Modified forwared constant fields

Author: marcarro

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/CodeActions/Razor/ExtractToComponentCodeActionResolver.cs

@@ -38,6 +38,7 @@
 using Microsoft.VisualStudio.Text;
 using ICSharpCode.Decompiler.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Razor.DocumentMapping;
+using System.Reflection.Metadata.Ecma335;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer.CodeActions;
 
@@ -323,13 +324,14 @@ private static bool TryProcessSelection(MarkupSyntaxNode startElementNode, Marku
         // This conditional handles cases where the user's selection spans across different levels of the DOM.
         // For example:
         //   <div>
-        //     <span>
-        //      Selected text starts here<p>Some text</p>
+        //     {|result:<span>
+        //      {|selection:<p>Some text</p>
         //     </span>
         //     <span>
         //       <p>More text</p>
         //     </span>
-        //     Selected text ends here <span></span>
+        //     <span>|}|}
+        //     </span>
         //   </div>
         // In this case, we need to find the smallest set of complete elements that covers the entire selection.
         if (startElementNode != endElementNode)
@@ -551,7 +553,6 @@ metadata.Value is not null &&
         }
 
         var sourceMappings = razorCodeDocument.GetCSharpDocument().SourceMappings;
-        
         var sourceMappingRanges = sourceMappings.Select(m =>
         (
             new Range
@@ -564,20 +565,17 @@ metadata.Value is not null &&
 
         var relevantTextSpan = relevantRange.ToTextSpan(razorCodeDocument.Source.Text);
         var intersectingGeneratedSpans = sourceMappingRanges.Where(m => relevantRange.IntersectsOrTouches(m.Item1)).Select(m => m.GeneratedSpan).ToArray();
+
+        // I'm not sure why, but for some reason the endCharacterIndex is lower than the CharacterIndex so they must be swapped.
         var intersectingGeneratedRanges = intersectingGeneratedSpans.Select(m =>
         (
             new Range
             {
-                Start = new Position(m.LineIndex, m.CharacterIndex),
+                Start = new Position(m.LineIndex, m.EndCharacterIndex),
                 End = new Position(m.LineIndex, m.CharacterIndex)
             }
         )).ToArray();
 
-        if (!TryMapToClosestGeneratedDocumentRange(razorCodeDocument.GetCSharpDocument(), selectionAnalysis.ExtractStart, selectionAnalysis.ExtractEnd, out var selectionMappedRange))
-        {
-            return result;
-        }
-
         var parameters = new GetSymbolicInfoParams()
         {
             Project = new TextDocumentIdentifier
@@ -594,8 +592,7 @@ metadata.Value is not null &&
             },
             NewContents = newFileContent,
             HostDocumentVersion = version.Value,
-            MappedRange = selectionMappedRange,
-            IntersectingSpansInGeneratedMappings = intersectingGeneratedRanges
+            IntersectingRangesInGeneratedMappings = intersectingGeneratedRanges
         };
 
         SymbolicInfo? componentInfo;
@@ -611,7 +608,6 @@ metadata.Value is not null &&
             throw new InvalidOperationException("Failed to send request to RazorComponentInfoEndpoint", ex);
         }
 
-        // Check if client connection call was successful
         if (componentInfo is null)
         {
             return result;
@@ -624,7 +620,6 @@ metadata.Value is not null &&
         }
 
         var identifiersInCodeBlock = GetIdentifiersInContext(codeBlockAtEnd, cSharpCodeBlocks);
-
         if (componentInfo.Methods is null)
         {
             return result;
@@ -635,8 +630,9 @@ metadata.Value is not null &&
         var methodsInContext = GetMethodsInContext(componentInfo, methodStringsInContext);
         var promotedMethods = GeneratePromotedMethods(methodsInContext);
 
-        var fieldsInContext = GetFieldsInContext(componentInfo, identifiersInCodeBlock);
-        var forwardedFields = GenerateForwardedConstantFields(codeBlockAtEnd, fieldsInContext);
+        var fieldsInContext = GetFieldsInContext(componentInfo.Fields, identifiersInCodeBlock);
+        var forwardedFields = GenerateForwardedConstantFields(fieldsInContext, Path.GetFileName(razorCodeDocument.Source.FilePath));
+
         var newFileCodeBlock = GenerateNewFileCodeBlock(promotedMethods, forwardedFields);
 
         newFileContent = ReplaceMethodInvocations(newFileContent, methodsInContext);
@@ -669,44 +665,6 @@ private static List<CSharpCodeBlockSyntax> GetCSharpCodeBlocks(RazorSyntaxTree s
         return cSharpCodeBlocks;
     }
 
