[unity]fix: 修复 C# 侧 Nullable<T>（如 Nullable<bool>）无法正确传入 js

GeneralSetterManager.GetTranslateFunc 未处理 Nullable<T>，反射设置
Nullable 类型字段/属性时会拿到错误（或null）的转换函数。
与 GeneralGetterManager 已有的 nullable 处理对齐：对 Nullable<T>
取 underlying type 的转换函数并包装一层 null -> SetNull 的处理，
结果按 underlying type 缓存。

Author: chexiongsheng

unity/Assets/core/upm/Runtime/Src/Default/Translator/DataTranslate.cs

@@ -390,6 +390,7 @@ public static JsValueType GetJsTypeMask(Type type)
     public class GeneralSetterManager
     {
         private Dictionary<Type, GeneralSetter> generalSetterMap = new Dictionary<Type, GeneralSetter>();
+        private Dictionary<Type, GeneralSetter> nullableTypeGeneralGetterMap = new Dictionary<Type, GeneralSetter>();
 
         public GeneralSetterManager()
         {
@@ -500,7 +501,7 @@ private static void GenericDelegateTranslator(int jsEnvIdx, IntPtr isolate, ISet
         }
 
         private static void JSObjectTranslator(int jsEnvIdx, IntPtr isolate, ISetValueToJs setValueApi, IntPtr holder, object obj)
-        {
+        {
             var jsObj = obj as JSObject;
             if (jsObj == null || jsObj.jsEnv == null || !jsObj.jsEnv.CheckLiveness(false) || jsObj.jsEnv.Idx != jsEnvIdx)
             {
@@ -579,19 +580,48 @@ private GeneralSetter MakeTranslateFunc(Type type)
             }
         }
 
+        GeneralSetter MakeNullableTranslateFunc(GeneralSetter jvt)
+        {
+            return (int jsEnvIdx, IntPtr isolate, ISetValueToJs setValueApi, IntPtr holder, object obj) =>
+            {
+                if (obj == null)
+                {
+                    setValueApi.SetNull(isolate, holder);
+                }
+                else
+                {
+                    jvt(jsEnvIdx, isolate, setValueApi, holder, obj);
+                }
+            };
+        }
+
         public GeneralSetter GetTranslateFunc(Type type)
         {
             if (type.IsByRef) return GetTranslateFunc(type.GetElementType());
 
-            if (type.IsEnum) return GetTranslateFunc(Enum.GetUnderlyingType(type));
-
-            GeneralSetter jvt;
-            if (!generalSetterMap.TryGetValue(type, out jvt))
+            Type underlyingType = Nullable.GetUnderlyingType(type);
+            if (underlyingType != null)
             {
-                jvt = MakeTranslateFunc(type);
-                generalSetterMap.Add(type, jvt);
+                GeneralSetter jvt;
+                if (!nullableTypeGeneralGetterMap.TryGetValue(underlyingType, out jvt))
+                {
+                    jvt = MakeNullableTranslateFunc(GetTranslateFunc(underlyingType));
+                    nullableTypeGeneralGetterMap.Add(underlyingType, jvt);
+                }
+                return jvt;
+            }
+            else
+            {
+                if (type.IsEnum) return GetTranslateFunc(Enum.GetUnderlyingType(type));
+
+                GeneralSetter jvt;
+                if (!generalSetterMap.TryGetValue(type, out jvt))
+                {
+                    jvt = MakeTranslateFunc(type);
+                    generalSetterMap.Add(type, jvt);
+                }
+                return jvt;
             }
-            return jvt;
         }
 
         public void RegisterSetter(Type type, GeneralSetter generalSetter)

unity/test/Src/Cases/CrossLang/CrossLangTest.cs

@@ -654,6 +654,8 @@ public TestStruct? nullableNativeStructTestProp
             set { _nullableNativeStructTestProp = value; }
         }
         public static TestStruct? nullableNativeStructTestFieldStatic = default(TestStruct);
+        public static bool? nullableBoolStatic = null;
+        public static int? nullableIntStatic = null;
         protected static TestStruct? _nullableNativeStructTestPropStatic = default(TestStruct);
         public static TestStruct? nullableNativeStructTestPropStatic
         {
@@ -2037,5 +2039,45 @@ public void StaticFeildTest()
             Assert.False(StaticFeildTestHelper.Field1);
         }
 
+        [Test]
+        public void TestNullableBool()
+        {
+            var jsEnv = UnitTestEnv.GetEnv();
+            jsEnv.Eval(@"
+                (function() {
+                    const { $ref, $unref } = puer;
+                    const TestHelper = CS.Puerts.UnitTest.TestHelper;
+                    const AssertAndPrint = CS.Puerts.UnitTest.TestHelper.AssertAndPrint;
+                    console.log(typeof TestHelper.nullableBoolStatic)
+                    AssertAndPrint('TestHelper.nullableBoolStatic', TestHelper.nullableBoolStatic === null);
+                    TestHelper.nullableBoolStatic = true
+                    console.log(TestHelper.nullableBoolStatic, console.log(typeof TestHelper.nullableBoolStatic))
+                    AssertAndPrint('TestHelper.nullableBoolStatic', TestHelper.nullableBoolStatic == true);
+                    TestHelper.nullableBoolStatic = false
+                    AssertAndPrint('TestHelper.nullableBoolStatic', TestHelper.nullableBoolStatic === false);
+                })()
+            ");
+        }
+
+        [Test]
+        public void TestNullableInt()
+        {
+            var jsEnv = UnitTestEnv.GetEnv();
+            jsEnv.Eval(@"
+                (function() {
+                    const { $ref, $unref } = puer;
+                    const TestHelper = CS.Puerts.UnitTest.TestHelper;
+                    const AssertAndPrint = CS.Puerts.UnitTest.TestHelper.AssertAndPrint;
+                    console.log(typeof TestHelper.nullableIntStatic)
+                    AssertAndPrint('TestHelper.nullableIntStatic', TestHelper.nullableIntStatic === null);
+                    TestHelper.nullableIntStatic = 2
+                    console.log(TestHelper.nullableIntStatic)
+                    AssertAndPrint('TestHelper.nullableIntStatic', TestHelper.nullableIntStatic == 2);
+                    TestHelper.nullableIntStatic = 3
+                    AssertAndPrint('TestHelper.nullableIntStatic', TestHelper.nullableIntStatic === 3);
+                })()
+            ");
+        }
+
     }
 }