Addressing comments from copilot

Author: benrr101

src/Microsoft.Data.SqlClient/tests/FunctionalTests/MultiplexerTests.cs

@@ -270,7 +270,7 @@ private static List<PacketData> MultiplexPacketList(bool isAsync, int dataSize,
                 if (stateObject._inBytesRead > 0)
                 {
                     // At least the header must be read
-                    Assert.True(stateObject._inBytesRead < TdsEnums.HEADER_LEN);
+                    Assert.False(stateObject._inBytesRead < TdsEnums.HEADER_LEN);
 
                     // The full packet must be read, too
                     Span<byte> header = stateObject._inBuff.AsSpan(0, TdsEnums.HEADER_LEN);

src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/ParameterTest/ParametersTest.cs

@@ -1021,7 +1021,7 @@ private static void RunParameterTest()
             object id2Value = cm.Parameters["@id2"].Value;
             if (id2Value is not null)
             {
-                // Null values are allowed, but must if it is not null, the expected guid must be set.
+                // Null values are allowed, but if it is not null, the expected guid must be set.
                 Assert.Equal(expectedGuid, (Guid)id2Value);
             }
         }

src/Microsoft.Data.SqlClient/tests/ManualTests/TracingTests/DiagnosticTest.cs

@@ -23,6 +23,7 @@
 using System.Runtime.CompilerServices;
 using System;
 using System.Data;
+using Microsoft.Data.SqlClient.Tests.Common;
 using Microsoft.DotNet.RemoteExecutor;
 
 namespace Microsoft.Data.SqlClient.ManualTesting.Tests
@@ -211,7 +212,10 @@ public void ExecuteXmlReaderTest()
 
                         conn.Open();
                         XmlReader reader = cmd.ExecuteXmlReader();
-                        reader.FlushResultSet();
+                        while (reader.Read())
+                        {
+                            // Flush results
+                        }
                     }
                 }, [WriteConnectionOpenBefore, WriteConnectionOpenAfter, WriteCommandBefore, WriteCommandAfter, WriteConnectionCloseBefore, WriteConnectionCloseAfter]);
                 return RemoteExecutor.SuccessExitCode;
@@ -420,7 +424,10 @@ public void ExecuteXmlReaderAsyncTest()
 
                         conn.Open();
                         XmlReader reader = await cmd.ExecuteXmlReaderAsync();
-                        reader.FlushResultSet();
+                        while (reader.Read())
+                        {
+                            // Flush results
+                        }
                     }
                 }, [WriteConnectionOpenBefore, WriteConnectionOpenAfter, WriteCommandBefore, WriteCommandAfter, WriteConnectionCloseBefore, WriteConnectionCloseAfter]).Wait();
                 return RemoteExecutor.SuccessExitCode;

src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft/Data/SqlClient/SqlErrorTests.cs

@@ -16,7 +16,7 @@ public void SerializationRoundTrip()
         {
             // Arrange
             DataContractSerializer serializer = new(typeof(SqlError));
-            MemoryStream stream = new();
+            using MemoryStream stream = new();
 
             // - Create the test error
             SqlError originalError = new(