1024 fix unit normalization for quantity units such as ucum and calendar date units

Cql/CoreTests/CqlDateTests.cs

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2025, Firely, NCQA and contributors
+ * See the file CONTRIBUTORS for details.
+ *
+ * This file is licensed under the BSD 3-Clause license
+ * available at https://raw.githubusercontent.com/FirelyTeam/firely-cql-sdk/main/LICENSE
+ */
+
+#nullable enable
+using Hl7.Cql.Iso8601;
+using Hl7.Cql.Primitives;
+
+namespace CoreTests;
+
+[TestClass]
+[TestCategory("UnitTest")]
+public class CqlDateTests
+{
+    [TestMethod]
+    public void Add_Years()
+    {
+        var date = new CqlDate(2020, 1, 1);
+        var quantity = new CqlQuantity(2, "year");
+        var result = date.Add(quantity);
+        Assert.AreEqual(new CqlDate(2022, 1, 1), result);
+    }
+
+    [TestMethod]
+    public void Add_Months()
+    {
+        var date = new CqlDate(2020, 1, 31);
+        var quantity = new CqlQuantity(1, "month");
+        var result = date.Add(quantity);
+        Assert.AreEqual(new CqlDate(2020, 2, 29), result); // Leap year
+    }
+
+    [TestMethod]
+    public void Add_Days()
+    {
+        var date = new CqlDate(2020, 2, 27);
+        var quantity = new CqlQuantity(2, "day");
+        var result = date.Add(quantity);
+        Assert.AreEqual(new CqlDate(2020, 2, 29), result);
+    }
+
+    [TestMethod]
+    public void Subtract_Years()
+    {
+        var date = new CqlDate(2020, 1, 1);
+        var quantity = new CqlQuantity(5, "year");
+        var result = date.Subtract(quantity);
+        Assert.AreEqual(new CqlDate(2015, 1, 1), result);
+    }
+
+    [TestMethod]
+    public void Subtract_Months()
+    {
+        var date = new CqlDate(2020, 3, 31);
+        var quantity = new CqlQuantity(1, "month");
+        var result = date.Subtract(quantity);
+        Assert.AreEqual(new CqlDate(2020, 2, 29), result); // Leap year
+    }
+
+    [TestMethod]
+    public void Subtract_Days()
+    {
+        var date = new CqlDate(2020, 3, 1);
+        var quantity = new CqlQuantity(1, "day");
+        var result = date.Subtract(quantity);
+        Assert.AreEqual(new CqlDate(2020, 2, 29), result);
+    }
+
+    [TestMethod]
+    public void Operator_Addition()
+    {
+        var date = new CqlDate(2021, 12, 31);
+        var quantity = new CqlQuantity(1, "day");
+        var result = date + quantity;
+        Assert.AreEqual(new CqlDate(2022, 1, 1), result);
+    }
+
+    [TestMethod]
+    public void Operator_Subtraction()
+    {
+        var date = new CqlDate(2022, 1, 1);
+        var quantity = new CqlQuantity(1, "day");
+        var result = date - quantity;
+        Assert.AreEqual(new CqlDate(2021, 12, 31), result);
+    }
+
+    [TestMethod]
+    public void Add_NullQuantity_ReturnsNull()
+    {
+        var date = new CqlDate(2020, 1, 1);
+        CqlQuantity? quantity = null;
+        var result = date.Add(quantity);
+        Assert.IsNull(result);
+    }
+
+    [TestMethod]
+    public void Subtract_NullQuantity_ReturnsNull()
+    {
+        var date = new CqlDate(2020, 1, 1);
+        CqlQuantity? quantity = null;
+        var result = date.Subtract(quantity);
+        Assert.IsNull(result);
+    }
+
+    [TestMethod]
+    public void Operator_Addition_NullDate_ReturnsNull()
+    {
+        CqlDate? date = null;
+        var quantity = new CqlQuantity(1, "day");
+        var result = date + quantity;
+        Assert.IsNull(result);
+    }
+
+    [TestMethod]
+    public void Operator_Subtraction_NullDate_ReturnsNull()
+    {
+        CqlDate? date = null;
+        var quantity = new CqlQuantity(1, "day");
+        var result = date - quantity;
+        Assert.IsNull(result);
+    }
+}