From 448656fd295a03e2efb88522c90b6a1ab62ae23a Mon Sep 17 00:00:00 2001
From: mlemanczyk <marek@lemanczyk.eu>
Date: Sat, 24 Jun 2023 23:55:01 +0200
Subject: [PATCH] IVersionedLongList<T> interface &
 RecyclableLongList.GetVersionedEnumerator added for use with foreach.

---
 Recyclable.Collections/IVersionedLongList.cs   |  7 +++++++
 .../RecyclableLongList.VersionedEnumerator.cs  | 10 +++++++---
 Recyclable.Collections/RecyclableLongList.cs   |  1 -
 .../RecyclableLongListTests.cs                 | 18 ++++++++++++++++++
 4 files changed, 32 insertions(+), 4 deletions(-)
 create mode 100644 Recyclable.Collections/IVersionedLongList.cs

diff --git a/Recyclable.Collections/IVersionedLongList.cs b/Recyclable.Collections/IVersionedLongList.cs
new file mode 100644
index 0000000..022de93
--- /dev/null
+++ b/Recyclable.Collections/IVersionedLongList.cs
@@ -0,0 +1,7 @@
+namespace Recyclable.Collections
+{
+	public interface IVersionedLongList<T> : IEnumerable<T>
+	{
+		new RecyclableLongList<T>.VersionedEnumerator GetEnumerator();
+	}
+}
diff --git a/Recyclable.Collections/RecyclableLongList.VersionedEnumerator.cs b/Recyclable.Collections/RecyclableLongList.VersionedEnumerator.cs
index bd339ae..e11b112 100644
--- a/Recyclable.Collections/RecyclableLongList.VersionedEnumerator.cs
+++ b/Recyclable.Collections/RecyclableLongList.VersionedEnumerator.cs
@@ -3,8 +3,12 @@ using System.Diagnostics.Contracts;
 
 namespace Recyclable.Collections
 {
-	public partial class RecyclableLongList<T>
+
+public partial class RecyclableLongList<T> : IVersionedLongList<T>
 	{
+		public VersionedEnumerator GetVersionedEnumerator() => new(this);
+		VersionedEnumerator IVersionedLongList<T>.GetEnumerator() => new(this);
+
 		public struct VersionedEnumerator : IEnumerator<T>
 		{
 #nullable disable
@@ -26,13 +30,13 @@ namespace Recyclable.Collections
 
 			public bool MoveNext()
 			{
-				if (_enumeratorVersion != _list._version)
+				var list = _list;
+				if (_enumeratorVersion != list._version)
 				{
 					throw new InvalidOperationException();
 				}
 
 				Contract.EndContractBlock();
-				var list = _list;
 
 				if (_currentBlockIndex < list._lastBlockWithData)
 				{
diff --git a/Recyclable.Collections/RecyclableLongList.cs b/Recyclable.Collections/RecyclableLongList.cs
index 3b069e5..90ef792 100644
--- a/Recyclable.Collections/RecyclableLongList.cs
+++ b/Recyclable.Collections/RecyclableLongList.cs
@@ -1109,7 +1109,6 @@ namespace Recyclable.Collections
 		public Enumerator GetEnumerator() => new(this);
 		IEnumerator IEnumerable.GetEnumerator() => new Enumerator(this);
 		IEnumerator<T> IEnumerable<T>.GetEnumerator() => new Enumerator(this);
-		public VersionedEnumerator GetVersionedEnumerator() => new(this);
 
 		[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
 		public int IndexOf(T item)
diff --git a/Recyclable.CollectionsTests/RecyclableLongListTests.cs b/Recyclable.CollectionsTests/RecyclableLongListTests.cs
index e2d610b..f1489a2 100644
--- a/Recyclable.CollectionsTests/RecyclableLongListTests.cs
+++ b/Recyclable.CollectionsTests/RecyclableLongListTests.cs
@@ -398,6 +398,24 @@ namespace Recyclable.CollectionsTests
 			_ = actual.Should().ContainInConsecutiveOrder(testData);
 		}
 
+		[Theory]
+		[MemberData(nameof(RecyclableLongListTestData.SourceTargetDataVariants), MemberType = typeof(RecyclableLongListTestData))]
+		public void VersionedEnumerateShouldYieldAllItemsInCorrectOrder(string testCase, IEnumerable<long> testData, long itemsCount, int targetBlockSize)
+		{
+			// Prepare
+			using var list = new RecyclableLongList<long>(testData, minBlockSize: targetBlockSize);
+
+			// Act
+			var actual = new List<long>();
+			foreach(var item in (IVersionedLongList<long>)list)
+			{
+				actual.Add(item);
+			}
+
+			// Validate
+			_ = actual.Should().ContainInConsecutiveOrder(testData);
+		}
+
 		[Fact]
 		public void IndexOfShouldNotFindAnythingWhenListEmpty()
 		{