fix(generator): guard newer refs for netstandard2.1 codegen

Author: JasonXuDeveloper

.gitignore

@@ -10,8 +10,8 @@ src/Nino.sln.DotSettings.user
 src/Nino.Shared/Nino.Shared.csproj.user
 **/BenchmarkDotNet.Artifacts
 src/Nino.Core/.AssemblyAttributes
-src/Nino.UnitTests/build.binlog
-src/Nino.UnitTests/args.rsp
+src/Nino.UnitTests/*.binlog
+src/Nino.UnitTests/*.rsp
 
 # LLM Agent directories and configuration
 .claude/

src/Nino.Generator/BuiltInType/ArrayGenerator.cs

@@ -90,7 +90,7 @@ protected override void GenerateSerializer(ITypeSymbol typeSymbol, Writer writer
             writer.AppendLine();
 
             // Both value and reference types benefit from ref iteration - eliminates bounds checks
-            writer.AppendLine("#if !UNITY_2020_2_OR_NEWER");
+            writer.AppendLine("#if NET5_0_OR_GREATER");
             writer.AppendLine("    ref var cur = ref System.Runtime.InteropServices.MemoryMarshal.GetArrayDataReference(value);");
             writer.AppendLine("#else");
             writer.AppendLine("    ref var cur = ref value[0];");

src/Nino.Generator/BuiltInType/DictionaryGenerator.cs

@@ -114,7 +114,7 @@ protected override void GenerateSerializer(ITypeSymbol typeSymbol, Writer writer
             writer.AppendLine("        return;");
             writer.AppendLine("    }");
             writer.AppendLine("    // Iterate entries via direct ref to avoid bounds checks");
-            writer.AppendLine("#if !UNITY_2020_2_OR_NEWER");
+            writer.AppendLine("#if NET5_0_OR_GREATER");
             writer.AppendLine("    ref var entryRef = ref System.Runtime.InteropServices.MemoryMarshal.GetArrayDataReference(entries);");
             writer.AppendLine("#else");
             writer.AppendLine("    ref var entryRef = ref entries[0];");

src/Nino.Generator/BuiltInType/HashSetGenerator.cs

@@ -106,7 +106,7 @@ protected override void GenerateSerializer(ITypeSymbol typeSymbol, Writer writer
             writer.AppendLine("        return;");
             writer.AppendLine("    }");
             writer.AppendLine("    // Iterate entries via direct ref to avoid bounds checks");
-            writer.AppendLine("#if !UNITY_2020_2_OR_NEWER");
+            writer.AppendLine("#if NET5_0_OR_GREATER");
             writer.AppendLine("    ref var entryRef = ref System.Runtime.InteropServices.MemoryMarshal.GetArrayDataReference(entries);");
             writer.AppendLine("#else");
             writer.AppendLine("    ref var entryRef = ref entries[0];");

src/Nino.Generator/BuiltInType/StackGenerator.cs

@@ -108,7 +108,7 @@ protected override void GenerateSerializer(ITypeSymbol typeSymbol, Writer writer
 
             // Use ref iteration for all types to eliminate bounds checks
             writer.AppendLine("    // Stack serializes from top to bottom with ref iteration");
-            writer.AppendLine("#if !UNITY_2020_2_OR_NEWER");
+            writer.AppendLine("#if NET5_0_OR_GREATER");
             writer.AppendLine("    ref var cur = ref System.Runtime.CompilerServices.Unsafe.Add(ref System.Runtime.InteropServices.MemoryMarshal.GetArrayDataReference(array), cnt - 1);");
             writer.AppendLine("    ref var end = ref System.Runtime.CompilerServices.Unsafe.Subtract(ref System.Runtime.InteropServices.MemoryMarshal.GetArrayDataReference(array), 1);");
             writer.AppendLine("#else");

src/Nino.UnitTests/AdvancedCollectionTests.cs

@@ -43,6 +43,7 @@ public void TestNewCollectionTypes()
 
