Add Preserve to constructors. Clone members to fix bug on IL2CPP

Author: yutopp

Packages/net.yutopp.vjson/Runtime/Schema/JsonSchema.cs

@@ -261,6 +261,7 @@ public JsonSchemaAttribute()
         {
         }
 
+        [Preserve]
         public JsonSchemaAttribute(bool b)
         {
             if (!b)
@@ -381,7 +382,7 @@ public static JsonSchemaAttribute CreateFromType(Type ty, JsonSchemaRegistry reg
                 reg = new JsonSchemaRegistry();
             }
 
-            var schema = TypeHelper.GetCustomAttribute<JsonSchemaAttribute>(ty);
+            var schema = (JsonSchemaAttribute) TypeHelper.GetCustomAttribute<JsonSchemaAttribute>(ty)?.MemberwiseClone(); // On IL2CPP, returns same instance, thus call MemberwiseClone.
             if (schema == null)
             {
                 schema = new JsonSchemaAttribute();

Packages/net.yutopp.vjson/Tests/Runtime/Schema/SchemaTest.cs

@@ -80,6 +80,11 @@ public void SchemaFormatTest(Type ty, string expected)
             Assert.AreEqual(expected, schema.ToString());
         }
 
+        public abstract class Gb2 {}
+
+        [JsonSchema(Id = "g2")]
+        public sealed class G2 : Gb2 {}
+
         public static object[] SchemaStringArgs = new object[] {
             new object[] {
                 typeof(int),
@@ -241,6 +246,16 @@ public void SchemaFormatTest(Type ty, string expected)
                 typeof(ValidatorWithSerializerTests.CustomTag<float>),
                 "{\"type\":\"number\",\"minimum\":0}",
             },
+            // ↓ Run same testcases twice, it will be broken on IL2CPP. Thus added as test cases.
+            new object[] {
+                typeof(G2),
+                @"{""$id"":""g2"",""type"":""object"",""properties"":{},""allOf"":[{""$ref"":""VJson.Schema.UnitTests.JsonSchemaFormatTests+Gb2""}]}",
+            },
+            new object[] {
+                typeof(G2),
+                @"{""$id"":""g2"",""type"":""object"",""properties"":{},""allOf"":[{""$ref"":""VJson.Schema.UnitTests.JsonSchemaFormatTests+Gb2""}]}",
+            },
+            // ↑
         };
     }