diff --git a/test/DotRecast.Core.Test/RcStackArrayTest.cs b/test/DotRecast.Core.Test/RcStackArrayTest.cs
index 37bde51..24a8d4e 100644
--- a/test/DotRecast.Core.Test/RcStackArrayTest.cs
+++ b/test/DotRecast.Core.Test/RcStackArrayTest.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using DotRecast.Core.Collections;
 using NUnit.Framework;
 
@@ -7,47 +8,40 @@ namespace DotRecast.Core.Test;
 [Parallelizable]
 public class RcStackArrayTest
 {
-    [Test]
-    public void TestRcStackArray()
+    public List<int> RandomValues(int size)
     {
         var rand = new RcRand();
 
         // excepted values
         var list = new List<int>();
-        for (int i = 0; i < 1024; ++i)
+        for (int i = 0; i < size; ++i)
         {
             list.Add(rand.NextInt32());
         }
 
-        {
-            RcStackArray4<int> array = RcStackArray4<int>.Empty;
-            for (int i = 0; i < array.Length; ++i)
-            {
-                array[i] = list[i];
-            }
-
-            for (int i = 0; i < array.Length; ++i)
-            {
-                Assert.That(array[i], Is.EqualTo(list[i]));
-            }
-        }
-
-        {
-            RcStackArray8<int> array = RcStackArray8<int>.Empty;
-            for (int i = 0; i < array.Length; ++i)
-            {
-                array[i] = list[i];
-            }
-
-            for (int i = 0; i < array.Length; ++i)
-            {
-                Assert.That(array[i], Is.EqualTo(list[i]));
-            }
-        }
+        return list;
     }
 
-    public void Test<T>(T a)
+    [Test]
+    public void TestRcStackArray4()
     {
-        T s = a;
+        var values = RandomValues(4);
+        RcStackArray4<int> array = RcStackArray4<int>.Empty;
+        for (int i = 0; i < array.Length; ++i)
+        {
+            array[i] = values[i];
+        }
+
+        for (int i = 0; i < array.Length; ++i)
+        {
+            Assert.That(array[i], Is.EqualTo(values[i]));
+        }
+
+        Assert.That(array[^1], Is.EqualTo(values[^1]));
+
+        Assert.Throws<IndexOutOfRangeException>(() => array[-1] = 0);
+        Assert.Throws<IndexOutOfRangeException>(() => array[array.Length + 1] = 0);
+        Assert.Throws<IndexOutOfRangeException>(() => _ = array[-1]);
+        Assert.Throws<IndexOutOfRangeException>(() => _ = array[array.Length + 1]);
     }
 }
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