- Addressed review comments:

  - Added XML docs throughout.
  - Improved unit test names.
  - Removed <RootNamespace> from project files.
- Removed unnecessary sample files from the Abstractions project.

Author: paulmedynski

src/Microsoft.Data.SqlClient.Extensions/Abstractions/doc/Sample.xml

@@ -23,7 +23,13 @@
   <!-- Build Config -->
   <PropertyGroup>
     <AssemblyName>Microsoft.Data.SqlClient.Extensions.Abstractions</AssemblyName>
-    <RootNamespace>$(AssemblyName)</RootNamespace>
+
+    <!--
+      Clear the root namespace since our directory structure doesn't match our
+      namespace definitions.  Otherwise, if omitted it would default to the
+      AssemblyName.
+    -->
+    <RootNamespace></RootNamespace>
 
     <!--
       We pin the AssemblyVersion of our package to the default major version

src/Microsoft.Data.SqlClient.Extensions/Abstractions/src/Abstractions.csproj

@@ -7,6 +7,11 @@ namespace Microsoft.Data.SqlClient;
 /// <include file='../doc/SqlAuthenticationProviderException.xml' path='docs/members[@name="SqlAuthenticationProviderException"]/SqlAuthenticationProviderException/*'/>
 public abstract class SqlAuthenticationProviderException : Exception
 {
+    /// <summary>
+    /// The string value used when the failure code is not known.
+    /// </summary>
+    private const string Unknown = "Unknown";
+    
     /// <include file='../doc/SqlAuthenticationProviderException.xml' path='docs/members[@name="SqlAuthenticationProviderException"]/ctor1/*'/>
     protected SqlAuthenticationProviderException(
         string message,
@@ -54,6 +59,4 @@ public override string ToString()
             $" Method={Method} FailureCode={FailureCode}" +
             $" ShouldRetry={ShouldRetry} RetryPeriod={RetryPeriod}";
     }
-
-    private const string Unknown = "Unknown";
 }

src/Microsoft.Data.SqlClient.Extensions/Abstractions/src/Sample.cs

@@ -9,16 +9,26 @@ namespace Microsoft.Data.SqlClient;
 /// <include file='../doc/SqlAuthenticationProvider.xml' path='docs/members[@name="SqlAuthenticationProvider"]/SqlAuthenticationProvider/*'/>
 public abstract partial class SqlAuthenticationProvider
 {
-    // This class implements the static GetProvider and SetProvider methods by
-    // using reflection to call into the Microsoft.Data.SqlClient package's
-    // SqlAuthenticationProviderManager class, if that assembly is present.
+    /// <summary>
+    /// This class implements the static GetProvider and SetProvider methods by
+    /// using reflection to call into the Microsoft.Data.SqlClient package's
+    /// SqlAuthenticationProviderManager class, if that assembly is present.
+    /// </summary>
     private static class Internal
     {
-        // Handles to the reflected get/set methods.
+        /// <summary>
+        /// Our handle to the reflected GetProvider() method.
+        /// </summary>
         private static MethodInfo? _getProvider = null;
+
+        /// <summary>
+        /// Our handle to the reflected SetProvider() method.
+        /// </summary>
         private static MethodInfo? _setProvider = null;
 
-        // Static construction performs the reflection lookups.
+        /// <summary>
+        /// Static construction performs the reflection lookups.
+        /// </summary>
         static Internal()
         {
             // If the MDS package is present, load its
@@ -86,6 +96,7 @@ ex is BadImageFormatException ||
                   ex is FileLoadException ||
                   ex is FileNotFoundException)
             {
+                // TODO: Logging
                 // SqlClientEventSource.Log.TryTraceEvent(
                 //     nameof(SqlAuthenticationProviderManager) +
                 //     $": Azure extension assembly={assemblyName} not found or " +
@@ -95,12 +106,17 @@ ex is FileLoadException ||
             // Any other exceptions are fatal.
         }
 
-        // Call the reflected GetProvider method.
-        //
-        // Returns null if reflection failed or any exceptions occur.
-        // Otherwise, returns as the reflected method does.
-        //
-        public static SqlAuthenticationProvider? GetProvider(
+        /// <summary>
+        /// Call the reflected GetProvider method.
+        /// </summary>
+        /// <param name="authenticationMethod">
+        ///   The authentication method whose provider to get.
+        /// </param>
+        /// <returns>
+        ///   Returns null if reflection failed or any exceptions occur.
+        ///   Otherwise, returns as the reflected method does.
+        /// </returns>
+        internal static SqlAuthenticationProvider? GetProvider(
             SqlAuthenticationMethod authenticationMethod)
         {
             if (_getProvider is null)
@@ -124,13 +140,21 @@ ex is NotSupportedException ||
             }
         }
 
