Simplify

src/Analyzers/CSharp/CodeFixes/AddExplicitCast/CSharpAddExplicitCastCodeFixProvider.cs

@@ -13,7 +13,6 @@
 using Microsoft.CodeAnalysis.LanguageService;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.Simplification;
 
 namespace Microsoft.CodeAnalysis.CSharp.CodeFixes.AddExplicitCast;
 
@@ -38,7 +37,7 @@ internal sealed partial class CSharpAddExplicitCastCodeFixProvider()
 
     public override ImmutableArray<string> FixableDiagnosticIds => [CS0266, CS1503];
 
-    protected override void GetPartsOfCastOrConversionExpression(ExpressionSyntax expression, out SyntaxNode type, out SyntaxNode castedExpression)
+    protected override void GetPartsOfCastOrConversionExpression(ExpressionSyntax expression, out SyntaxNode type, out ExpressionSyntax castedExpression)
     {
         var castExpression = (CastExpressionSyntax)expression;
         type = castExpression.Type;
@@ -94,11 +93,9 @@ protected override bool TryGetTargetTypeInfo(
         return !potentialConversionTypes.IsEmpty;
     }
 
-    protected override bool TryLanguageSpecificFix(
-        SemanticModel semanticModel, SyntaxNode currentRoot, ExpressionSyntax targetNode, CancellationToken cancellationToken, [NotNullWhen(true)] out SyntaxNode? replacement)
+    protected override (SyntaxNode finalTarget, SyntaxNode finalReplacement) Cast(
+        SemanticModel semanticModel, ExpressionSyntax targetNode, ITypeSymbol conversionType)
     {
-        replacement = null;
-
         // The compiler is very ambiguous with assignment expressions `(a += b)`.  An error on it may be an error on the
         // entire expression or on the RHS of the assignment. Have to reverse engineer what it is doing here.
         if (targetNode is AssignmentExpressionSyntax assignmentExpression &&
@@ -112,13 +109,11 @@ protected override bool TryLanguageSpecificFix(
                 var conversion = semanticModel.Compilation.ClassifyConversion(rightType, leftType);
                 if (conversion.Exists && conversion.IsExplicit)
                 {
-                    replacement = currentRoot.ReplaceNode(
-                        assignmentExpression.Right,
-                        this.Cast(assignmentExpression.Right, leftType));
+                    return (assignmentExpression.Right, this.Cast(assignmentExpression.Right, leftType));
                 }
             }
         }
 
-        return replacement != null;
+        return base.Cast(semanticModel, targetNode, conversionType);
     }
 }

src/Analyzers/Core/CodeFixes/AddExplicitCast/AbstractAddExplicitCastCodeFixProvider.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.Collections.Immutable;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -15,7 +14,6 @@
 using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.CodeAnalysis.Shared.Collections;
 using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.Simplification;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CodeFixes.AddExplicitCast;
@@ -30,7 +28,7 @@ internal abstract partial class AbstractAddExplicitCastCodeFixProvider<TExpressi
     private const int MaximumConversionOptions = 3;
 
     protected abstract TExpressionSyntax Cast(TExpressionSyntax expression, ITypeSymbol type);
-    protected abstract void GetPartsOfCastOrConversionExpression(TExpressionSyntax expression, out SyntaxNode type, out SyntaxNode castedExpression);
+    protected abstract void GetPartsOfCastOrConversionExpression(TExpressionSyntax expression, out SyntaxNode type, out TExpressionSyntax castedExpression);
 
     /// <summary>
     /// Output the current type information of the target node and the conversion type(s) that the target node is
@@ -91,8 +89,12 @@ public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
 
             actions.Add(CodeAction.Create(
                 title,
-                cancellationToken => Task.FromResult(document.WithSyntaxRoot(
-                    ApplyFix(document, semanticModel, root, targetNode, conversionType, cancellationToken))),
+                cancellationToken =>
+                {
+                    var (finalTarget, replacement) = ApplyFix(document, semanticModel, targetNode, conversionType, cancellationToken);
+
+                    return Task.FromResult(document.WithSyntaxRoot(root.ReplaceNode(finalTarget, replacement)));
+                },
                 title));
         }
 
