Initialize CBDD solution and add a .NET-focused gitignore for generated artifacts.

tests/CBDD.Tests/CursorTests.cs

@@ -0,0 +1,107 @@
+using ZB.MOM.WW.CBDD.Core.Storage;
+using ZB.MOM.WW.CBDD.Core.Indexing;
+using ZB.MOM.WW.CBDD.Bson;
+using Xunit;
+
+namespace ZB.MOM.WW.CBDD.Tests;
+
+public class CursorTests : IDisposable
+{
+    private readonly string _testFile;
+    private readonly StorageEngine _storage;
+    private readonly BTreeIndex _index;
+
+    public CursorTests()
+    {
+        _testFile = Path.Combine(Path.GetTempPath(), $"docdb_cursor_test_{Guid.NewGuid()}.db");
+        _storage = new StorageEngine(_testFile, PageFileConfig.Default);
+
+        var options = IndexOptions.CreateBTree("test");
+        _index = new BTreeIndex(_storage, options);
+
+        SeedData();
+    }
+
+    private void SeedData()
+    {
+        var txnId = _storage.BeginTransaction().TransactionId;
+
+        // Insert 10, 20, 30
+        _index.Insert(IndexKey.Create(10), new DocumentLocation(1, 0), txnId);
+        _index.Insert(IndexKey.Create(20), new DocumentLocation(2, 0), txnId);
+        _index.Insert(IndexKey.Create(30), new DocumentLocation(3, 0), txnId);
+
+        _storage.CommitTransaction(txnId);
+    }
+
+    [Fact]
+    public void MoveToFirst_ShouldPositionAtFirst()
+    {
+        using var cursor = _index.CreateCursor(0);
+        cursor.MoveToFirst().ShouldBeTrue();
+        cursor.Current.Key.ShouldBe(IndexKey.Create(10));
+    }
+
+    [Fact]
+    public void MoveToLast_ShouldPositionAtLast()
+    {
+        using var cursor = _index.CreateCursor(0);
+        cursor.MoveToLast().ShouldBeTrue();
+        cursor.Current.Key.ShouldBe(IndexKey.Create(30));
+    }
+
+    [Fact]
+    public void MoveNext_ShouldTraverseForward()
+    {
+        using var cursor = _index.CreateCursor(0);
+        cursor.MoveToFirst();
+
+        cursor.MoveNext().ShouldBeTrue();
+        cursor.Current.Key.ShouldBe(IndexKey.Create(20));
+
+        cursor.MoveNext().ShouldBeTrue();
+        cursor.Current.Key.ShouldBe(IndexKey.Create(30));
+
+        cursor.MoveNext().ShouldBeFalse(); // End
+    }
+
+    [Fact]
+    public void MovePrev_ShouldTraverseBackward()
+    {
+        using var cursor = _index.CreateCursor(0);
+        cursor.MoveToLast();
+
+        cursor.MovePrev().ShouldBeTrue();
+        cursor.Current.Key.ShouldBe(IndexKey.Create(20));
+
+        cursor.MovePrev().ShouldBeTrue();
+        cursor.Current.Key.ShouldBe(IndexKey.Create(10));
+
+        cursor.MovePrev().ShouldBeFalse(); // Start
+    }
+
+    [Fact]
+    public void Seek_ShouldPositionExact_OrNext()
+    {
+        using var cursor = _index.CreateCursor(0);
+
+        // Exact
+        cursor.Seek(IndexKey.Create(20)).ShouldBeTrue();
+        cursor.Current.Key.ShouldBe(IndexKey.Create(20));
+
+        // Non-exact (15 -> should land on 20)
+        cursor.Seek(IndexKey.Create(15)).ShouldBeFalse();
+        cursor.Current.Key.ShouldBe(IndexKey.Create(20));
+
+        // Non-exact (35 -> should be invalid/end)
+        cursor.Seek(IndexKey.Create(35)).ShouldBeFalse();
+        // Current should throw invalid
+        Should.Throw<InvalidOperationException>(() => cursor.Current);
+    }
+
+    public void Dispose()
+    {
+        _storage.Dispose();
+        if (File.Exists(_testFile)) File.Delete(_testFile);
+    }
+}