncWithReceiveAsync(Document document,
+        InvocationExpressionSyntax invocationExpr, CancellationToken cancellationToken)
+    {
+        var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
+        if (semanticModel is null)
+            return document;
+
+        // Get the method argument that matches a lambda expression of Func<T, Task>
+        var lambdaArg = invocationExpr.ArgumentList.Arguments
+            .FirstOrDefault(arg => 
+                arg.Expression is LambdaExpressionSyntax expr 
+                && IsFuncOfTTask(semanticModel.GetTypeInfo(expr).ConvertedType));
+        if(lambdaArg is null)
+            return document;
+
+        var editor = await DocumentEditor.CreateAsync(document, cancellationToken).ConfigureAwait(false);
+
+        // Remove "Async" from the method name
+        var newMethodName = invocationExpr.Expression.ToString().Replace("Async", "");
+        var newInvocationExpr = invocationExpr
+            .WithExpression(SyntaxFactory.ParseExpression(newMethodName))
+            .WithTriviaFrom(invocationExpr);
+
+        var lambdaExpr = (LambdaExpressionSyntax)lambdaArg.Expression;
+
+        // Remove 'async' keyword
+        var newLambdaExpr = lambdaExpr.WithAsyncKeyword(default);
+
+        // Remove 'return Task.CompletedTask;'
+        if (lambdaExpr.Body is BlockSyntax blockSyntax)
+        {
+            var newBlockStatements = blockSyntax.Statements
+                .Where(stmt => 
+                    stmt is not ReturnStatementSyntax returnStmt 
+                    || returnStmt.Expression?.ToString() is not "Task.CompletedTask");
+            var newBlock = SyntaxFactory.Block(newBlockStatements).WithTriviaFrom(blockSyntax);
+            newLambdaExpr = newLambdaExpr.WithBlock(newBlock);
+        }
+
+        // replace old lambda argument expression content with the new one
+        var newLambdaArg = lambdaArg.WithExpression(newLambdaExpr);
+        var newArgumentList = SyntaxFactory.ArgumentList(invocationExpr.ArgumentList.Arguments.Replace(lambdaArg, newLambdaArg));
+
+        // replace original method invocation lambda argument with the modified one 
+        newInvocationExpr = newInvocationExpr.WithArgumentList(newArgumentList);
+
+        // replace original method invocation with the modified one
+        editor.ReplaceNode(invocationExpr, newInvocationExpr);
+
+        return editor.GetChangedDocument();
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static bool IsFuncOfTTask(ITypeSymbol? typeSymbol)
+    {
+        if (typeSymbol is not INamedTypeSymbol { DelegateInvokeMethod: not null } namedTypeSymbol) 
+            return false;
+
+        var delegateReturnType = namedTypeSymbol.DelegateInvokeMethod.ReturnType;
+        var delegateParameters = namedTypeSymbol.DelegateInvokeMethod.Parameters;
+
+        return delegateReturnType is INamedTypeSymbol { Name: nameof(Task) }
+               && delegateParameters.Length == 1;
+    }    
+}