fix: handle InvocationExpression pattern for MemoryExtensions.Contains (.NET 10)

Mindbox.Data.Linq.Tests/SqlGeneration/ArrayContainsTranslationTests.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Data.Linq;
 using System.Linq;
+using System.Linq.Expressions;
+using System.Reflection;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 namespace Mindbox.Data.Linq.Tests
@@ -9,6 +11,10 @@ namespace Mindbox.Data.Linq.Tests
 	/// Tests that array.Contains(value) in LINQ queries is correctly translated to SQL IN clause.
 	/// In .NET 10, the C# compiler generates MemoryExtensions.Contains(ReadOnlySpan, value)
 	/// for this pattern instead of Enumerable.Contains — this must produce the same SQL.
+	/// Two compiler patterns exist:
+	/// 1. MethodCallExpression(op_Implicit, array) — simple closure capture
+	/// 2. InvocationExpression(ConstantExpression(delegate), []) — pre-compiled closure
+	/// Both must be handled.
 	/// </summary>
 	[TestClass]
 	public class ArrayContainsTranslationTests
@@ -32,6 +38,58 @@ public void ArrayContains_TranslatesToSqlIn()
 				command.CommandText);
 		}
 
+		/// <summary>
+		/// Directly constructs the InvocationExpression(ConstantExpression(delegate), []) pattern
+		/// using Expression API — guaranteed to exercise Pattern 2 regardless of compiler version.
+		/// The MemoryExtensions.Contains call is built by hand with a pre-compiled zero-arg delegate
+		/// as the span argument, matching exactly what .NET 10 generates in nested closure contexts.
+		/// </summary>
+		[TestMethod]
+		public void ArrayContains_InvocationExpressionPattern_TranslatesToSqlIn()
+		{
+			var ids = new[] { 1, 2, 3 };
+
+			// Build MemoryExtensions.Contains<int>(ReadOnlySpan<int>, int) method
+			var containsMethod = typeof(MemoryExtensions)
+				.GetMethods(BindingFlags.Public | BindingFlags.Static)
+				.Single(m => m.Name == "Contains"
+					&& m.IsGenericMethod
+					&& m.GetParameters() is [{ ParameterType: var p0 }, { ParameterType: { IsGenericParameter: true } }]
+					&& p0.IsGenericType
+					&& p0.GetGenericTypeDefinition() == typeof(ReadOnlySpan<>))
+				.MakeGenericMethod(typeof(int));
+
+			// Build op_Implicit: int[] → ReadOnlySpan<int>
+			var opImplicit = typeof(ReadOnlySpan<int>)
+				.GetMethod("op_Implicit", new[] { typeof(int[]) });
+
+			// Pattern 2: the compiler pre-compiles the implicit conversion into a zero-arg delegate
+			// InvocationExpression(ConstantExpression(Func<ReadOnlySpan<int>>), [])
+			// Build: Func<ReadOnlySpan<int>> spanFactory = () => op_Implicit(ids)
+			var spanFactoryBody = Expression.Call(opImplicit, Expression.Constant(ids));
+			var spanFactory = Expression.Lambda(spanFactoryBody).Compile();
+			var spanExpr = Expression.Invoke(Expression.Constant(spanFactory));
+
+			// Build: WHERE t.Id IN (ids) via MemoryExtensions.Contains(spanExpr, t.Id)
+			var tParam = Expression.Parameter(typeof(SimpleEntity), "t");
+			var idMember = Expression.Property(tParam, nameof(SimpleEntity.Id));
+			var containsCall = Expression.Call(containsMethod, spanExpr, idMember);
+			var predicate = Expression.Lambda<Func<SimpleEntity, bool>>(containsCall, tParam);
+
+			using var connection = new DbConnectionStub();
+			using var context = new DataContext(connection);
+
+			var query = context.GetTable<SimpleEntity>().Where(predicate);
+
+			using var command = context.GetCommand(query);
+
+			Assert.AreEqual(
+				"SELECT [t0].[Id], [t0].[Discriminator], [t0].[X]" + Environment.NewLine +
+				"FROM [SimpleTable] AS [t0]" + Environment.NewLine +
+				"WHERE [t0].[Id] IN (@p0, @p1, @p2)",
+				command.CommandText);
+		}
+
 		[TestMethod]
 		public void ArrayContains_EmptyArray_TranslatesToFalse()
 		{

