Add ByteArraySearcher to CsvLib.

CsvLib.Tests/ByteArraySearcherTests.cs

@@ -0,0 +1,66 @@
+using CsvLib;
+
+namespace CvsLib;
+
+public class ByteArraySearcherTests
+{
+    [Fact]
+    public void Contains__EmptyNeedle_ReturnsTrue()
+    {
+        byte[] haystack = { 1, 2, 3, 4, 5 };
+        byte[] needle = Array.Empty<byte>();
+        ByteArraySearcher searcher = new(needle);
+
+        bool result = searcher.Contains(haystack);
+
+        Assert.True(result);
+    }
+
+    [Fact]
+    public void Contains__NeedleAtBeginning_ReturnsTrue()
+    {
+        byte[] haystack = { 1, 2, 3, 4, 5 };
+        byte[] needle = { 1, 2, 3 };
+        ByteArraySearcher searcher = new(needle);
+
+        bool result = searcher.Contains(haystack);
+
+        Assert.True(result);
+    }
+
+    [Fact]
+    public void Contains__NeedleInMiddle_ReturnsTrue()
+    {
+        byte[] haystack = { 1, 2, 3, 4, 5 };
+        byte[] needle = { 3, 4 };
+        ByteArraySearcher searcher = new(needle);
+
+        bool result = searcher.Contains(haystack);
+
+        Assert.True(result);
+    }
+
+    [Fact]
+    public void Contains__NeedleAtEnd_ReturnsTrue()
+    {
+        byte[] haystack = { 1, 2, 3, 4, 5 };
+        byte[] needle = { 4, 5 };
+        ByteArraySearcher searcher = new(needle);
+
+        bool result = searcher.Contains(haystack);
+
+        Assert.True(result);
+    }
+
+    [Fact]
+    public void Contains__NeedleNotPresent_ReturnsFalse()
+    {
+        byte[] haystack = { 1, 2, 3, 4, 5 };
+        byte[] needle = { 5, 6, 7 };
+        ByteArraySearcher searcher = new(needle);
+
+        bool result = searcher.Contains(haystack);
+
+        Assert.False(result);
+    }
+}