Fix: Add Fallback in ExpressionPromoter to Handle Cache Cleanup in ConstantExpressionHelper

src/System.Linq.Dynamic.Core/Parser/ExpressionPromoter.cs

@@ -50,7 +50,12 @@ public ExpressionPromoter(ParsingConfig config)
             }
             else
             {
-                if (_constantExpressionHelper.TryGetText(ce, out var text))
+                if (!_constantExpressionHelper.TryGetText(ce, out var text))
+                {
+                    text = ce.Value?.ToString();
+                }
+
+                if (text != null)
                 {
                     Type target = TypeHelper.GetNonNullableType(type);
                     object? value = null;
@@ -67,7 +72,7 @@ public ExpressionPromoter(ParsingConfig config)
                             // Make sure an enum value stays an enum value
                             if (target.IsEnum)
                             {
-                                value = Enum.ToObject(target, value!);
+                                TypeHelper.TryParseEnum(text, target, out value);
                             }
                             break;
 

test/System.Linq.Dynamic.Core.Tests/Parser/ExpressionPromoterTests.cs

@@ -1,56 +1,132 @@
-using Moq;
+using FluentAssertions;
+using Moq;
 using System.Collections.Generic;
 using System.Linq.Dynamic.Core.CustomTypeProviders;
 using System.Linq.Dynamic.Core.Parser;
 using System.Linq.Expressions;
+using System.Reflection;
+using System.Threading;
+using System.Threading.Tasks;
 using Xunit;
 
-namespace System.Linq.Dynamic.Core.Tests.Parser;
-
-public class ExpressionPromoterTests
+namespace System.Linq.Dynamic.Core.Tests.Parser
 {
-    public class SampleDto
+    public class ExpressionPromoterTests
     {
-        public Guid Data { get; set; }
-    }
+        public class SampleDto
+        {
+            public Guid data { get; set; }
+        }
 
-    private readonly Mock<IExpressionPromoter> _expressionPromoterMock;
-    private readonly Mock<IDynamicLinqCustomTypeProvider> _dynamicLinkCustomTypeProviderMock;
+        private readonly Mock<IExpressionPromoter> _expressionPromoterMock;
+        private readonly Mock<IDynamicLinkCustomTypeProvider> _dynamicLinkCustomTypeProviderMock;
 
-    public ExpressionPromoterTests()
-    {
-        _dynamicLinkCustomTypeProviderMock = new Mock<IDynamicLinqCustomTypeProvider>();
-        _dynamicLinkCustomTypeProviderMock.Setup(d => d.GetCustomTypes()).Returns(new HashSet<Type>());
-        _dynamicLinkCustomTypeProviderMock.Setup(d => d.ResolveType(It.IsAny<string>())).Returns(typeof(SampleDto));
+        public ExpressionPromoterTests()
+        {
+            _dynamicLinkCustomTypeProviderMock = new Mock<IDynamicLinkCustomTypeProvider>();
+            _dynamicLinkCustomTypeProviderMock.Setup(d => d.GetCustomTypes()).Returns(new HashSet<Type>());
+            _dynamicLinkCustomTypeProviderMock.Setup(d => d.ResolveType(It.IsAny<string>())).Returns(typeof(SampleDto));
+
+            _expressionPromoterMock = new Mock<IExpressionPromoter>();
+            _expressionPromoterMock.Setup(e => e.Promote(It.IsAny<Expression>(), It.IsAny<Type>(), It.IsAny<bool>(), It.IsAny<bool>())).Returns(Expression.Constant(Guid.NewGuid()));
+        }
+
+        [Fact]
+        public void DynamicExpressionParser_ParseLambda_WithCustomExpressionPromoter()
+        {
+            // Assign
+            var parsingConfig = new ParsingConfig()
+            {
+                AllowNewToEvaluateAnyType = true,
+                CustomTypeProvider = _dynamicLinkCustomTypeProviderMock.Object,
+                ExpressionPromoter = _expressionPromoterMock.Object
+            };
+
+            // Act
+            string query = $"new {typeof(SampleDto).FullName}(@0 as data)";
+            LambdaExpression expression = DynamicExpressionParser.ParseLambda(parsingConfig, null, query, new object[] { Guid.NewGuid().ToString() });
+            Delegate del = expression.Compile();
+            SampleDto result = (SampleDto)del.DynamicInvoke();
+
+            // Assert
+            Assert.NotNull(result);
+
+            // Verify
+            _dynamicLinkCustomTypeProviderMock.Verify(d => d.GetCustomTypes(), Times.Once);
+            _dynamicLinkCustomTypeProviderMock.Verify(d => d.ResolveType($"{typeof(SampleDto).FullName}"), Times.Once);
+
+            _expressionPromoterMock.Verify(e => e.Promote(It.IsAny<ConstantExpression>(), typeof(Guid), true, true), Times.Once);
+        }
 
