Add support C# 8 nullable reference types

appveyor.yml

@@ -1,6 +1,6 @@
 version: '{build}'
 skip_tags: true
-image: Visual Studio 2017
+image: Visual Studio 2019
 configuration: Release
 test: off
 build_script:

src/Serilog.Sinks.Console/ConsoleLoggerConfigurationExtensions.cs

@@ -54,12 +54,12 @@ public static LoggerConfiguration Console(
             this LoggerSinkConfiguration sinkConfiguration,
             LogEventLevel restrictedToMinimumLevel = LevelAlias.Minimum,
             string outputTemplate = DefaultConsoleOutputTemplate,
-            IFormatProvider formatProvider = null,
-            LoggingLevelSwitch levelSwitch = null,
+            IFormatProvider? formatProvider = null,
+            LoggingLevelSwitch? levelSwitch = null,
             LogEventLevel? standardErrorFromLevel = null,
-            ConsoleTheme theme = null, 
+            ConsoleTheme? theme = null, 
             bool applyThemeToRedirectedOutput = false,
-            object syncRoot = null)
+            object? syncRoot = null)
         {
             if (sinkConfiguration == null) throw new ArgumentNullException(nameof(sinkConfiguration));
             if (outputTemplate == null) throw new ArgumentNullException(nameof(outputTemplate));
@@ -68,7 +68,7 @@ public static LoggerConfiguration Console(
                 ConsoleTheme.None :
                 theme ?? SystemConsoleThemes.Literate;
 
-            syncRoot = syncRoot ?? DefaultSyncRoot;
+            syncRoot ??= DefaultSyncRoot;
 
             var formatter = new OutputTemplateRenderer(appliedTheme, outputTemplate, formatProvider);
             return sinkConfiguration.Sink(new ConsoleSink(appliedTheme, formatter, standardErrorFromLevel, syncRoot), restrictedToMinimumLevel, levelSwitch);
@@ -93,14 +93,15 @@ public static LoggerConfiguration Console(
             this LoggerSinkConfiguration sinkConfiguration,
             ITextFormatter formatter,
             LogEventLevel restrictedToMinimumLevel = LevelAlias.Minimum,
-            LoggingLevelSwitch levelSwitch = null,
+            LoggingLevelSwitch? levelSwitch = null,
             LogEventLevel? standardErrorFromLevel = null,
-            object syncRoot = null)
+            object? syncRoot = null)
         {
             if (sinkConfiguration == null) throw new ArgumentNullException(nameof(sinkConfiguration));
             if (formatter == null) throw new ArgumentNullException(nameof(formatter));
 
-            syncRoot = syncRoot ?? DefaultSyncRoot;
+            syncRoot ??= DefaultSyncRoot;
+
             return sinkConfiguration.Sink(new ConsoleSink(ConsoleTheme.None, formatter, standardErrorFromLevel, syncRoot), restrictedToMinimumLevel, levelSwitch);
         }
     }

src/Serilog.Sinks.Console/Serilog.Sinks.Console.csproj

@@ -4,7 +4,7 @@
     <Description>A Serilog sink that writes log events to the console/terminal.</Description>
     <VersionPrefix>4.0.0</VersionPrefix>
     <Authors>Serilog Contributors</Authors>
-    <TargetFrameworks>net45;netstandard1.3;netstandard2.0;netcoreapp1.1;netcoreapp2.0</TargetFrameworks>
+    <TargetFrameworks>net45;netstandard1.3;netstandard2.0;netstandard2.1;netcoreapp1.1;netcoreapp2.0;netcoreapp3.0;netcoreapp3.1;</TargetFrameworks>
     <AssemblyName>Serilog.Sinks.Console</AssemblyName>
     <AssemblyOriginatorKeyFile>../../assets/Serilog.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
@@ -20,17 +20,22 @@
     <GenerateAssemblyFileVersionAttribute>true</GenerateAssemblyFileVersionAttribute>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <!-- Don't reference the full NETStandard.Library -->
-    <DisableImplicitFrameworkReferences Condition=" '$(TargetFramework)' != 'netstandard2.0' And '$(TargetFramework)' != 'netcoreapp2.0' ">true</DisableImplicitFrameworkReferences>
+    <DisableImplicitFrameworkReferences Condition=" '$(TargetFramework)' != 'netstandard2.0' And '$(TargetFramework)' != 'netstandard2.1' And '$(TargetFramework)' != 'netcoreapp2.0' And '$(TargetFramework)' != 'netcoreapp3.0' And '$(TargetFramework)' != 'netcoreapp3.1' ">true</DisableImplicitFrameworkReferences>
     <TreatWarningsAsErrors>True</TreatWarningsAsErrors>
     <TreatSpecificWarningsAsErrors />
     <RootNamespace>Serilog</RootNamespace>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <LangVersion>8.0</LangVersion>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net45' ">
     <DefineConstants>$(DefineConstants);PINVOKE</DefineConstants>
   </PropertyGroup>
-
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.1' ">
+  
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.1' or '$(TargetFramework)' == 'netcoreapp2.0' or '$(TargetFramework)' == 'netcoreapp3.0' ">
     <DefineConstants>$(DefineConstants);PINVOKE;RUNTIME_INFORMATION</DefineConstants>
   </PropertyGroup>
 
