diff --git a/src/Chapter05.Tests/Listing05.31.Tests.cs b/src/Chapter05.Tests/Listing05.31.Tests.cs
index 81a2451d2..129042df3 100644
--- a/src/Chapter05.Tests/Listing05.31.Tests.cs
+++ b/src/Chapter05.Tests/Listing05.31.Tests.cs
@@ -5,4 +5,22 @@ namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter05.Listing05_31.Tests;
 [TestClass]
 public class ProgramTests
 {
+    [TestMethod]
+    public void Main_NoArgs_ExpectErrors()
+    {
+        string expected = "Value cannot be null. (Parameter \'httpsUrl\')";
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main();
+            }catch(Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
+
 }
diff --git a/src/Chapter05.Tests/Listing05.32.Tests.cs b/src/Chapter05.Tests/Listing05.32.Tests.cs
index 7d4d627b1..1e19b25d6 100644
--- a/src/Chapter05.Tests/Listing05.32.Tests.cs
+++ b/src/Chapter05.Tests/Listing05.32.Tests.cs
@@ -5,5 +5,22 @@ namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter05.Listing05_32.Tests;
 [TestClass]
 public class ProgramTests
 {
+    [TestMethod]
+    public void Main_NoArgs_ExpectErrors()
+    {
+        string expected = "Value cannot be null. (Parameter \'httpsUrl\')";
 
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main();
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
 }
diff --git a/src/Chapter05.Tests/Listing05.33.Tests.cs b/src/Chapter05.Tests/Listing05.33.Tests.cs
index 8f18bbcfb..b7262f444 100644
--- a/src/Chapter05.Tests/Listing05.33.Tests.cs
+++ b/src/Chapter05.Tests/Listing05.33.Tests.cs
@@ -5,5 +5,180 @@ namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter05.Listing05_33.Tests;
 [TestClass]
 public class ProgramTests
 {
+    [TestMethod]
+    public void Main_NoArgs_ExpectErrors()
+    {
+        string[] args = Array.Empty<string>();
+        string expected = """
+            ERROR:  You must specify the URL and the file name
+            Usage: Downloader.exe <URL> <TargetFileName>
+            """;
 
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            Program.Main(args);
+        });
+    }
+
+#if !NET7_0_OR_GREATER
+[TestMethod]
+    public void Main_NoArgs_ExpectFirstNullError()
+    {
+        string[] args = {null! , "Montoya"};
+        string expected = "Value cannot be null. (Parameter \'httpsUrl\')";
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main(args);
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
+
+    [TestMethod]
+    public void Main_FirstArg_ExpectSecondNullError()
+    {
+        string[] args = { "Inigo", null! };
+        string expected = "Value cannot be null. (Parameter \'fileName\')";
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main(args);
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
+
+    [TestMethod]
+    public void Main_InvalidSecondArg_ExpectWhitespaceError()
+    {
+        string[] args = { "Inigo", "  " };
+        string expected = "fileName cannot be empty or only whitespace";
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main(args);
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
+#else
+    [TestMethod]
+    public void Main_NoArgs_ExpectFirstNullError()
+    {
+        string[] args = { null!, "Montoya" };
+        string expected = "Object reference not set to an instance of an object.";
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main(args);
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
+
+    [TestMethod]
+    public void Main_FirstArg_ExpectSecondNullError()
+    {
+        string[] args = { "Inigo", null! };
+        string expected = "Value cannot be null. (Parameter \'fileName?.Trim()\')";
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main(args);
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
+
+    [TestMethod]
+    public void Main_InvalidSecondArg_ExpectWhitespaceError()
+    {
+        string[] args = { "Inigo", "  " };
+        string expected = "The value cannot be an empty string. (Parameter \'fileName?.Trim()\')";
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main(args);
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
+#endif
+
+    [TestMethod]
+    public void Main_InvalidSecondArg_ExpectHTTPError()
+    {
+        string[] args = { "Inigo", "Montoya" };
+        string expected = "URL must start with \'HTTPS\'.";
+
+        IntelliTect.TestTools.Console.ConsoleAssert.Expect(expected,
+        () =>
+        {
+            try
+            {
+                Program.Main(args);
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex.Message);
+            }
+        });
+    }
+
+    [TestMethod]
+    public void Main_IntelliTectIndexHtmlArgs_DownloadFile()
+    {
+        try
+        {
+            string fileName = "about";
+            string[] args = { "https://IntelliTect.com", fileName };
+            string expected = $"Downloaded '{args[1]}' from '{args[0]}'.";
+
+            int? result = null;
+            IntelliTect.TestTools.Console.ConsoleAssert.Expect(
+                expected, () => result = Program.Main(args));
+        }
+        catch (AggregateException exception) when (exception.InnerException is System.Net.Http.HttpRequestException)
+        {
+            Assert.Inconclusive("Unable to download the file.  Check your internet connection.");
+        }
+    }
 }