From 7e1ed96d8493e6f1c4eb7b821372e55f19d8ee94 Mon Sep 17 00:00:00 2001
From: "Alecio Furanze (Ale)" <alecio@kezero.com>
Date: Wed, 11 Dec 2024 18:58:41 +0200
Subject: [PATCH] adding concat byte extension #36

---
 src/src/extension/ByteExtension.cs  | 36 +++++++++++++++++++++++++++++
 test/extension/ByteExtensionTest.cs | 24 +++++++++++++++----
 2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/src/src/extension/ByteExtension.cs b/src/src/extension/ByteExtension.cs
index abc7a05..3dee9e1 100644
--- a/src/src/extension/ByteExtension.cs
+++ b/src/src/extension/ByteExtension.cs
@@ -1,3 +1,5 @@
+using System.Collections.Generic;
+using System.Linq;
 using System.Text;
 using ByEx = Byter.ByterExtension;
 
@@ -14,5 +16,39 @@ public static string GetString(this byte[] content, Encoding encoding)
         {
             return ByEx.IsNull(content) ? ByEx.DEFAULT_STRING_VALUE : encoding.GetString(content);
         }
+
+        public static byte[] Concat(this byte[] value, params byte[][] values)
+        {
+            return Concat(value, false, values);
+        }
+        
+        public static byte[] ConcatInverse(this byte[] value, params byte[][] values)
+        {
+            return Concat(value, true, values);
+        }
+
+        public static byte[] Concat(this byte[] value, bool invert, params byte[][] values)
+        {
+            var list = new List<byte[]> { value };
+
+            list.AddRange(values);
+
+            if (!invert || list.Count <= 1) return list.SelectMany(x => x).ToArray();
+
+            var reversed = new List<byte[]>();
+
+            var count = list.Count - 1;
+
+            while (list.Count > 0)
+            {
+                reversed.Add(list[count]);
+                list.RemoveAt(count);
+                count--;
+            }
+
+            list.Clear();
+
+            return reversed.SelectMany(x => x).ToArray();
+        }
     }
 }
\ No newline at end of file
diff --git a/test/extension/ByteExtensionTest.cs b/test/extension/ByteExtensionTest.cs
index c0bfa43..c5a427e 100644
--- a/test/extension/ByteExtensionTest.cs
+++ b/test/extension/ByteExtensionTest.cs
@@ -15,16 +15,16 @@ public void GetString()
         var utf8Bytes = BaseText.GetBytes(Encoding.UTF8);
         var utf16Bytes = BaseText.GetBytes(Encoding.Unicode);
         var utf32Bytes = BaseText.GetBytes(Encoding.UTF32);
-        
+
         Assert.Equal(BaseText, utf8Bytes.GetString(Encoding.UTF8));
         Assert.Equal(BaseText, utf16Bytes.GetString(Encoding.Unicode));
         Assert.Equal(BaseText, utf32Bytes.GetString(Encoding.UTF32));
-        
+
         Assert.NotEqual(BaseText, utf16Bytes.GetString(Encoding.UTF8));
         Assert.NotEqual(BaseText, utf32Bytes.GetString(Encoding.Unicode));
         Assert.NotEqual(BaseText, utf8Bytes.GetString(Encoding.UTF32));
     }
-    
+
     [Fact]
     public void Nullable()
     {
@@ -32,4 +32,20 @@ public void Nullable()
         Assert.Equal(result, Array.Empty<byte>().GetString());
         Assert.Equal(result, ByteExtension.GetString(null!));
     }
-}
+
+    [Fact]
+    public void Concat()
+    {
+        byte[] part1 = [1, 2, 3];
+        byte[] part2 = [4, 5, 6];
+        byte[] part3 = [7, 8, 9];
+
+        Assert.Equal([1, 2, 3, /**/ 4, 5, 6], part1.Concat(part2));
+        Assert.Equal([1, 2, 3, /**/ 4, 5, 6], part1.Concat(false, part2));
+        Assert.Equal([1, 2, 3, /**/ 4, 5, 6, /**/7, 8, 9], part1.Concat(false, part2, part3));
+
+        Assert.Equal([4, 5, 6, /**/ 1, 2, 3], part1.ConcatInverse(part2));
+        Assert.Equal([4, 5, 6, /**/ 1, 2, 3], part1.Concat(true, part2));
+        Assert.Equal([7, 8, 9, /**/ 4, 5, 6, /**/ 1, 2, 3,], part1.Concat(true, part2, part3));
+    }
+}
\ No newline at end of file