         Console.WriteLine("SortedSet tests passed!");
 
+#if NET6_0_OR_GREATER
         // Test PriorityQueue<TElement, TPriority>
         // 1. Primitive unmanaged
         PriorityQueue<int, int> priorityQueueInt = new PriorityQueue<int, int>();
@@ -80,6 +81,7 @@ public void TestNewCollectionTypes()
         Assert.AreEqual(2, priorityQueueStructResult.Count);
 
         Console.WriteLine("PriorityQueue tests passed!");
+#endif
 
         // Test SortedDictionary<TKey, TValue>
         // 1. Primitive unmanaged key and value
@@ -264,6 +266,7 @@ public void TestNewCollectionTypesComplex()
         Assert.AreEqual(1, immutableListOf2DArraysResult[0][0, 0]);
         Assert.AreEqual(8, immutableListOf2DArraysResult[1][1, 1]);
 
+#if NET6_0_OR_GREATER
         // 5. PriorityQueue with nested generic type parameters
         PriorityQueue<List<string>, int> priorityQueueNested = new PriorityQueue<List<string>, int>();
         priorityQueueNested.Enqueue(new List<string> { "a", "b" }, 2);
@@ -276,6 +279,7 @@ public void TestNewCollectionTypesComplex()
         List<string> firstItem = priorityQueueNestedResult.Dequeue();
         Assert.AreEqual(2, firstItem.Count);
         Assert.AreEqual("c", firstItem[0]); // Priority 1 comes first
+#endif
 
         // 6. ReadOnlyDictionary with complex keys and values
         Dictionary<int, ImmutableArray<TestStruct3>> innerComplexDict =

src/Nino.UnitTests/Nino.UnitTests.csproj

@@ -6,7 +6,7 @@
         <IsPackable>false</IsPackable>
         <LangVersion>10</LangVersion>
         <OutputType>Library</OutputType>
-        <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
+        <TargetFrameworks>net6.0;net8.0;netstandard2.1</TargetFrameworks>
         <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
         <ReportAnalyzer>true</ReportAnalyzer>
         <EnableNETAnalyzers>false</EnableNETAnalyzers>
@@ -24,6 +24,10 @@
     <ItemGroup>
         <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.3.0" PrivateAssets="all"/>
         <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing" Version="1.1.2" />
+        <PackageReference Include="PolySharp" Version="1.15.0">
+          <PrivateAssets>all</PrivateAssets>
+          <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+        </PackageReference>
         <PackageReference Include="System.Buffers" Version="4.6.0" />
         <PackageReference Include="System.Memory" Version="4.6.0" />
     </ItemGroup>

src/Nino.UnitTests/RefOverloadTests.cs

@@ -313,6 +313,7 @@ public void TestNewCollectionTypesRefOverload()
         Assert.IsTrue(existingSortedSet.Contains(1));
         Assert.IsFalse(existingSortedSet.Contains(10)); // Should be cleared
 
+#if NET6_0_OR_GREATER
         // Test ref overload for PriorityQueue
         PriorityQueue<string, int> priorityQueue = new PriorityQueue<string, int>();
         priorityQueue.Enqueue("first", 1);
@@ -324,6 +325,7 @@ public void TestNewCollectionTypesRefOverload()
         NinoDeserializer.Deserialize(bytes, ref existingPriorityQueue);
         Assert.AreEqual(2, existingPriorityQueue.Count);
         Assert.AreEqual("first", existingPriorityQueue.Dequeue());
+#endif
 
         // Test ref overload for SortedDictionary
         SortedDictionary<int, string> sortedDict = new SortedDictionary<int, string>

src/Nino.UnitTests/TestClass.cs

@@ -247,7 +247,11 @@ namespace Nino.UnitTests
 
         public TestPrivateMemberClass()
         {
+#if NET6_0_OR_GREATER
             Id = Random.Shared.Next();
+#else
+            Id = new Random().Next();
+#endif
         }
     }