feat: Adjust 5.10 to handle an empty middle initial (#800)

Author: BenjaminMichaelis

src/Chapter05.Tests/Listing05.10.StringBuilderImplicitUsingStatements.Tests.cs

@@ -5,7 +5,7 @@ namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter05.Listing05_10.Tests;
 public class ProgramTests
 {
     [TestMethod]
-    public void Main_InputInigoMontoya_WriteFullName()
+    public void Main_InputInigoTMontoya_WriteFullName()
     {
         string view = """
             Enter your first name: <<Inigo
@@ -20,4 +20,21 @@ Hello Inigo T. Montoya!
         IntelliTect.TestTools.Console.ConsoleAssert.Expect(view,
             Program.Main);
     }
+
+    [TestMethod]
+    public void Main_InputInigoMontoya_WriteFullName()
+    {
+        string view = """
+            Enter your first name: <<Inigo
+            >>
+            Enter your middle initial: <<
+            >>
+            Enter your last name: <<Montoya
+            >>
+            Hello Inigo Montoya!
+            """;
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(view,
+            Program.Main);
+    }
 }

src/Chapter05/Listing05.10.StringBuilderImplicitUsingStatements.cs

@@ -16,7 +16,11 @@ public static void Main()
         name.Append(Console.ReadLine()!.Trim());
 
         Console.WriteLine("Enter your middle initial: ");
-        name.Append( $" { Console.ReadLine()!.Trim('.').Trim() }." );
+        string middleInitial = Console.ReadLine()!.Trim('.').Trim();
+        if (middleInitial != "")
+        {
+            name.Append($" {middleInitial}.");
+        }
 
         Console.WriteLine("Enter your last name: ");
         name.Append($" { Console.ReadLine()!.Trim() }");