@@ -44,15 +49,14 @@
     <Reference Include="Microsoft.CSharp" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' ">
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' or '$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netstandard2.1' ">
     <PackageReference Include="System.Console" Version="4.3.0" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.1' ">
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.1' or '$(TargetFramework)' == 'netcoreapp2.0' or '$(TargetFramework)' == 'netcoreapp3.0' or '$(TargetFramework)' == 'netcoreapp3.1' ">
     <PackageReference Include="System.Console" Version="4.3.0" />
     <PackageReference Include="System.Runtime.InteropServices" Version="4.3.0" />
     <PackageReference Include="System.Runtime.InteropServices.RuntimeInformation" Version="4.3.0" />
   </ItemGroup>
-
 
-</Project>
+</Project>

src/Serilog.Sinks.Console/Sinks/SystemConsole/Formatting/ThemedDisplayValueFormatter.cs

@@ -22,9 +22,9 @@ namespace Serilog.Sinks.SystemConsole.Formatting
 {
     class ThemedDisplayValueFormatter : ThemedValueFormatter
     {
-        readonly IFormatProvider _formatProvider;
+        readonly IFormatProvider? _formatProvider;
 
-        public ThemedDisplayValueFormatter(ConsoleTheme theme, IFormatProvider formatProvider)
+        public ThemedDisplayValueFormatter(ConsoleTheme theme, IFormatProvider? formatProvider)
             : base(theme)
         {
             _formatProvider = formatProvider;
@@ -150,7 +150,7 @@ protected override int VisitDictionaryValue(ThemedValueFormatterState state, Dic
             return count;
         }
 
-        public int FormatLiteralValue(ScalarValue scalar, TextWriter output, string format)
+        public int FormatLiteralValue(ScalarValue scalar, TextWriter output, string? format)
         {
             var value = scalar.Value;
             var count = 0;

src/Serilog.Sinks.Console/Sinks/SystemConsole/Formatting/ThemedJsonValueFormatter.cs

@@ -24,9 +24,9 @@ namespace Serilog.Sinks.SystemConsole.Formatting
     class ThemedJsonValueFormatter : ThemedValueFormatter
     {
         readonly ThemedDisplayValueFormatter _displayFormatter;
-        readonly IFormatProvider _formatProvider;
+        readonly IFormatProvider? _formatProvider;
 
-        public ThemedJsonValueFormatter(ConsoleTheme theme, IFormatProvider formatProvider)
+        public ThemedJsonValueFormatter(ConsoleTheme theme, IFormatProvider? formatProvider)
             : base(theme)
         {
             _displayFormatter = new ThemedDisplayValueFormatter(theme, formatProvider);
@@ -154,7 +154,7 @@ protected override int VisitDictionaryValue(ThemedValueFormatterState state, Dic
                         : ConsoleThemeStyle.Scalar;
 
                 using (ApplyStyle(state.Output, style, ref count))
-                    JsonValueFormatter.WriteQuotedJsonString((element.Key.Value ?? "null").ToString(), state.Output);
+                    JsonValueFormatter.WriteQuotedJsonString((element.Key.Value?.ToString() ?? "null"), state.Output);
 
                 using (ApplyStyle(state.Output, ConsoleThemeStyle.TertiaryText, ref count))
                     state.Output.Write(": ");
@@ -248,7 +248,7 @@ int FormatLiteralValue(ScalarValue scalar, TextWriter output)
             }
 
             using (ApplyStyle(output, ConsoleThemeStyle.Scalar, ref count))
-                JsonValueFormatter.WriteQuotedJsonString(value.ToString(), output);
+                JsonValueFormatter.WriteQuotedJsonString(value.ToString() ?? "null", output);
 
             return count;
         }

src/Serilog.Sinks.Console/Sinks/SystemConsole/Formatting/ThemedValueFormatter.cs

@@ -34,7 +34,7 @@ protected StyleReset ApplyStyle(TextWriter output, ConsoleThemeStyle style, ref
             return _theme.Apply(output, style, ref invisibleCharacterCount);
         }
 
