Merge pull request #142 from IntelliTect/UpdateChapter03Listings

Updated Listing 03.01

src/Chapter03.Tests/Listing03.01.Tests.cs

@@ -0,0 +1,30 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter03.Listing03_01.Tests
+{
+    [TestClass]
+    public class UppercaseTests
+    {
+        [TestMethod]
+        public void Main_GivenArgs_NumberDoubles()
+        {
+            string[] args = { "arg0", "arg1" };
+            string expected =
+                $"\'number\' doubled is { args[0].Length * 2 }.";
+
+            IntelliTect.TestTools.Console.ConsoleAssert.Expect(
+                expected, ()=>Program.Main(args));
+        }
+
+        [TestMethod]
+        public void Main_GivenValidString_MakeUppercase()
+        {
+            string[] args = { };
+            const string expected =
+                "\'number\' requires a value and cannot be null";
+
+            IntelliTect.TestTools.Console.ConsoleAssert.Expect(
+                expected, () => Program.Main(args));
+        }
+    }
+}

src/Chapter03/Listing03.01.CheckingForNull.cs

@@ -2,19 +2,25 @@ namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter03.Listing03_01
 {
     public class Program
     {
-        public static void Main()
+        public static void Main(string[] args)
         {
             int? number = null;
+
             // ...
+            if(args.Length>0)
+            {
+                number = args[0].Length;
+            }
+
             if (number is null)
             {
                 System.Console.WriteLine(
-                    $"{ nameof(number) } requires a value and cannot be null");
+                    "'number' requires a value and cannot be null");
             }
             else
             {
                 System.Console.WriteLine(
-                    $"{ nameof(number) } is of type { number.GetType() }.");
+                    $"'number' doubled is { number * 2 }.");
             }
 
         }