@@ -101,10 +103,9 @@ public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
             context.Diagnostics);
     }
 
-    private SyntaxNode ApplyFix(
+    private (SyntaxNode finalTarget, SyntaxNode finalReplacement) ApplyFix(
         Document document,
         SemanticModel semanticModel,
-        SyntaxNode currentRoot,
         TExpressionSyntax targetNode,
         ITypeSymbol conversionType,
         CancellationToken cancellationToken)
@@ -126,28 +127,22 @@ private SyntaxNode ApplyFix(
                 if (firstConversion is { IsImplicit: false, IsReference: true } or { IsIdentity: true } &&
                     secondConversion is { IsImplicit: false, IsReference: true })
                 {
-                    return currentRoot.ReplaceNode(
-                        targetNode,
-                        this.Cast((TExpressionSyntax)castedExpression, conversionType)
-                            .WithTriviaFrom(targetNode));
+                    return (targetNode, this.Cast(castedExpression, conversionType).WithTriviaFrom(targetNode));
                 }
             }
         }
-        else if (TryLanguageSpecificFix(semanticModel, currentRoot, targetNode, cancellationToken, out var replacement))
-        {
-            return replacement;
-        }
 
-        return currentRoot.ReplaceNode(
-            targetNode,
-            this.Cast(targetNode, conversionType));
+        return Cast(semanticModel, targetNode, conversionType);
     }
 
+    protected virtual (SyntaxNode finalTarget, SyntaxNode finalReplacement) Cast(SemanticModel semanticModel, TExpressionSyntax targetNode, ITypeSymbol conversionType)
+        => (targetNode, this.Cast(targetNode, conversionType));
+
     protected virtual bool TryLanguageSpecificFix(
         SemanticModel semanticModel, SyntaxNode currentRoot, TExpressionSyntax targetNode, CancellationToken cancellationToken,
-        [NotNullWhen(true)] out SyntaxNode? replacement)
+        out (SyntaxNode finalTarget, SyntaxNode replacement) result)
     {
-        replacement = null;
+        result = default;
         return false;
     }
 
@@ -223,7 +218,7 @@ await editor.ApplyExpressionLevelSemanticEditsAsync(
                 if (TryGetTargetTypeInfo(document, semanticModel, root, diagnostics[0].Id, spanNode, cancellationToken, out var potentialConversionTypes) &&
                     potentialConversionTypes.Length == 1)
                 {
-                    return ApplyFix(document, semanticModel, root, potentialConversionTypes[0].node, potentialConversionTypes[0].type, cancellationToken);
+                    var (newTarget, newReplacement) = ApplyFix(document, semanticModel, root, potentialConversionTypes[0].node, potentialConversionTypes[0].type, cancellationToken);
                 }
 
                 return root;

src/Analyzers/VisualBasic/CodeFixes/AddExplicitCast/VisualBasicAddExplicitCastCodeFixProvider.vb

@@ -14,7 +14,6 @@ Imports Microsoft.CodeAnalysis.PooledObjects
 Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.AddExplicitCast
-
     <ExportCodeFixProvider(LanguageNames.VisualBasic, Name:=PredefinedCodeFixProviderNames.AddExplicitCast), [Shared]>
     Partial Friend NotInheritable Class VisualBasicAddExplicitCastCodeFixProvider
         Inherits AbstractAddExplicitCastCodeFixProvider(Of ExpressionSyntax)
@@ -34,7 +33,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.AddExplicitCast
 
         Public Overrides ReadOnly Property FixableDiagnosticIds As ImmutableArray(Of String) = ImmutableArray.Create(BC30512, BC42016, BC30518, BC30519)
 
-        Protected Overrides Sub GetPartsOfCastOrConversionExpression(expression As ExpressionSyntax, ByRef type As SyntaxNode, ByRef castedExpression As SyntaxNode)
+        Protected Overrides Sub GetPartsOfCastOrConversionExpression(
+                expression As ExpressionSyntax,
+                ByRef type As SyntaxNode,
+                ByRef castedExpression As ExpressionSyntax)
             Dim directCastExpression = TryCast(expression, DirectCastExpressionSyntax)
             If directCastExpression IsNot Nothing Then
                 type = directCastExpression.Type