Readme and some basic tests

Author: nhart12

Diff for: README.md

@@ -249,6 +249,7 @@ Basic settings of the sink are configured using the properties in a `MSSqlServer
 * `EagerlyEmitFirstEvent`
 * `LevelSwitch`
 * `UseSqlBulkCopy`
+* `ConnectionConfiguration`
 
 ### TableName
 
@@ -299,6 +300,10 @@ A switch allowing the pass-through minimum level to be changed at runtime. If th
 A flag to use `SqlBulkCopy` instead of individual INSERT statements when writing log events.  The default is `true`.
 This setting is not used by the audit sink as it always uses INSERT statements to write events.
 
+### ConnectionConfiguration
+
+An optional action to customize the underlying SqlConnection object. Can be used to set properties such as `AccessTokenCallback`.
+
 ## ColumnOptions Object
 
 Features of the log table are defined by changing properties on a `ColumnOptions` object:

Diff for: test/Serilog.Sinks.MSSqlServer.Tests/Sinks/MSSqlServer/Dependencies/SinkDependenciesFactoryTests.cs

@@ -1,7 +1,10 @@
-using Serilog.Sinks.MSSqlServer.Dependencies;
+using Moq;
+using System;
+using Serilog.Sinks.MSSqlServer.Dependencies;
 using Serilog.Sinks.MSSqlServer.Platform;
 using Serilog.Sinks.MSSqlServer.Tests.TestUtils;
 using Xunit;
+using Microsoft.Data.SqlClient;
 
 namespace Serilog.Sinks.MSSqlServer.Tests.Dependencies
 {
@@ -68,5 +71,19 @@ public void DefaultsColumnOptionsIfNull()
             // Act (should not throw)
             SinkDependenciesFactory.Create(_connectionString, _sinkOptions, null, null, null);
         }
+
+        [Fact]
+        public void CreatesSinkDependenciesWithSqlConnectionConfiguration()
+        {
+            // Arrange
+            var mockConfigurationAction = new Mock<Action<SqlConnection>>();
+            var sinkOptions = new MSSqlServerSinkOptions { TableName = "LogEvents", ConnectionConfiguration = mockConfigurationAction.Object };
+
+            // Act
+            var result = SinkDependenciesFactory.Create(_connectionString, sinkOptions, null, _columnOptions, null);
+
+            // Assert
+            Assert.NotNull(result.SqlDatabaseCreator);
+        }
     }
 }

Diff for: test/Serilog.Sinks.MSSqlServer.Tests/Sinks/MSSqlServer/Platform/SqlConnectionFactoryTests.cs

@@ -1,4 +1,5 @@
 using System;
+using Microsoft.Data.SqlClient;
 using Moq;
 using Serilog.Sinks.MSSqlServer.Platform;
 using Serilog.Sinks.MSSqlServer.Platform.SqlClient;
@@ -38,5 +39,23 @@ public void CreateConnectionReturnsConnectionWrapper()
                 Assert.IsAssignableFrom<ISqlConnectionWrapper>(connection);
             }
         }
+
+
+        [Fact]
+        public void CreateConnectionCallsCustomConfigurationAction()
+        {
+            // Arrange
+            var mockAction = new Mock<Action<SqlConnection>>();
+            var sut = new SqlConnectionFactory(_sqlConnectionStringBuilderWrapperMock.Object, mockAction.Object);
+
+            // Act
+            using (var connection = sut.Create())
+            {
+                // Assert
+                Assert.NotNull(connection);
+                Assert.IsAssignableFrom<ISqlConnectionWrapper>(connection);
+                mockAction.Verify(m => m.Invoke(connection.SqlConnection), Times.Once);
+            }
+        }
     }
 }