Allow suppressing specific fields

Also default to omitting null values.  A configuration hook (CustomNullValue) can be used to preserve the legacy behavior

README.md

@@ -102,7 +102,7 @@ Multiple providers can be provied, for example, this application uses both `Cons
 ### Exception Entry
 
 > [2014-06-13 00:12:52.038Z] Application=MyApplication **Level=Error** Component=Program Operation=Main TimeElapsed=1027.0 Key=Value **ErrorReason="An exception has ocurred"** **Exception_Type=ApplicationException Exception_Message="you were unlucky!"** Exception_StackTrace="   at TestConsoleApp.Program.DoSomethingDangerous() in c:\src\git\github\chris-peterson\Spiffy\src\Tests\TestConsoleApp\Program.cs:line 47
-   at TestConsoleApp.Program.Main() in c:\src\git\github\chris-peterson\Spiffy\src\Tests\TestConsoleApp\Program.cs:line 29" InnermostException_Type=NullReferenceException **InnermostException_Message="Object reference not set to an instance of an object."** InnermostException_StackTrace={null} Exception="See Exception_* and InnermostException_* for more details" TimeElapsed_LongRunning=1000.0
+   at TestConsoleApp.Program.Main() in c:\src\git\github\chris-peterson\Spiffy\src\Tests\TestConsoleApp\Program.cs:line 29" InnermostException_Type=NullReferenceException **InnermostException_Message="Object reference not set to an instance of an object."** Exception="See Exception_* and InnermostException_* for more details" TimeElapsed_LongRunning=1000.0
 
 ## Hosting Frameworks
 

src/Spiffy.Monitoring/BackwardsCompatabilityShims.cs

@@ -30,7 +30,7 @@ public static void IncludeInformationalException(this EventContext target, Excep
     public static class EventContextExtensions
     {
         [Obsolete("This extension should be avoided, instead preferring IncludeStructure on EventContext")]
-        public static EventContext IncludeStructure(this EventContext eventContext, object structure, string keyPrefix = null, bool includeNullValues = true)
+        public static EventContext IncludeStructure(this EventContext eventContext, object structure, string keyPrefix = null, bool includeNullValues = false)
         {
             return eventContext.IncludeStructure(structure, keyPrefix, includeNullValues);
         }

src/Spiffy.Monitoring/Config/Configuration.cs

@@ -20,6 +20,7 @@ public static void Initialize(Action<InitializationApi> customize)
 
             _beforeLoggingActions = api.GetBeforeLoggingActions();
             _loggingActions = api.GetLoggingActions();
+            CustomNullValue = api.CustomNullValue;
             RemoveNewLines = api.RemoveNewlines;
             DeprioritizedValueLength = api.DeprioritizedValueLength;
         }
@@ -34,6 +35,7 @@ internal static Action<LogEvent> [] GetLoggingActions()
             return _loggingActions;
         }
 
+        internal static string CustomNullValue { get; set; }
         internal static bool RemoveNewLines { get; private set; }
 
         internal static int DeprioritizedValueLength { get; private set; } = 1024;

src/Spiffy.Monitoring/Config/InitializationApi.cs

@@ -48,7 +48,12 @@ public InitializationApi()
             Providers = new ProvidersApi(this);
             Callbacks = new CallbacksApi(this);
         }
-
+
+        /// <summary>
+        /// If set, this value is used for logging values that are null.
+        /// </summary>
+        public string CustomNullValue { get; set; }
+
         /// <summary>
         /// Whether or not to remove newline characters from logged values.
         /// </summary>

src/Spiffy.Monitoring/EventContext.cs

@@ -177,6 +177,14 @@ public void Suppress()
             IsSuppressed = true;
         }
 
+        public void SuppressFields(params string [] fields)
+        {
+            foreach (var field in fields)
+            {
+                _values.TryRemove(field, out _);
+            }
+        }
+
         // ReSharper disable once RedundantDefaultMemberInitializer
         volatile bool _disposed = false;
 
