Make the level mapping routines public

Author: nblumhardt

src/Serilog.Extensions.Logging/Extensions/Logging/LevelMapping.cs renamed to src/Serilog.Extensions.Logging/Extensions/Logging/LevelConvert.cs

@@ -15,14 +15,28 @@
 using Microsoft.Extensions.Logging;
 using Serilog.Events;
 
+// ReSharper disable RedundantCaseLabel
+
 namespace Serilog.Extensions.Logging
 {
-    static class LevelMapping
+    /// <summary>
+    /// Converts between Serilog and Microsoft.Extensions.Logging level enum values.
+    /// </summary>
+    public static class LevelConvert
     {
+        /// <summary>
+        /// Convert <paramref name="logLevel"/> to the equivalent Serilog <see cref="LogEventLevel"/>.
+        /// </summary>
+        /// <param name="logLevel">A Microsoft.Extensions.Logging <see cref="LogLevel"/>.</param>
+        /// <returns>The Serilog equivalent of <paramref name="logLevel"/>.</returns>
+        /// <remarks>The <see cref="LogLevel.None"/> value has no Serilog equivalent. It is mapped to
+        /// <see cref="LogEventLevel.Fatal"/> as the closest approximation, but this has entirely
+        /// different semantics.</remarks>
         public static LogEventLevel ToSerilogLevel(LogLevel logLevel)
         {
             switch (logLevel)
             {
+                case LogLevel.None:
                 case LogLevel.Critical:
                     return LogEventLevel.Fatal;
                 case LogLevel.Error:
@@ -33,13 +47,17 @@ public static LogEventLevel ToSerilogLevel(LogLevel logLevel)
                     return LogEventLevel.Information;
                 case LogLevel.Debug:
                     return LogEventLevel.Debug;
-                // ReSharper disable once RedundantCaseLabel
                 case LogLevel.Trace:
                 default:
                     return LogEventLevel.Verbose;
             }
         }
 
+        /// <summary>
+        /// Convert <paramref name="logEventLevel"/> to the equivalent Microsoft.Extensions.Logging <see cref="LogLevel"/>.
+        /// </summary>
+        /// <param name="logEventLevel">A Serilog <see cref="LogEventLevel"/>.</param>
+        /// <returns>The Microsoft.Extensions.Logging equivalent of <paramref name="logEventLevel"/>.</returns>
         public static LogLevel ToExtensionsLevel(LogEventLevel logEventLevel)
         {
             switch (logEventLevel)
@@ -54,7 +72,6 @@ public static LogLevel ToExtensionsLevel(LogEventLevel logEventLevel)
                     return LogLevel.Information;
                 case LogEventLevel.Debug:
                     return LogLevel.Debug;
-                // ReSharper disable once RedundantCaseLabel
                 case LogEventLevel.Verbose:
                 default:
                     return LogLevel.Trace;

src/Serilog.Extensions.Logging/Extensions/Logging/LoggerProviderCollectionSink.cs

@@ -38,7 +38,7 @@ sourceContextProperty is ScalarValue sourceContextValue &&
                 categoryName = sourceContext;
             }
 
-            var level = LevelMapping.ToExtensionsLevel(logEvent.Level);
+            var level = LevelConvert.ToExtensionsLevel(logEvent.Level);
             var slv = new SerilogLogValues(logEvent.MessageTemplate, logEvent.Properties);
 
             foreach (var provider in _providers.Providers)

src/Serilog.Extensions.Logging/Extensions/Logging/SerilogLogger.cs

@@ -39,7 +39,7 @@ public SerilogLogger(
 
         public bool IsEnabled(LogLevel logLevel)
         {
-            return _logger.IsEnabled(LevelMapping.ToSerilogLevel(logLevel));
+            return _logger.IsEnabled(LevelConvert.ToSerilogLevel(logLevel));
         }
 
         public IDisposable BeginScope<TState>(TState state)
@@ -49,7 +49,7 @@ public IDisposable BeginScope<TState>(TState state)
 
         public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
         {
-            var level = LevelMapping.ToSerilogLevel(logLevel);
+            var level = LevelConvert.ToSerilogLevel(logLevel);
             if (!_logger.IsEnabled(level))
             {
                 return;