feat: net8.0 target, MemoryExtensions.Contains support in SQL translator

[korchak-aleksandr]

Summary

Main fix: MemoryExtensions.Contains support in QueryConverter

In .NET 10, array.Contains(value) in LINQ expression trees compiles to MemoryExtensions.Contains(ReadOnlySpan<T>.op_Implicit(array), value) instead of Enumerable.Contains(array, value). This caused NotSupportedException when LINQ-to-SQL tried to translate such queries.

Added handling in QueryConverter.VisitMethodCall to recognize this pattern and translate it to a SQL IN clause — the same way Enumerable.Contains is handled:

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]);
}

The check matches any conversion to ReadOnlySpan<T> by return type rather than by method name (op_Implicit), making it robust against future compiler changes.

Infrastructure

• Added Directory.Build.props: TargetFramework=net8.0, LangVersion=12
• Added Directory.Packages.props: centralized package versions
• Added README.md

Package updates

Package	Before	After
TargetFramework	netstandard2.0	net8.0
PackageVersion	10.7.2	10.8.0
Microsoft.Data.SqlClient	5.1.0	6.1.4
Mindbox.Expressions	3.3.0	3.3.1
Microsoft.NET.Test.Sdk	17.4.1	18.3.0
MSTest.TestAdapter/Framework	3.0.2	3.11.1
Moq	4.18.4	4.20.72
Removed BCL packages	System.Reflection.Emit, System.Runtime, System.Runtime.Extensions	—

System.Security.Permissions kept (required for SecurityUtils.cs); SYSLIB0003 and SYSLIB0011 suppressed — CAS is a no-op on .NET 5+ and BinaryFormatter is a legacy path.

Tests

• Tests now multi-target net8.0;net10.0 — same suite runs on both runtimes
• Added ArrayContainsTranslationTests with two cases:
  • ArrayContains_TranslatesToSqlIn — verifies WHERE Id IN (@p0, @p1, @p2) on both .NET 8 and .NET 10
  • ArrayContains_EmptyArray_TranslatesToFalse — verifies WHERE 0 = 1
• CI updated to install both .NET 8 and .NET 10 SDKs

Test plan

• dotnet build — 0 errors, 0 warnings
• dotnet test — 62 passed, 17 skipped, 0 failed (net8.0 + net10.0)