Provide dispose flag to opt-in to provider disposing logger; fixes #41.

Author: nblumhardt

src/Serilog.Extensions.Logging/Extensions/Logging/SerilogLoggerProvider.cs

@@ -21,11 +21,20 @@ class SerilogLoggerProvider : ILoggerProvider, ILogEventEnricher
 
         // May be null; if it is, Log.Logger will be lazily used
         readonly ILogger _logger;
+        readonly Action _dispose;
 
-        public SerilogLoggerProvider(ILogger logger = null)
+        public SerilogLoggerProvider(ILogger logger = null, bool dispose = false)
         {
             if (logger != null)
                 _logger = logger.ForContext(new[] { this });
+
+            if (dispose)
+            {
+                if (logger != null)
+                    _dispose = () => (logger as IDisposable)?.Dispose();
+                else
+                    _dispose = Log.CloseAndFlush;
+            }
         }
 
         public FrameworkLogger CreateLogger(string name)
@@ -77,6 +86,9 @@ public SerilogLoggerScope CurrentScope
         }
 #endif
 
-        public void Dispose() { }
+        public void Dispose()
+        {
+            _dispose?.Invoke();
+        }
     }
 }

src/Serilog.Extensions.Logging/SerilogLoggerFactoryExtensions.cs

@@ -17,14 +17,18 @@ public static class SerilogLoggerFactoryExtensions
         /// </summary>
         /// <param name="factory">The logger factory to configure.</param>
         /// <param name="logger">The Serilog logger; if not supplied, the static <see cref="Serilog.Log"/> will be used.</param>
+        /// <param name="dispose">When true, dispose <paramref name="logger"/> when the framework disposes the provider. If the
+        /// logger is not specified but <paramref name="dispose"/> is true, the <see cref="Log.CloseAndFlush()"/> method will be
+        /// called on the static <see cref="Log"/> class instead.</param>
         /// <returns>The logger factory.</returns>
         public static ILoggerFactory AddSerilog(
             this ILoggerFactory factory,
-            ILogger logger = null)
+            ILogger logger = null,
+            bool dispose = false)
         {
             if (factory == null) throw new ArgumentNullException(nameof(factory));
 
-            factory.AddProvider(new SerilogLoggerProvider(logger));
+            factory.AddProvider(new SerilogLoggerProvider(logger, dispose));
 
             return factory;
         }

test/Serilog.Extensions.Logging.Tests/SerilogLoggerTests.cs

@@ -9,6 +9,7 @@
 using System.IO;
 using System.Linq;
 using Serilog.Debugging;
+using Serilog.Framework.Logging.Tests.Support;
 using Xunit;
 
 namespace Serilog.Extensions.Logging.Test
@@ -269,6 +270,24 @@ public void CarriesEventIdIfNonzero()
             Assert.Equal(42, id.Value);
         }
 
+        [Fact]
+        public void WhenDisposeIsFalseProvidedLoggerIsNotDisposed()
+        {
+            var logger = new DisposeTrackingLogger();
+            var provider = new SerilogLoggerProvider(logger, false);
+            provider.Dispose();
+            Assert.False(logger.IsDisposed);
+        }
+
+        [Fact]
+        public void WhenDisposeIsTrueProvidedLoggerIsDisposed()
+        {
+            var logger = new DisposeTrackingLogger();
+            var provider = new SerilogLoggerProvider(logger, true);
+            provider.Dispose();
+            Assert.True(logger.IsDisposed);
+        }
+
         private class FoodScope : IEnumerable<KeyValuePair<string, object>>
         {
             readonly string _name;