-    private static bool TryMapToClosestGeneratedDocumentRange(RazorCSharpDocument generatedDocument, int start, int end, out Range mappedRange)
-    {
-        var sourceMappings = generatedDocument.SourceMappings;
-
-        var closestStartSourceMap = sourceMappings.OrderBy(m => Math.Abs(m.OriginalSpan.AbsoluteIndex - start)).First();
-        var closestEndSourceMap = sourceMappings.OrderBy(m => Math.Abs(m.OriginalSpan.AbsoluteIndex - end)).First();
-
-        var generatedStart = closestStartSourceMap.GeneratedSpan;
-        var generatedEnd = closestEndSourceMap.GeneratedSpan;
-
-        var generatedStartLinePosition = GetGeneratedPosition(generatedDocument, generatedStart.AbsoluteIndex);
-        var generatedEndLinePosition = GetGeneratedPosition(generatedDocument, generatedEnd.AbsoluteIndex);
-
-        mappedRange = new Range
-        {
-            Start = new Position(generatedStartLinePosition.Line, generatedStartLinePosition.Character),
-            End = new Position(generatedEndLinePosition.Line, generatedEndLinePosition.Character)
-        };
-
-        LinePosition GetGeneratedPosition(IRazorGeneratedDocument generatedDocument, int generatedIndex)
-        {
-            var generatedSource = GetGeneratedSourceText(generatedDocument);
-            return generatedSource.Lines.GetLinePosition(generatedIndex);
-        }
-
-        SourceText GetGeneratedSourceText(IRazorGeneratedDocument generatedDocument)
-        {
-            if (generatedDocument.CodeDocument is not { } codeDocument)
-            {
-                throw new InvalidOperationException("Cannot use document mapping service on a generated document that has a null CodeDocument.");
-            }
-
-            return codeDocument.GetGeneratedSourceText(generatedDocument);
-        }
-
-        return true;
-    }
-
     // Get identifiers in code block to union with the identifiers in the extracted code
     private static HashSet<string> GetIdentifiersInContext(SyntaxNode codeBlockAtEnd, List<CSharpCodeBlockSyntax> previousCodeBlocks)
     {
@@ -745,9 +703,9 @@ private static HashSet<string> GetIdentifiersInContext(SyntaxNode codeBlockAtEnd
         return identifiersInLastCodeBlock;
     }
 
-    private static HashSet<MethodInRazorInfo> GetMethodsInContext(SymbolicInfo componentInfo, IEnumerable<string> methodStringsInContext)
+    private static HashSet<MethodSymbolicInfo> GetMethodsInContext(SymbolicInfo componentInfo, IEnumerable<string> methodStringsInContext)
     {
-        var methodsInContext = new HashSet<MethodInRazorInfo>();
+        var methodsInContext = new HashSet<MethodSymbolicInfo>();
         if (componentInfo.Methods is null)
         {
             return methodsInContext;
@@ -782,7 +740,7 @@ private static HashSet<MethodInRazorInfo> GetMethodsInContext(SymbolicInfo compo
     // Create a series of [Parameter] attributes for extracted methods.
     // Void return functions are promoted to Action<T> delegates.
     // All other functions should be Func<T... TResult> delegates.
-    private static string GeneratePromotedMethods(HashSet<MethodInRazorInfo> methods)
+    private static string GeneratePromotedMethods(HashSet<MethodSymbolicInfo> methods)
     {
         var builder = new StringBuilder();
         var parameterCount = 0;
@@ -838,34 +796,48 @@ private static string GeneratePromotedMethods(HashSet<MethodInRazorInfo> methods
         return builder.ToString();
     }
 
-    private static string GenerateForwardedConstantFields(SyntaxNode codeBlockAtEnd, HashSet<string> relevantFields)
+    private static HashSet<FieldSymbolicInfo> GetFieldsInContext(FieldSymbolicInfo[] fields, HashSet<string> identifiersInCodeBlock)
     {
-        var builder = new StringBuilder();
+        if (fields is null)
+        {
+            return [];
+        }
 
-        var codeBlockString = codeBlockAtEnd.ToFullString();
+        var fieldsInContext = new HashSet<FieldSymbolicInfo>();
 
-        var lines = codeBlockString.Split('\n');
-        foreach (var line in lines)
+        foreach (var fieldInfo in fields)
         {
-            if (relevantFields.Any(field => line.Contains(field)))
+            if (identifiersInCodeBlock.Contains(fieldInfo.Name))
             {
-                builder.AppendLine(line.Trim());
+                fieldsInContext.Add(fieldInfo);
             }
         }
 
