Merge pull request #1588 from nunit/Loggers

Ensure Loggers use late bound `TraceLevel` and `Writer`.

src/NUnitEngine/nunit.engine.core.tests/Internal/Logging/LoggingTests.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Charlie Poole, Rob Prouse and Contributors. MIT License - see LICENSE.txt
 
 using System.IO;
-using NUnit.Engine.Internal;
 using NUnit.Framework;
 
 namespace NUnit.Engine.Internal.Logging
@@ -16,7 +15,7 @@ public void LoggerSelectsMessagesToWrite(
             [ValueSource(nameof(LEVELS))] InternalTraceLevel msgLevel)
         {
             var writer = new StringWriter();
-            var logger = new Logger("MyLogger", logLevel, writer);
+            var logger = new Logger("MyLogger", () => logLevel, () => writer);
 
             Assert.That(logger.TraceLevel, Is.EqualTo(logLevel));
 

src/NUnitEngine/nunit.engine.core/Internal/Logging/InternalTrace.cs

@@ -42,15 +42,12 @@ public static void Initialize(string logName, InternalTraceLevel level)
             {
                 DefaultTraceLevel = level;
 
-                if (_traceWriter == null)
-                {
-                    // We create the trace writer even if tracing is off, because
-                    // individual loggers are able to override the default level.
-                    _traceWriter = new InternalTraceWriter(logName);
+                // We create the trace writer even if tracing is off, because
+                // individual loggers are able to override the default level.
+                _traceWriter = new InternalTraceWriter(logName);
 
-                    if (DefaultTraceLevel > InternalTraceLevel.Off)
-                        _traceWriter.WriteLine("InternalTrace: Initializing at level {0}", DefaultTraceLevel);
-                }
+                if (DefaultTraceLevel > InternalTraceLevel.Off)
+                    _traceWriter.WriteLine("InternalTrace: Initializing at level {0}", DefaultTraceLevel);
 
                 Initialized = true;
             }
@@ -63,7 +60,7 @@ public static void Initialize(string logName, InternalTraceLevel level)
         /// </summary>
         public static Logger GetLogger(string name, InternalTraceLevel level)
         {
-            return new Logger(name, level, _traceWriter);
+            return new Logger(name, () => level, () => _traceWriter);
         }
 
         /// <summary>
@@ -79,15 +76,15 @@ public static Logger GetLogger(Type type, InternalTraceLevel level)
         /// </summary>
         public static Logger GetLogger(string name)
         {
-            return new Logger(name, DefaultTraceLevel, _traceWriter);
+            return new Logger(name, () => DefaultTraceLevel, () => _traceWriter);
         }
 
         /// <summary>
         /// Get a logger named for a particular Type using the default TraceLevel.
         /// </summary>
         public static Logger GetLogger(Type type)
         {
-            return GetLogger(type.FullName, DefaultTraceLevel);
+            return GetLogger(type.FullName);
         }
     }
 }

src/NUnitEngine/nunit.engine.core/Internal/Logging/InternalTraceWriter.cs

@@ -1,5 +1,6 @@
 // Copyright (c) Charlie Poole, Rob Prouse and Contributors. MIT License - see LICENSE.txt
 using System.IO;
+using NUnit.Common;
 
 namespace NUnit.Engine.Internal
 {
@@ -30,6 +31,8 @@ internal InternalTraceWriter(string logPath)
         /// <param name="writer"></param>
         public InternalTraceWriter(TextWriter writer)
         {
+            Guard.ArgumentNotNull(writer, nameof(writer));
+
             _writer = writer;
         }
 
@@ -62,7 +65,7 @@ public override void Write(string value)
         {
             lock (_myLock)
             {
-                base.Write(value);
+                _writer.Write(value);
             }
         }
 
@@ -102,8 +105,7 @@ protected override void Dispose(bool disposing)
         /// </summary>
         public override void Flush()
         {
-            if ( _writer != null )
-                _writer.Flush();
+            _writer.Flush();
         }
     }
-}
+}

src/NUnitEngine/nunit.engine.core/Internal/Logging/Logger.cs

@@ -14,20 +14,21 @@ public class Logger : ILogger
         private const string TraceFmt = "{0} {1,-5} [{2,2}] {3}: {4}";
 
         private readonly string _name;
-        private readonly TextWriter _writer;
+        private readonly Func<TextWriter> _getWriterFn;
+        private readonly Func<InternalTraceLevel> _getLevelFn;
 
-        public InternalTraceLevel TraceLevel { get; }
+        public InternalTraceLevel TraceLevel => _getLevelFn.Invoke();
 
         /// <summary>
         /// Initializes a new instance of the <see cref="Logger"/> class.
         /// </summary>
         /// <param name="fullName">The name.</param>
-        /// <param name="level">The log level.</param>
-        /// <param name="writer">The writer where logs are sent.</param>
-        public Logger(string fullName, InternalTraceLevel level, TextWriter writer)
+        /// <param name="getLevelFn">The log level.</param>
+        /// <param name="getWriterFn">The writer where logs are sent.</param>
+        public Logger(string fullName, Func<InternalTraceLevel> getLevelFn, Func<TextWriter> getWriterFn)
         {
-            TraceLevel = level;
-            _writer = writer;
+            _getLevelFn = getLevelFn;
+            _getWriterFn = getWriterFn;
 
             var index = fullName.LastIndexOf('.');
             _name = index >= 0 ? fullName.Substring(index + 1) : fullName;
@@ -111,7 +112,7 @@ public void Debug(string format, params object[] args)
 
         private void Log(InternalTraceLevel level, string message)
         {
-            if (_writer != null && TraceLevel >= level)
+            if (TraceLevel >= level)
                 WriteLog(level, message);
         }
 
@@ -123,7 +124,7 @@ private void Log(InternalTraceLevel level, string format, params object[] args)
 
         private void WriteLog(InternalTraceLevel level, string message)
         {
-            _writer.WriteLine(TraceFmt,
+            _getWriterFn.Invoke().WriteLine(TraceFmt,
                 DateTime.Now.ToString(TimeFmt),
                 level,
 #if NET20