chore: import upstream snapshot with attribution

2026-07-13 13:02:50 +08:00
commit 0fc60fdcb1
5008 changed files with 910633 additions and 0 deletions
@@ -0,0 +1,156 @@
+/*
+ * QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
+ * Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+
+using Moq;
+using System.IO;
+using NUnit.Framework;
+using System.Collections.Generic;
+using QuantConnect.Lean.Engine.DataFeeds.Enumerators;
+
+namespace QuantConnect.Tests.Engine.DataFeeds.Enumerators
+{
+    [TestFixture]
+    public class RefreshEnumeratorTests
+    {
+        [Test]
+        public void StaleFileHandleException()
+        {
+            var fakeEnumerator = new Mock<IEnumerator<int?>>();
+            fakeEnumerator.Setup(e => e.MoveNext()).Throws(new IOException("stale file handle"));
+            fakeEnumerator.Setup(e => e.Dispose()).Verifiable();
+            var refresher = new RefreshEnumerator<int?>(() => fakeEnumerator.Object);
+
+            // does not throw exception but disposes of enumerator
+            refresher.MoveNext();
+
+            fakeEnumerator.Verify(enumerator => enumerator.Dispose(), Times.Once);
+
+            refresher.Dispose();
+        }
+
+        [Test]
+        public void RefreshesEnumeratorOnFirstMoveNext()
+        {
+            var refreshed = false;
+            var refresher = new RefreshEnumerator<int?>(() =>
+            {
+                refreshed = true;
+                return new List<int?>().GetEnumerator();
+            });
+
+            refresher.MoveNext();
+            Assert.IsTrue(refreshed);
+
+            refresher.Dispose();
+        }
+
+        [Test]
+        public void MoveNextReturnsTrueWhenUnderlyingEnumeratorReturnsFalse()
+        {
+            var refresher = new RefreshEnumerator<int?>(() => new List<int?>().GetEnumerator());
+            Assert.IsTrue(refresher.MoveNext());
+
+            refresher.Dispose();
+        }
+
+        [Test]
+        public void CurrentIsDefault_T_WhenUnderlyingEnumeratorReturnsFalse()
+        {
+            var refresher = new RefreshEnumerator<int?>(() => new List<int?>().GetEnumerator());
+            refresher.MoveNext();
+            Assert.AreEqual(default(int?), refresher.Current);
+
+            refresher.Dispose();
+        }
+
+        [Test]
+        public void UnderlyingEnumeratorDisposed_WhenUnderlyingEnumeratorReturnsFalse()
+        {
+            var fakeEnumerator = new Mock<IEnumerator<int?>>();
+            fakeEnumerator.Setup(e => e.MoveNext()).Returns(false);
+            fakeEnumerator.Setup(e => e.Dispose()).Verifiable();
+            var refresher = new RefreshEnumerator<int?>(() => fakeEnumerator.Object);
+            refresher.MoveNext();
+
+            fakeEnumerator.Verify(enumerator => enumerator.Dispose(), Times.Once);
+
+            refresher.Dispose();
+        }
+
+        [Test]
+        public void DisposeCallsUnderlyingDispose()
+        {
+            var fakeEnumerator = new Mock<IEnumerator<int?>>();
+            fakeEnumerator.Setup(e => e.MoveNext()).Returns(true);
+            fakeEnumerator.Setup(e => e.Dispose()).Verifiable();
+            var refresher = new RefreshEnumerator<int?>(() => fakeEnumerator.Object);
+            refresher.MoveNext();
+            refresher.Dispose();
+
+            fakeEnumerator.Verify(enumerator => enumerator.Dispose(), Times.Once);
+
+            refresher.Dispose();
+        }
+
+        [Test]
+        public void ResetCallsUnderlyingReset()
+        {
+            var fakeEnumerator = new Mock<IEnumerator<int?>>();
+            fakeEnumerator.Setup(e => e.MoveNext()).Returns(true);
+            fakeEnumerator.Setup(e => e.Reset()).Verifiable();
+            var refresher = new RefreshEnumerator<int?>(() => fakeEnumerator.Object);
+            refresher.MoveNext();
+            refresher.Reset();
+
+            fakeEnumerator.Verify(enumerator => enumerator.Reset(), Times.Once);
+
+            refresher.Dispose();
+        }
+
+        [Test]
+        public void RefreshesAfterMoveNextReturnsFalse()
+        {
+            var refreshCount = 0;
+            var list = new List<int?> {1, 2};
+            var refresher = new RefreshEnumerator<int?>(() =>
+            {
+                refreshCount++;
+                return list.GetEnumerator();
+            });
+
+            Assert.IsTrue(refresher.MoveNext());
+            Assert.AreEqual(1, refreshCount);
+            Assert.AreEqual(1, refresher.Current);
+
+            Assert.IsTrue(refresher.MoveNext());
+            Assert.AreEqual(1, refreshCount);
+            Assert.AreEqual(2, refresher.Current);
+
+            Assert.IsTrue(refresher.MoveNext());
+            Assert.AreEqual(1, refreshCount);
+            Assert.AreEqual(default(int?), refresher.Current);
+
+            Assert.IsTrue(refresher.MoveNext());
+            Assert.AreEqual(2, refreshCount);
+            Assert.AreEqual(1, refresher.Current);
+
+            Assert.IsTrue(refresher.MoveNext());
+            Assert.AreEqual(2, refreshCount);
+            Assert.AreEqual(2, refresher.Current);
+
+            refresher.Dispose();
+        }
+    }
+}