feat: Initial commit of WeakKeyDictionary for keeping caches of items that can not invalidate themselves

ICD.Common.Utils.Tests/Collections/WeakKeyDictionaryTest.cs

@@ -0,0 +1,158 @@
+using System;
+using ICD.Common.Utils.Collections;
+using NUnit.Framework;
+
+namespace ICD.Common.Utils.Tests.Collections
+{
+	[TestFixture]
+	public sealed class WeakKeyDictionaryTest
+	{
+		private sealed class TestClass
+		{
+		}
+
+		#region Properties
+
+		[Test]
+		public void CountTest()
+		{
+#if DEBUG
+			Assert.Inconclusive();
+			return;
+#endif
+			WeakKeyDictionary<TestClass, int> dict = new WeakKeyDictionary<TestClass, int>();
+			Assert.AreEqual(0, dict.Count);
+
+			TestClass instance = new TestClass();
+
+			dict.Add(instance, 0);
+
+			Assert.AreEqual(1, dict.Count, "Expected the added item to increase the dictionary size");
+
+			GC.Collect();
+			GC.WaitForPendingFinalizers();
+			GC.Collect();
+
+			Assert.AreEqual(1, dict.Count, "Expected the dictionary to have one uncollected item");
+
+			// Need to actually USE the instance at some point AFTER the collection, otherwise it gets optimized out
+			// and is collected prematurely.
+			// ReSharper disable once ReturnValueOfPureMethodIsNotUsed
+			instance.ToString();
+
+			// Now clear the reference to make sure the instance gets collected.
+			// ReSharper disable once RedundantAssignment
+			instance = null;
+
+			GC.Collect();
+			GC.WaitForPendingFinalizers();
+			GC.Collect();
+
+			Assert.AreEqual(0, dict.Count, "Expected the dictionary to be empty after collecting");
+		}
+
+		[Test]
+		public void KeysTest()
+		{
+			Assert.Inconclusive();
+		}
+
+		[Test]
+		public void ValuesTest()
+		{
+			Assert.Inconclusive();
+		}
+
+		[Test]
+		public void IndexerTest()
+		{
+			Assert.Inconclusive();
+		}
+
+#endregion
+
+#region Methods
+
+		[Test]
+		public void AddTest()
+		{
+			Assert.Inconclusive();
+		}
+
+		[Test]
+		public void ContainsKeyTest()
+		{
+			Assert.Inconclusive();
+		}
+
+		[Test]
+		public void RemoveTest()
+		{
+			Assert.Inconclusive();
+		}
+
+		[Test]
+		public void TryGetValueTest()
+		{
+			Assert.Inconclusive();
+		}
+
+		[Test]
+		public void ClearTest()
+		{
+			Assert.Inconclusive();
+		}
+
+		[Test]
+		public void RemoveCollectedEntries()
+		{
+#if DEBUG
+			Assert.Inconclusive();
+			return;
+#endif
+			WeakKeyDictionary<TestClass, int> dict = new WeakKeyDictionary<TestClass, int>();
+
+			dict.RemoveCollectedEntries();
+			Assert.AreEqual(0, dict.Count, "Expected new dictionary to start empty");
+
+			TestClass instance = new TestClass();
+
+			dict.Add(instance, 0);
+			dict.RemoveCollectedEntries();
+
+			Assert.AreEqual(1, dict.Count, "Expected instance to add to the dictionary count");
+
+			GC.Collect();
+			GC.WaitForPendingFinalizers();
+			GC.Collect();
+
+			dict.RemoveCollectedEntries();
+
+			Assert.AreEqual(1, dict.Count, "Expected instance to remain uncollected and stay in the dictionary");
+
+			// Need to actually USE the instance at some point AFTER the collection, otherwise it gets optimized out
+			// and is collected prematurely.
+			// ReSharper disable once ReturnValueOfPureMethodIsNotUsed
+			instance.ToString();
+
+			// Now clear the reference to make sure the instance gets collected.
+			// ReSharper disable once RedundantAssignment
+			instance = null;
+
+			GC.Collect();
+			GC.WaitForPendingFinalizers();
+			GC.Collect();
+			dict.RemoveCollectedEntries();
+
+			Assert.AreEqual(0, dict.Count, "Expected instance to be collected and removed from the dictionary");
+		}
+
+		[Test]
+		public void GetEnumeratorTest()
+		{
+			Assert.Inconclusive();
+		}
+
+#endregion
+	}
+}