Moved all unit test files into a separate directory in preparation for splitting the project

Tests/Collections/VariegatorTest.cs

@@ -0,0 +1,87 @@
+#region Apache License 2.0
+/*
+Nuclex .NET Framework
+Copyright (C) 2002-2024 Markus Ewald / Nuclex Development Labs
+
+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.
+*/
+#endregion // Apache License 2.0
+
+#if !NO_SETS
+
+using System;
+using System.Collections.Generic;
+
+#if UNITTEST
+
+using NUnit.Framework;
+
+namespace Nuclex.Support.Collections {
+
+  /// <summary>Unit Test for the Variegator multi dictionary</summary>
+  [TestFixture]
+  internal class VariegatorTest {
+
+    /// <summary>
+    ///   Tests whether the default constructor of the reverse comparer works
+    /// </summary>
+    [Test]
+    public void InstancesCanBeCreated() {
+      new Variegator<int, string>();
+    }
+
+    /// <summary>
+    ///   Verifies that querying for a missing value leads to an exception being thrown
+    /// </summary>
+    [Test]
+    public void QueryingMissingValueThrowsException() {
+      var variegator = new Variegator<int, string>();
+      Assert.Throws<KeyNotFoundException>(
+        () => {
+          variegator.Get(123);
+        }
+      );
+    }
+
+    /// <summary>
+    ///   Verifies that the variegator resolves ambiguous matches according to its design
+    /// </summary>
+    [Test]
+    public void AmbiguityResolvesToLeastRecentValue() {
+      var variegator = new Variegator<int, string>();
+      variegator.Add(1, "one");
+      variegator.Add(1, "eins");
+
+      string first = variegator.Get(1);
+      string second = variegator.Get(1);
+
+      // The variegator should have selected the first value by random and then
+      // returned the other value on the second query
+      Assert.AreNotEqual(first, second);
+
+      // Now the variegator should return the first value again because it is
+      // the least recently used value
+      Assert.AreEqual(first, variegator.Get(1));
+
+      // Repeating the query, the second should be returned again because now
+      // it has become the least recently used value
+      Assert.AreEqual(second, variegator.Get(1));
+    }
+
+  }
+
+} // namespace Nuclex.Support.Collections
+
+#endif // UNITTEST
+
+#endif // !NO_SETS