Mindbox.Data.Linq/Mindbox.Data.Linq.csproj

@@ -8,7 +8,7 @@
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <IncludeSymbols>true</IncludeSymbols>
     <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-    <PackageVersion>10.8.0$(VersionTag)</PackageVersion>
+    <PackageVersion>10.8.1$(VersionTag)</PackageVersion>
     <NoWarn>SYSLIB0003;SYSLIB0011</NoWarn>
   </PropertyGroup>
 

Mindbox.Data.Linq/SqlClient/Query/QueryConverter.cs

@@ -1774,6 +1774,54 @@ private SqlExpression GetAggregate(SqlNodeType aggType, Type clrType, SqlExpress
             return new SqlUnary(aggType, clrType, sqlType, exp, this.dominatingExpression);
         }
 
+        /// <summary>
+        /// Searches for an array of the given type in a delegate's closure.
+        /// Handles direct T[] fields (display class) and Object[] fields (runtime Closure),
+        /// including delegates nested inside Object[] fields (up to depth 3).
+        /// </summary>
+        private static object FindArrayInClosure(object target, Type arrayType, int depth = 0) {
+            if (target == null || depth > 3) {
+                return null;
+            }
+            foreach (var f in target.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)) {
+                var val = f.GetValue(target);
+                if (val?.GetType() == arrayType) {
+                    return val;
+                }
+                if (val is object[] items) {
+                    foreach (var item in items) {
+                        if (item?.GetType() == arrayType) {
+                            return item;
+                        }
+                        if (item is Delegate nested && nested.Target != null) {
+                            var found = FindArrayInClosure(nested.Target, arrayType, depth + 1);
+                            if (found != null) {
+                                return found;
+                            }
+                        }
+                    }
+                }
+            }
+            return null;
+        }
+
+        private static Expression TryExtractArrayFromSpanExpression(Expression spanExpr) {
+            if (spanExpr is MethodCallExpression { Arguments: [var arrayExpr] }) {
+                return arrayExpr;
+            }
+
+            if (spanExpr is InvocationExpression { Arguments.Count: 0, Expression: ConstantExpression { Value: Delegate { Target: { } target } } }
+                && spanExpr.Type.GetGenericArguments() is [var elementType]) {
+                var arrayType = elementType.MakeArrayType();
+                var array = FindArrayInClosure(target, arrayType);
+                if (array != null) {
+                    return Expression.Constant(array, arrayType);
+                }
+            }
+
+            return null;
+        }
+
         private SqlNode VisitContains(Expression sequence, Expression value) {
             Type elemType = TypeSystem.GetElementType(sequence.Type);
             SqlNode seqNode = this.Visit(sequence);
@@ -1880,15 +1928,19 @@ private SqlNode VisitMethodCall(MethodCallExpression mc) {
                     return this.VisitSequenceOperatorCall(mc);
                 }
                 // In .NET 10, array.Contains(value) in expression trees compiles to
-                // MemoryExtensions.Contains(ReadOnlySpan<T>.op_Implicit(array), value).
-                // Translate the same as Enumerable.Contains(array, value).
+                // MemoryExtensions.Contains(ReadOnlySpan<T> span, value).
+                // Two compiler patterns exist for the span argument:
+                //   1. MethodCallExpression(op_Implicit, [array]) — simple local capture
+                //   2. InvocationExpression(ConstantExpression(pre_compiled_delegate), []) — nested closure
+                // Both must be unwrapped to extract the underlying array for SQL IN translation.
                 else if (mc.Method.DeclaringType == typeof(MemoryExtensions)
                     && mc.Method.Name == "Contains"
-                    && mc.Arguments[0] is MethodCallExpression spanConversion
-                    && spanConversion.Method.ReturnType is { IsGenericType: true } returnType
-                    && returnType.GetGenericTypeDefinition() == typeof(ReadOnlySpan<>)
-                    && spanConversion.Arguments.Count == 1) {
-                    return this.VisitContains(spanConversion.Arguments[0], mc.Arguments[1]);
+                    && mc.Arguments[0].Type is { IsGenericType: true } spanType
+                    && spanType.GetGenericTypeDefinition() == typeof(ReadOnlySpan<>)) {
+                    var arrayExpr = TryExtractArrayFromSpanExpression(mc.Arguments[0]);
+                    if (arrayExpr != null) {
+                        return this.VisitContains(arrayExpr, mc.Arguments[1]);
+                    }
                 }
                 else if (IsDataManipulationCall(mc)) {
                     return this.VisitDataManipulationCall(mc);