-
-        // Call the reflected SetProvider method.
-        //
-        // Returns false if reflection failed, invocation fails, or any
-        // exceptions occur.  Otherwise, returns as the reflected method does.
-        //
-        public static bool SetProvider(
+        /// <summary>
+        /// Call the reflected SetProvider method.
+        /// </summary>
+        /// <param name="authenticationMethod">
+        ///   The authentication method whose provider to set.
+        /// </param>
+        /// <param name="provider">
+        ///   The provider to set.
+        /// </param>
+        /// <returns>
+        ///   Returns false if reflection failed, invocation fails, or any
+        ///   exceptions occur.  Otherwise, returns as the reflected method
+        ///   does.
+        /// </returns>
+        internal static bool SetProvider(
             SqlAuthenticationMethod authenticationMethod,
             SqlAuthenticationProvider provider)
         {

src/Microsoft.Data.SqlClient.Extensions/Abstractions/src/SqlAuthenticationProviderException.cs

@@ -27,8 +27,15 @@ public SqlAuthenticationToken(
         ExpiresOn = expiresOn;
     }
 
+    /// <summary>
+    /// The exception thrown by the SqlAuthenticationToken constructor.
+    /// </summary>
     internal sealed class TokenException : SqlAuthenticationProviderException
     {
+        /// <summary>
+        /// Construct with the exception message.
+        /// </summary>
+        /// <param name="message">The exception message.</param>
         internal TokenException(string message)
         : base(message)
         {

src/Microsoft.Data.SqlClient.Extensions/Abstractions/src/SqlAuthenticationProviderInternal.cs

@@ -6,9 +6,13 @@ namespace Microsoft.Data.SqlClient.Extensions.Abstractions.Test;
 
 public class SqlAuthenticationMethodTest
 {
-    // Verify the number of expected enum members.
+    #region Tests
+
+    /// <summary>
+    /// Verify the number of expected enum members.
+    /// </summary>
     [Fact]
-    public void Member_Count()
+    public void Confirm_Expected_Member_Count()
     {
 #if NET
         Assert.Equal(11, Enum.GetNames<SqlAuthenticationMethod>().Length);
@@ -17,9 +21,11 @@ public void Member_Count()
 #endif
     }
 
-    // Verify each of the enum member numeric values.
+    /// <summary>
+    /// Verify each of the enum member numeric values.
+    /// </summary>
     [Fact]
-    public void Member_Values()
+    public void Confirm_Expected_Member_Values()
     {
         Assert.Equal(0, (int)SqlAuthenticationMethod.NotSpecified);
         Assert.Equal(1, (int)SqlAuthenticationMethod.SqlPassword);
@@ -35,4 +41,6 @@ public void Member_Values()
         Assert.Equal(9, (int)SqlAuthenticationMethod.ActiveDirectoryDefault);
         Assert.Equal(10, (int)SqlAuthenticationMethod.ActiveDirectoryWorkloadIdentity);
     }
+
+    #endregion
 }

src/Microsoft.Data.SqlClient.Extensions/Abstractions/src/SqlAuthenticationToken.cs

@@ -6,10 +6,14 @@ namespace Microsoft.Data.SqlClient.Extensions.Abstractions.Test;
 
 public class SqlAuthenticationParametersTest
 {
-    // Verify that the properties are set correctly when nullable arguments are
-    // null.
+    #region Tests
+
+    /// <summary>
+    /// Verify that the properties are set correctly when nullable arguments are
+    /// null.
+    /// </summary>
     [Fact]
-    public void Constructor_WithNulls()
+    public void Constructor_ValidArguments_WithNulls()
     {
         var method = SqlAuthenticationMethod.ActiveDirectoryDeviceCodeFlow;
         var server = "server";
@@ -43,10 +47,12 @@ public void Constructor_WithNulls()
         Assert.Equal(timeout, parameters.ConnectionTimeout);
     }
 
-    // Verify that the properties are set correctly when nullable arguments
-    // are non-null.
+    /// <summary>
+    /// Verify that the properties are set correctly when nullable arguments are
+    /// non-null.
+    /// </summary>
     [Fact]
-    public void Constructor_WithoutNulls()
+    public void Constructor_ValidArguments_WithoutNulls()
     {
         var method = SqlAuthenticationMethod.ActiveDirectoryIntegrated;
         var server = "server";
@@ -79,4 +85,6 @@ public void Constructor_WithoutNulls()
         Assert.Equal(id, parameters.ConnectionId);
         Assert.Equal(timeout, parameters.ConnectionTimeout);
     }
+
+    #endregion
 }