Add basic transaction support

Tests/Tests.csproj

@@ -1,18 +1,30 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks>net6.0</TargetFrameworks>
-        <LangVersion>latest</LangVersion>
+        <TargetFramework>net7.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+
+        <IsPackable>false</IsPackable>
+
+        <RootNamespace>RocksDbSharp.Tests</RootNamespace>
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
-        <PackageReference Include="MSTest.TestAdapter" Version="2.2.8" />
-        <PackageReference Include="MSTest.TestFramework" Version="2.2.8" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2"/>
+        <PackageReference Include="MSTest.TestAdapter" Version="2.2.10"/>
+        <PackageReference Include="MSTest.TestFramework" Version="2.2.10"/>
     </ItemGroup>
 
     <ItemGroup>
         <ProjectReference Include="..\csharp\RocksDbSharp.csproj" />
     </ItemGroup>
+
+    <ItemGroup>
+      <None Remove="rocksdb.dll" />
+      <Content Include="rocksdb.dll">
+        <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      </Content>
+    </ItemGroup>
 
 </Project>

Tests/TransactionTests.cs

@@ -0,0 +1,154 @@
+namespace RocksDbSharp.Tests;
+
+[TestClass]
+public class TransactionTests
+{
+    private string? _path;
+    private TransactionDb? _db;
+
+    [TestInitialize]
+    public void TestInitialize()
+    {
+        _path = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+
+        var dbOptions = new DbOptions().SetCreateIfMissing();
+        var transactionDbOptions = new TransactionDbOptions();
+        _db = TransactionDb.Open(dbOptions, transactionDbOptions, _path);
+    }
+
+    [TestCleanup]
+    public void TestCleanup()
+    {
+        _db?.Dispose();
+        _db = null;
+
+        if (Directory.Exists(_path))
+            Directory.Delete(_path, true);
+    }
+
+    [TestMethod]
+    public void key_should_be_visible_inside_transaction_while_uncommitted()
+    {
+        // Arrange
+        const string key = "key1";
+        const string value = "value1";
+
+        using var tran = _db!.BeginTransaction();
+
+        // Act
+        tran.Put(key, value);
+        var exists = tran.HasKey(key);
+
+        // Assert
+        Assert.IsTrue(exists);
+    }
+
+    [TestMethod]
+    public void key_should_not_be_visible_outside_transaction_while_uncommitted()
+    {
+        // Arrange
+        const string key = "key1";
+        const string value = "value1";
+
+        using var tran = _db!.BeginTransaction();
+
+        // Act
+        tran.Put(key, value);
+        var exists = _db.HasKey(key);
+
+        // Assert
+        Assert.IsFalse(exists);
+    }
+
+    [TestMethod]
+    public void key_should_be_visible_outside_transaction_after_commit()
+    {
+        // Arrange
+        const string key = "key1";
+        const string value = "value1";
+
+        using var tran = _db!.BeginTransaction();
+
+        // Act
+        tran.Put(key, value);
+        tran.Commit();
+        var exists = _db.HasKey(key);
+
+        // Assert
+        Assert.IsTrue(exists);
+    }
+
+    [TestMethod]
+    public void key_should_not_be_iterable_outside_transaction_while_uncommitted()
+    {
+        // Arrange
+        const string key = "key1";
+        const string value = "value1";
+
+        using var tran = _db!.BeginTransaction();
+
+        // Act
+        tran.Put(key, value);
+        using var iterator = _db.NewIterator().SeekToFirst();
+
+        // Assert
+        Assert.AreNotEqual(key, iterator.StringKey());
+    }
+
+    [TestMethod]
+    public void key_should_be_iterable_outside_transaction_after_commit()
+    {
+        // Arrange
+        const string key = "key1";
+        const string value = "value1";
+
+        using var tran = _db!.BeginTransaction();
+
+        // Act
+        tran.Put(key, value);
+        tran.Commit();
+        using var iterator = _db.NewIterator().SeekToFirst();
+
+        // Assert
+        Assert.AreEqual(key, iterator.StringKey());
+    }
+
+    [TestMethod]
+    public void old_value_should_be_visible_outside_transaction_while_uncommitted()
+    {
+        // Arrange
+        const string key = "key";
+        const string value1 = "value1";
+        const string value2 = "value2";
+        _db!.Put(key, value1);
+
+        using var tran = _db.BeginTransaction();
+
+        // Act
+        tran.Put(key, value2);
+        var result = _db.Get(key);
+
+        // Assert
+        Assert.AreEqual(value1, result);
+    }
+
+    [TestMethod]
+    public void new_value_should_be_visible_outside_transaction_after_commit()
+    {
+        // Arrange
+        const string key = "key";
+        const string value1 = "value1";
+        const string value2 = "value2";
+        _db!.Put(key, value1);
+
+        using var tran = _db.BeginTransaction();
+
+        // Act
+        tran.Put(key, value2);
+        tran.Commit();
+        var result = _db.Get(key);
+
+        // Assert
+        Assert.AreEqual(value2, result);
+    }
+}

Tests/Usings.cs

@@ -0,0 +1 @@
+global using Microsoft.VisualStudio.TestTools.UnitTesting;