@@ -221,13 +229,17 @@ public void Initialize(string component, string operation)
 
         internal LogEvent Render()
         {
-            var kvps = _values
+            IEnumerable<KeyValuePair<string, (uint Order, object Value)>> values = _values;
+            if (Configuration.CustomNullValue == null)
+            {
+                values = values.Where(kvp => kvp.Value.Value != null);
+            }
+            var kvps = values
                 .OrderBy(x => x.Value.Order)
                 .ToDictionary(
                     kvp => kvp.Key,
                     kvp => GetValue(kvp.Value.Value));
 
-
             foreach (var kvp in GetCountValues())
             {
                 kvps.Add(kvp.Key, kvp.Value);
@@ -315,7 +327,7 @@ static string GetValue(object value)
         {
             if (value == null)
             {
-                return "{null}";
+                return Configuration.CustomNullValue;
             }
 
             var str = value.ToString();

src/Spiffy.Monitoring/EventContext_ObjectMethods.cs

@@ -5,15 +5,15 @@ namespace Spiffy.Monitoring
 {
     public partial class EventContext
     {
-        public EventContext IncludeStructure(object structure, string keyPrefix = null, bool includeNullValues = true)
+        public EventContext IncludeStructure(object structure, string keyPrefix = null, bool includeNullValues = false)
         {
             if (structure != null)
             {
                 foreach (var property in structure.GetType().GetTypeInfo().DeclaredProperties.Where(p => p.CanRead))
                 {
                     try
                     {
-                        var val = property.GetValue(structure, null);
+                        var val = property.GetValue(structure, null) ?? Configuration.CustomNullValue;
                         if (val == null && !includeNullValues)
                         {
                             continue;

src/Spiffy.Monitoring/Spiffy.Monitoring.csproj

@@ -13,7 +13,7 @@
     <PackageReadmeFile>README.md</PackageReadmeFile>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
-    <Version>6.2.6</Version>
+    <Version>6.3.0</Version>
     <RootNamespace>Spiffy.Monitoring</RootNamespace>
     <LangVersion>latest</LangVersion>
   </PropertyGroup>

tests/TestConsoleApp/Program.cs

@@ -30,10 +30,11 @@ static void Main(string[] args)
                         break;
                     case "console":
                         Configuration.Initialize(spiffy => {
+                            spiffy.CustomNullValue = "<null>";
                             spiffy.Callbacks.BeforeLogging(eventContext => {
                                 if (eventContext.Level == Level.Info)
                                 {
-                                    eventContext.Suppress();
+                                    //eventContext.Suppress();
                                 }
                             });
                             spiffy.Providers.Console();
@@ -120,9 +121,13 @@ static void Main(string[] args)
             // info:
             using (var context = new EventContext("Greetings", "Start"))
             {
-                context["Greeting"] = "Hello world!";
+                context["Greeting"] = "hi";
+                context["MyField"] = null;
+                context.SuppressFields("Greeting");
             }
-
+
+            //return;
+
             while (true)
             {
                 // warning:

tests/UnitTests/Publishing.cs

@@ -18,6 +18,15 @@ public void Events_are_published_on_disposal()
             Then(It_should_publish_the_log_message);
         }
 
+        [Scenario]
+        public void Suppressed_fields_are_not_emitted()
+        {
+            Given(A_publishing_context)
+            .And(EventContext_fields_are_suppressed);
+            When(Disposing_an_event_context);
+            Then(Some_fields_are_omitted);
+        }
+
         [Scenario]
         public void Suppressed_events_are_not_published()
         {
@@ -127,6 +136,13 @@ void A_publishing_context()
             _context =new PublishingTestContext();
         }
 
+        void EventContext_fields_are_suppressed()
+        {
+            var field = "Uninteresting";
+            _context.EventContext[field] = "some value";
+            _context.EventContext.SuppressFields(field);
+        }
+
         void EventContext_is_suppressed()
         {
             _context.EventContext.Suppress();
@@ -144,6 +160,12 @@ void It_should_publish_the_log_message()
             logEvent.MessageWithTime.Length.Should().BeInRange(10, 200);
         }
 
+        void Some_fields_are_omitted()
+        {
+            var logEvent = _context.LogEvents.Single();
+            logEvent.Message.Should().NotContain("Uninteresting");
+        }
+
         void It_should_not_publish_again()
         {
             _context.LogEvents.Count.Should().Be(1);