-        return builder.ToString();
+        return fieldsInContext;
     }
 
-    // GetFieldsInContext(componentInfo, identifiersInCodeBlock)
-    private static HashSet<string> GetFieldsInContext(SymbolicInfo componentInfo, HashSet<string> identifiersInCodeBlock)
+    private static string GenerateForwardedConstantFields(HashSet<FieldSymbolicInfo> relevantFields, string? sourceDocumentFileName)
     {
-        if (componentInfo.Fields is null)
+        var builder = new StringBuilder();
+        var fieldCount = 0;
+        var totalFields = relevantFields.Count;
+
+        foreach (var field in relevantFields)
         {
-            return [];
+            if (field.IsValueType || field.Type == "string")
+            {
+                builder.AppendLine($"// Warning: Field '{field.Name}' was passed by value and may not be referenced correctly. Please check its usage in the original document: '{sourceDocumentFileName}'.");
+            }
+
+            builder.AppendLine($"public {field.Type} {field.Name}");
+
+            if (fieldCount < totalFields - 1)
+            {
+                builder.AppendLine();
+            }
         }
 
-        var identifiersInFile = componentInfo.Fields.Select(field => field.Name).ToHashSet();
-        return identifiersInFile.Intersect(identifiersInCodeBlock).ToHashSet();
+        return builder.ToString();
     }
 
     private static string GenerateNewFileCodeBlock(string promotedMethods, string carryoverFields)
@@ -881,7 +853,7 @@ private static string GenerateNewFileCodeBlock(string promotedMethods, string ca
     }
 
     // Method invocations in the new file must be replaced with their respective parameter name. This is simply a case of replacing each string.
-    private static string ReplaceMethodInvocations(string newFileContent, HashSet<MethodInRazorInfo> methods)
+    private static string ReplaceMethodInvocations(string newFileContent, HashSet<MethodSymbolicInfo> methods)
     {
         var parameterCount = 0;
         foreach (var method in methods)
@@ -893,7 +865,7 @@ private static string ReplaceMethodInvocations(string newFileContent, HashSet<Me
         return newFileContent;
     }
 
-    private static string GenerateComponentNameAndParameters(HashSet<MethodInRazorInfo>? methods, string componentName)
+    private static string GenerateComponentNameAndParameters(HashSet<MethodSymbolicInfo>? methods, string componentName)
     {
         var builder = new StringBuilder();
         builder.Append(componentName + " ");
@@ -918,6 +890,6 @@ private static string GenerateComponentNameAndParameters(HashSet<MethodInRazorIn
     internal sealed record NewRazorComponentInfo
     {
         public required string NewContents { get; set; }
-        public required HashSet<MethodInRazorInfo>? Methods { get; set; }
+        public required HashSet<MethodSymbolicInfo>? Methods { get; set; }
     }
 }

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Protocol/CodeActions/GetSymbolicInfoParams.cs

@@ -31,23 +31,19 @@ internal record GetSymbolicInfoParams
     [JsonPropertyName("newContents")]
     public required string NewContents { get; set; }
 
-    [DataMember(Name = "mappedRange")]
-    [JsonPropertyName("mappedRange")]
-    public required Range MappedRange { get; set; }
+    [DataMember(Name = "intersectingRangesInGeneratedMappings")]
+    [JsonPropertyName("intersectingRangesInGeneratedMappings")]
 
-    [DataMember(Name = "intersectingSpansInGeneratedRange")]
-    [JsonPropertyName("intersectingSpansInGeneratedRange")]
-
-    public required Range[] IntersectingSpansInGeneratedMappings { get; set; }
+    public required Range[] IntersectingRangesInGeneratedMappings { get; set; }
 }
 
 internal sealed record SymbolicInfo
 {
-    public required MethodInRazorInfo[] Methods { get; set; }
-    public required SymbolInRazorInfo[] Fields { get; set; }
+    public required MethodSymbolicInfo[] Methods { get; set; }
+    public required FieldSymbolicInfo[] Fields { get; set; }
 }
 
-internal sealed record MethodInRazorInfo
+internal sealed record MethodSymbolicInfo
 {
     public required string Name { get; set; }
 
@@ -56,8 +52,10 @@ internal sealed record MethodInRazorInfo
     public required string[] ParameterTypes { get; set; }
 }
 
-internal sealed record SymbolInRazorInfo
+internal sealed record FieldSymbolicInfo
 {
     public required string Name { get; set; }
     public required string Type { get; set; }
+    public required bool IsValueType { get; set; }
+    public required bool IsWrittenTo { get; set; }
 }