-        public int Format(LogEventPropertyValue value, TextWriter output, string format, bool literalTopLevel = false)
+        public int Format(LogEventPropertyValue value, TextWriter output, string? format, bool literalTopLevel = false)
         {
             return Visit(new ThemedValueFormatterState { Output = output, Format = format, IsTopLevel = literalTopLevel }, value);
         }

src/Serilog.Sinks.Console/Sinks/SystemConsole/Formatting/ThemedValueFormatterState.cs

@@ -19,7 +19,7 @@ namespace Serilog.Sinks.SystemConsole.Formatting
     struct ThemedValueFormatterState
     {
         public TextWriter Output;
-        public string Format;
+        public string? Format;
         public bool IsTopLevel;
 
         public ThemedValueFormatterState Nest() => new ThemedValueFormatterState { Output = Output };

src/Serilog.Sinks.Console/Sinks/SystemConsole/Output/EventPropertyTokenRenderer.cs

@@ -25,9 +25,9 @@ class EventPropertyTokenRenderer : OutputTemplateTokenRenderer
     {
         readonly ConsoleTheme _theme;
         readonly PropertyToken _token;
-        readonly IFormatProvider _formatProvider;
+        readonly IFormatProvider? _formatProvider;
 
-        public EventPropertyTokenRenderer(ConsoleTheme theme, PropertyToken token, IFormatProvider formatProvider)
+        public EventPropertyTokenRenderer(ConsoleTheme theme, PropertyToken token, IFormatProvider? formatProvider)
         {
             _theme = theme;
             _token = token;
@@ -62,7 +62,7 @@ public override void Render(LogEvent logEvent, TextWriter output)
 
                 if (_token.Alignment.HasValue)
                 {
-                    var str = writer.ToString();
+                    var str = writer.ToString() ?? throw new InvalidOperationException("The output TextWriter, return a invalid state.");
                     Padding.Apply(output, str, _token.Alignment);
                 }
             }

src/Serilog.Sinks.Console/Sinks/SystemConsole/Output/ExceptionTokenRenderer.cs

@@ -38,7 +38,7 @@ public override void Render(LogEvent logEvent, TextWriter output)
                 return;
 
             var lines = new StringReader(logEvent.Exception.ToString());
-            string nextLine;
+            string? nextLine;
             while ((nextLine = lines.ReadLine()) != null)
             {
                 var style = nextLine.StartsWith(StackFrameLinePrefix) ? ConsoleThemeStyle.SecondaryText : ConsoleThemeStyle.Text;

src/Serilog.Sinks.Console/Sinks/SystemConsole/Output/LevelOutputFormat.cs

@@ -55,7 +55,7 @@ static class LevelOutputFormat
             new[] { "F", "FA", "FTL", "FATL" },
         };
 
-        public static string GetLevelMoniker(LogEventLevel value, string format = null)
+        public static string GetLevelMoniker(LogEventLevel value, string? format = null)
         {
             if (format == null || format.Length != 2 && format.Length != 3)
                 return Casing.Format(value.ToString(), format);

src/Serilog.Sinks.Console/Sinks/SystemConsole/Output/LevelTokenRenderer.cs

@@ -42,10 +42,6 @@ public LevelTokenRenderer(ConsoleTheme theme, PropertyToken levelToken)
             _levelToken = levelToken;
         }
 
-        protected LevelTokenRenderer()
-        {
-        }
-
         public override void Render(LogEvent logEvent, TextWriter output)
         {
             var moniker = LevelOutputFormat.GetLevelMoniker(logEvent.Level, _levelToken.Format);

src/Serilog.Sinks.Console/Sinks/SystemConsole/Output/MessageTemplateOutputTokenRenderer.cs

@@ -28,10 +28,11 @@ class MessageTemplateOutputTokenRenderer : OutputTemplateTokenRenderer
         readonly PropertyToken _token;
         readonly ThemedMessageTemplateRenderer _renderer;
 
-        public MessageTemplateOutputTokenRenderer(ConsoleTheme theme, PropertyToken token, IFormatProvider formatProvider)
+        public MessageTemplateOutputTokenRenderer(ConsoleTheme theme, PropertyToken token, IFormatProvider? formatProvider)
         {
             _theme = theme ?? throw new ArgumentNullException(nameof(theme));
             _token = token ?? throw new ArgumentNullException(nameof(token));
+
             bool isLiteral = false, isJson = false;
 
             if (token.Format != null)

src/Serilog.Sinks.Console/Sinks/SystemConsole/Output/OutputTemplateRenderer.cs

@@ -27,9 +27,10 @@ class OutputTemplateRenderer : ITextFormatter
     {
         readonly OutputTemplateTokenRenderer[] _renderers;
 