-        _expressionPromoterMock = new Mock<IExpressionPromoter>();
-        _expressionPromoterMock.Setup(e => e.Promote(It.IsAny<Expression>(), It.IsAny<Type>(), It.IsAny<bool>(), It.IsAny<bool>())).Returns(Expression.Constant(Guid.NewGuid()));
+        [Fact]
+        public async Task Promote_Should_Succeed_Even_When_LiteralsCache_Is_Cleaned()
+        {
+            // Arrange
+            var parsingConfig = new ParsingConfig()
+            {
+                ConstantExpressionCacheConfig = new Core.Util.Cache.CacheConfig
+                {
+                    CleanupFrequency = TimeSpan.FromMilliseconds(500), // Run cleanup more often
+                    TimeToLive = TimeSpan.FromMilliseconds(500), // Shorten TTL to force expiration
+                    ReturnExpiredItems = false
+                }
+            };
+
+            // because the field is static only one process is setting the field,
+            // we need a way to set up because the instance is private we are not able to overwrite the configuration.
+            ConstantExpressionHelperReflection.Initiate(parsingConfig);
+
+            var constantExpressionHelper = ConstantExpressionHelperFactory.GetInstance(parsingConfig);
+            var expressionPromoter = new ExpressionPromoter(parsingConfig);
+
+            double value = 0.40;
+            string text = "0.40";
+            Type targetType = typeof(decimal);
+
+            // Step 1: Add constant to cache
+            var literalExpression = constantExpressionHelper.CreateLiteral(value, text);
+            Assert.NotNull(literalExpression); // Ensure it was added
+
+            // Step 2: Manually trigger cleanup
+            var cts = new CancellationTokenSource(500);
+            await Task.Run(async () =>
+            {
+                while (!cts.IsCancellationRequested)
+                {
+                    constantExpressionHelper.TryGetText(literalExpression, out _);
+                    await Task.Delay(50); // Give some time for cleanup to be triggered
+                }
+            });
+
+            // Ensure some cleanup cycles have passed
+            await Task.Delay(500); // Allow cache cleanup to happen
+
+            // Step 3: Attempt to promote the expression after cleanup
+            var promotedExpression = expressionPromoter.Promote(literalExpression, targetType, exact: false, true);
+
+            // Assert: Promotion should still work even if the cache was cleaned
+            promotedExpression.Should().NotBeNull(); // Ensure `Promote()` still returns a valid expression
+        }
     }
 
-    [Fact]
-    public void DynamicExpressionParser_ParseLambda_WithCustomExpressionPromoter()
+    public static class ConstantExpressionHelperReflection
     {
-        // Assign
-        var parsingConfig = new ParsingConfig()
+        private static readonly Type _constantExpressionHelperFactoryType;
+
+        static ConstantExpressionHelperReflection()
         {
-            AllowNewToEvaluateAnyType = true,
-            CustomTypeProvider = _dynamicLinkCustomTypeProviderMock.Object,
-            ExpressionPromoter = _expressionPromoterMock.Object
-        };
+            var assembly = Assembly.GetAssembly(typeof(DynamicClass))!;
 
-        // Act
-        string query = $"new {typeof(SampleDto).FullName}(@0 as Data)";
-        LambdaExpression expression = DynamicExpressionParser.ParseLambda(parsingConfig, null, query, Guid.NewGuid().ToString());
-        Delegate del = expression.Compile();
-        SampleDto result = (SampleDto)del.DynamicInvoke();
+            _constantExpressionHelperFactoryType = assembly.GetType("System.Linq.Dynamic.Core.Parser.ConstantExpressionHelperFactory")!;
+        }
 
-        // Assert
-        Assert.NotNull(result);
+        public static void Initiate(ParsingConfig parsingConfig)
+        {
+            var instance = new ConstantExpressionHelper(parsingConfig);
 
-        // Verify
-        _dynamicLinkCustomTypeProviderMock.Verify(d => d.GetCustomTypes(), Times.Once);
-        _dynamicLinkCustomTypeProviderMock.Verify(d => d.ResolveType($"{typeof(SampleDto).FullName}"), Times.Once);
+            var field = _constantExpressionHelperFactoryType.GetField("_instance", BindingFlags.NonPublic | BindingFlags.Static);
 
-        _expressionPromoterMock.Verify(e => e.Promote(It.IsAny<ConstantExpression>(), typeof(Guid), true, true), Times.Once);
+            field?.SetValue(field, instance);
+        }
     }
-}
+}