WIP

Author: gpanaitescu

src/UiPath.Workflow/XamlIntegration/TextExpressionCompiler.cs

@@ -1525,7 +1525,8 @@ private void GenerateExpressionGetTreeMethod(Activity activity, CompiledExpressi
         }
         else if (IsCs)
         {
-            expressionText = string.Concat(CSharpLambdaString, coreExpressionText);
+            var safeCastText = SafeCastText(coreExpressionText, expressionDescriptor.ResultType);
+            expressionText = string.Concat(CSharpLambdaString, safeCastText);
         }
 
         if (expressionText != null)
@@ -1570,7 +1571,16 @@ private CodeMemberMethod GenerateGetMethod(Activity activity, Type resultType, s
             new CodeAttributeDeclaration(new CodeTypeReference(typeof(DebuggerHiddenAttribute))));
 
         AlignText(activity, ref expressionText, out var pragma);
-        CodeStatement statement = new CodeMethodReturnStatement(new CodeSnippetExpression(expressionText));
+        CodeStatement statement;
+        if (IsCs)
+        {
+            statement = new CodeMethodReturnStatement(SafeCast(expressionText, resultType));
+        }
+        else
+        {
+            statement = new CodeMethodReturnStatement(new CodeSnippetExpression(expressionText));
+        }
+        
         statement.LinePragma = pragma;
         expressionMethod.Statements.Add(statement);
 
@@ -2512,6 +2522,36 @@ private string GetActivityFullName(TextExpressionCompilerSettings settings)
         return activityFullName;
     }
 
+    private string GetFriendlyTypeName(Type type)
+    {
+        using var codeDomProvider = CodeDomProvider.CreateProvider(_settings.Language);
+        return type is null ? null : codeDomProvider.GetTypeOutput(new CodeTypeReference(type));
+    }
+
+    /// <summary>
+    /// Safely formats a string representation of a variable name and its target type.
+    /// </summary>
+    /// <param name="variableName">The name of the variable to be cast. If null or whitespace, "null" is used instead.</param>
+    /// <param name="targetType">The target <see cref="Type"/> to which the variable is being cast.</param>
+    /// <returns>A string in the format "<paramref name="variableName"/> as <paramref name="targetType"/>".</returns>
+    private string SafeCastText(string variableName, Type targetType)
+    {
+        string varName = string.IsNullOrWhiteSpace(variableName) ? "null" : variableName;
+        string typeName = GetFriendlyTypeName(targetType);
+        if (typeName == null)
+        {
+            return varName;
+        }
+        return $"{varName} as {typeName}";
+    }
+
+    /// <summary>
+    /// Creates a CodeSnippetExpression like: "variableName as TargetType".
+    /// If variableName or targetType is null/empty, falls back to "null".
+    /// </summary>
+    private CodeSnippetExpression SafeCast(string variableName, Type targetType)
+        => new CodeSnippetExpression(SafeCastText(variableName, targetType));
+
     private class ExpressionCompilerActivityVisitor : CompiledExpressionActivityVisitor
     {
         private readonly TextExpressionCompiler _compiler;