Fix ObjectIsFrozenException when using string.IsNullOrEmpty/IsNullOrWhiteSpace in Where lambda bindings

src/Framework/Framework/Compilation/Javascript/Ast/JsAstHelpers.cs

@@ -73,6 +73,8 @@ public static ParametrizedCode FormatParametrizedScript(this JsNode node, bool n
         {
             if (node is null)
                 throw new ArgumentNullException(nameof(node));
+            // FixParenthesis modifies the tree in-place; if the node is frozen we must clone it first
+            if (node.IsFrozen) node = node.Clone();
             node = node.FixParenthesis();
             var visitor = new JsFormattingVisitor(niceMode, indent);
             node.AcceptVisitor(visitor);

src/Tests/Binding/JavascriptCompilationTests.cs

@@ -1,23 +1,26 @@
-using DotVVM.Framework.Binding;
-using DotVVM.Framework.Controls;
-using DotVVM.Framework.Runtime;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Linq.Expressions;
+using System.Text.Json.Serialization;
 using System.Threading.Tasks;
+using DotVVM.Framework.Binding;
+using DotVVM.Framework.Binding.Expressions;
+using DotVVM.Framework.Binding.Properties;
 using DotVVM.Framework.Compilation;
 using DotVVM.Framework.Compilation.Binding;
 using DotVVM.Framework.Compilation.ControlTree;
 using DotVVM.Framework.Compilation.Javascript;
 using DotVVM.Framework.Compilation.Javascript.Ast;
-using DotVVM.Framework.Testing;
 using DotVVM.Framework.Configuration;
-using System.Linq.Expressions;
-using Microsoft.Extensions.DependencyInjection;
+using DotVVM.Framework.Controls;
+using DotVVM.Framework.Runtime;
+using DotVVM.Framework.Testing;
 using DotVVM.Framework.Utils;
 using DotVVM.Framework.ViewModel;
-using System.Text.Json.Serialization;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using static DotVVM.Framework.Configuration.FreezableUtils;
 
 namespace DotVVM.Framework.Tests.Binding
 {
@@ -1511,6 +1514,19 @@ public void JavascriptCompilation_StringFunctions(string input, string expected)
             Assert.AreEqual(expected, result);
         }
 
+        [TestMethod]
+        [DataRow("VmArray.Where(v => string.IsNullOrEmpty(v.SomeString)).ToList()")]
+        [DataRow("VmArray.Where(v => string.IsNullOrWhiteSpace(v.SomeString)).ToList()")]
+        // Regression test: FormatParametrizedScript was called on a frozen JsBinaryExpression (from string.IsNullOrEmpty/IsNullOrWhiteSpace
+        // translation) causing ObjectIsFrozenException when computing SimplePathExpressionBindingProperty.
+        public void JavascriptCompilation_IsNullOrEmpty_InWhereLambda_DoesNotThrowOnSimplePathExpression(string expression)
+        {
+            var binding = bindingHelper.ValueBinding<IEnumerable<TestViewModel2>>(
+                expression,
+                new[] { typeof(TestViewModel) });
+            var simplePath = binding.GetProperty(typeof(SimplePathExpressionBindingProperty), ErrorHandlingMode.ThrowException);
+        }
+
         [TestMethod]
         public void JavascriptCompilation_CustomPrimitiveToString()
         {