Merge pull request #293 from SamSmithNZ-dotcom/copilot/add-comments-to-skittle-tests

Add missing Arrange/Act/Assert comments and improve exception specificity in SkittleTests

Author: samsmithnz

src/MandMCounter.Core/Calculator.cs

@@ -85,7 +85,7 @@ private static float GetCubicCmForVolume(string unit, float quantity)
         {
             if (string.IsNullOrEmpty(unit))
             {
-                unit = "";
+                throw new ArgumentNullException(nameof(unit), "Unit cannot be null or empty.");
             }
 
             switch (unit.ToLower())

src/MandMCounter.Tests/SkittleTests.cs

@@ -109,7 +109,7 @@ public void CountSkittlesInANullUnitTest()
             float quantity = 1;
 
             //Act & Assert
-            Assert.Throws<Exception>(() => Calculator.CountSkittles(unit, quantity));
+            Assert.Throws<ArgumentNullException>(() => Calculator.CountSkittles(unit, quantity));
         }
 
         [TestMethod]
@@ -169,11 +169,15 @@ public void CountSkittlesInA1CubicInchTest()
         [TestMethod]
         public void CountSkittlesInA1CubicNullUnitTest()
         {
+            //Arrange
             string unit = null;
             float height = 1;
             float width = 1;
             float length = 1;
 
+            //Act
+
+            //Assert
             Assert.Throws<Exception>(() => Calculator.CountSkittles(unit, height, width, length));
         }
 
@@ -216,10 +220,12 @@ public void CountSkittlesInACylinderWithInchTest()
         [TestMethod]
         public void CountSkittlesInACylinderWithNullUnitTest()
         {
+            //Arrange
             string unit = null;
             float height = 10;
             float radius = 5;
 
+            //Act & Assert
             Assert.Throws<Exception>(() => Calculator.CountSkittles(unit, height, radius));
         }