From 3e6a5c0ac935333adc818a04c1fbd5e1dad66741 Mon Sep 17 00:00:00 2001
From: Petr Ilin <hevav@hevav.dev>
Date: Sun, 3 Sep 2023 01:35:37 +0300
Subject: [PATCH] Fix AbstractReader#readCollectionByType

---
 .../serializer/language/reader/AbstractReader.java |  4 ++--
 .../elytrium/serializer/utils/GenericUtils.java    | 14 ++++++++++++++
 .../net/elytrium/serializer/SerializerTest.java    |  2 +-
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/main/java/net/elytrium/serializer/language/reader/AbstractReader.java b/src/main/java/net/elytrium/serializer/language/reader/AbstractReader.java
index 78cd4f9..c521dc0 100644
--- a/src/main/java/net/elytrium/serializer/language/reader/AbstractReader.java
+++ b/src/main/java/net/elytrium/serializer/language/reader/AbstractReader.java
@@ -297,9 +297,9 @@ private Collection<Object> readCollectionByType(Field owner, Type type, Class<?>
         } catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
           throw new SerializableReadException(e);
         }
-      } else if (Collection.class.isAssignableFrom(owner.getType())) {
+      } else {
         try {
-          Constructor<?> constructor = owner.getType().getDeclaredConstructor();
+          Constructor<?> constructor = GenericUtils.unwrapClassParameterizedType(type).getDeclaredConstructor();
           constructor.setAccessible(true);
           return this.readCollection(owner, (Collection<Object>) constructor.newInstance(), collectionEntryType);
         } catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
diff --git a/src/main/java/net/elytrium/serializer/utils/GenericUtils.java b/src/main/java/net/elytrium/serializer/utils/GenericUtils.java
index 3e6fd12..f4d6c77 100644
--- a/src/main/java/net/elytrium/serializer/utils/GenericUtils.java
+++ b/src/main/java/net/elytrium/serializer/utils/GenericUtils.java
@@ -23,6 +23,20 @@
 
 public class GenericUtils {
 
+  public static Class<?> unwrapClassParameterizedType(Type type) {
+    if (type instanceof ParameterizedType parameterizedType) {
+      if (parameterizedType.getRawType() instanceof Class<?> clazz) {
+        return clazz;
+      } else {
+        throw new IllegalArgumentException("Can only unwrap Class<?> from ParameterizedType");
+      }
+    } else if (type instanceof Class<?> clazz) {
+      return clazz;
+    } else {
+      throw new IllegalArgumentException("Can only unwrap Class<?> or ParameterizedType of Class<?>");
+    }
+  }
+
   public static Type getParameterTypeFromSuperclass(Class<?> parent, Type type, Type superclass, int searchIndex) {
     Type superclassType = GenericUtils.getParameterTypeOrNull(parent, superclass, searchIndex);
     if (superclassType instanceof TypeVariable<?> typeVariable && type instanceof ParameterizedType parameterizedType) {
diff --git a/src/test/java/net/elytrium/serializer/SerializerTest.java b/src/test/java/net/elytrium/serializer/SerializerTest.java
index 5dc4bc4..7d1949f 100644
--- a/src/test/java/net/elytrium/serializer/SerializerTest.java
+++ b/src/test/java/net/elytrium/serializer/SerializerTest.java
@@ -348,7 +348,7 @@ public String deserialize(String from) {
     @MapType(Int2ObjectLinkedOpenHashMap.class)
     public Int2ObjectMap<String> int2StringMapFastUtil2 = new Int2ObjectLinkedOpenHashMap<>(new int[] { 1, 15555, 44 }, new String[] { "v1", "v2", "v3" });
 
-    public final/*TODO non final*/ Int2ObjectLinkedOpenHashMap<LongArrayList> int2LongListMapFastUtil = new Int2ObjectLinkedOpenHashMap<>(
+    public Int2ObjectLinkedOpenHashMap<LongArrayList> int2LongListMapFastUtil = new Int2ObjectLinkedOpenHashMap<>(
         new int[] { 1, -15555 },
         new LongArrayList[] { LongArrayList.of(1, 2, -3, 4), LongArrayList.of(3, 2, -3, 4) }
     );