-        public OutputTemplateRenderer(ConsoleTheme theme, string outputTemplate, IFormatProvider formatProvider)
+        public OutputTemplateRenderer(ConsoleTheme theme, string outputTemplate, IFormatProvider? formatProvider)
         {
             if (outputTemplate == null) throw new ArgumentNullException(nameof(outputTemplate));
+
             var template = new MessageTemplateParser().Parse(outputTemplate);
 
             var renderers = new List<OutputTemplateTokenRenderer>();

src/Serilog.Sinks.Console/Sinks/SystemConsole/Output/PropertiesTokenRenderer.cs

@@ -31,11 +31,12 @@ class PropertiesTokenRenderer : OutputTemplateTokenRenderer
         readonly PropertyToken _token;
         readonly ThemedValueFormatter _valueFormatter;
 
-        public PropertiesTokenRenderer(ConsoleTheme theme, PropertyToken token, MessageTemplate outputTemplate, IFormatProvider formatProvider)
+        public PropertiesTokenRenderer(ConsoleTheme theme, PropertyToken token, MessageTemplate outputTemplate, IFormatProvider? formatProvider)
         {
             _outputTemplate = outputTemplate;
             _theme = theme ?? throw new ArgumentNullException(nameof(theme));
             _token = token ?? throw new ArgumentNullException(nameof(token));
+
             var isJson = false;
 
             if (token.Format != null)

src/Serilog.Sinks.Console/Sinks/SystemConsole/Output/TimestampTokenRenderer.cs

@@ -25,9 +25,9 @@ class TimestampTokenRenderer : OutputTemplateTokenRenderer
     {
         readonly ConsoleTheme _theme;
         readonly PropertyToken _token;
-        readonly IFormatProvider _formatProvider;
+        readonly IFormatProvider? _formatProvider;
 
-        public TimestampTokenRenderer(ConsoleTheme theme, PropertyToken token, IFormatProvider formatProvider)
+        public TimestampTokenRenderer(ConsoleTheme theme, PropertyToken token, IFormatProvider? formatProvider)
         {
             _theme = theme;
             _token = token;

src/Serilog.Sinks.Console/Sinks/SystemConsole/Rendering/Casing.cs

@@ -23,7 +23,7 @@ static class Casing
         /// <param name="value">Provided string for formatting.</param>
         /// <param name="format">Format string.</param>
         /// <returns>The provided <paramref name="value"/> with formatting applied.</returns>
-        public static string Format(string value, string format = null)
+        public static string Format(string value, string? format = null)
         {
             switch (format)
             {

src/Serilog.Sinks.Console/Sinks/SystemConsole/Rendering/ThemedMessageTemplateRenderer.cs

@@ -102,11 +102,12 @@ int RenderPropertyToken(PropertyToken pt, IReadOnlyDictionary<string, LogEventPr
 
         int RenderAlignedPropertyTokenUnbuffered(PropertyToken pt, TextWriter output, LogEventPropertyValue propertyValue)
         {
+            if(pt.Alignment == null) throw new ArgumentException("Invalid PropertyToken State. The PropertyToken should have a Alignment.", nameof(pt));
+
             var valueOutput = new StringWriter();
             RenderValue(NoTheme, _unthemedValueFormatter, propertyValue, valueOutput, pt.Format);
 
             var valueLength = valueOutput.ToString().Length;
-            // ReSharper disable once PossibleInvalidOperationException
             if (valueLength >= pt.Alignment.Value.Width)
             {
                 return RenderValue(_theme, _valueFormatter, propertyValue, output, pt.Format);
@@ -123,7 +124,7 @@ int RenderAlignedPropertyTokenUnbuffered(PropertyToken pt, TextWriter output, Lo
             return RenderValue(_theme, _valueFormatter, propertyValue, output, pt.Format);
         }
 
-        int RenderValue(ConsoleTheme theme, ThemedValueFormatter valueFormatter, LogEventPropertyValue propertyValue, TextWriter output, string format)
+        int RenderValue(ConsoleTheme theme, ThemedValueFormatter valueFormatter, LogEventPropertyValue propertyValue, TextWriter output, string? format)
         {
             if (_isLiteral && propertyValue is ScalarValue sv && sv.Value is string)
             {