format and formatProvider can be null

src/Serilog/Capturing/PropertyBinder.cs

@@ -51,15 +51,13 @@ public EventProperty[] ConstructProperties(MessageTemplate messageTemplate, obje
             }
 
             if (messageTemplate.PositionalProperties != null)
-                return ConstructPositionalProperties(messageTemplate, messageTemplateParameters);
+                return ConstructPositionalProperties(messageTemplate, messageTemplateParameters, messageTemplate.PositionalProperties);
 
             return ConstructNamedProperties(messageTemplate, messageTemplateParameters!);
         }
 
-        EventProperty[] ConstructPositionalProperties(MessageTemplate template, object?[] messageTemplateParameters)
+        EventProperty[] ConstructPositionalProperties(MessageTemplate template, object?[] messageTemplateParameters, PropertyToken[] positionalProperties)
         {
-            var positionalProperties = template.PositionalProperties;
-
             if (positionalProperties.Length != messageTemplateParameters.Length)
                 SelfLog.WriteLine("Positional property count does not match parameter count: {0}", template);
 
@@ -107,7 +105,7 @@ EventProperty[] ConstructNamedProperties(MessageTemplate template, object[] mess
             var result = new EventProperty[messageTemplateParameters.Length];
             for (var i = 0; i < matchedRun; ++i)
             {
-                var property = template.NamedProperties[i];
+                var property = namedProperties[i];
                 var value = messageTemplateParameters[i];
                 result[i] = ConstructProperty(property, value);
             }

src/Serilog/Events/DictionaryValue.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -49,7 +50,7 @@ public DictionaryValue(IEnumerable<KeyValuePair<ScalarValue, LogEventPropertyVal
         /// <param name="formatProvider">A format provider to apply to the value, or null to use the default.</param>
         /// <seealso cref="LogEventPropertyValue.ToString(string, IFormatProvider)"/>.
         /// <exception cref="ArgumentNullException">When <paramref name="output"/> is <code>null</code></exception>
-        public override void Render(TextWriter output, string format = null, IFormatProvider formatProvider = null)
+        public override void Render(TextWriter output, string? format = null, IFormatProvider? formatProvider = null)
         {
             if (output == null) throw new ArgumentNullException(nameof(output));
 

src/Serilog/Events/LogEvent.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -25,7 +26,7 @@ public class LogEvent
     {
         readonly Dictionary<string, LogEventPropertyValue> _properties;
 
-        LogEvent(DateTimeOffset timestamp, LogEventLevel level, Exception exception, MessageTemplate messageTemplate, Dictionary<string, LogEventPropertyValue> properties)
+        LogEvent(DateTimeOffset timestamp, LogEventLevel level, Exception? exception, MessageTemplate messageTemplate, Dictionary<string, LogEventPropertyValue> properties)
         {
             Timestamp = timestamp;
             Level = level;
@@ -44,7 +45,7 @@ public class LogEvent
         /// <param name="properties">Properties associated with the event, including those presented in <paramref name="messageTemplate"/>.</param>
         /// <exception cref="ArgumentNullException">When <paramref name="messageTemplate"/> is <code>null</code></exception>
         /// <exception cref="ArgumentNullException">When <paramref name="properties"/> is <code>null</code></exception>
-        public LogEvent(DateTimeOffset timestamp, LogEventLevel level, Exception exception, MessageTemplate messageTemplate, IEnumerable<LogEventProperty> properties)
+        public LogEvent(DateTimeOffset timestamp, LogEventLevel level, Exception? exception, MessageTemplate messageTemplate, IEnumerable<LogEventProperty> properties)
             : this(timestamp, level, exception, messageTemplate, new Dictionary<string, LogEventPropertyValue>())
         {
             if (properties == null) throw new ArgumentNullException(nameof(properties));
@@ -63,7 +64,7 @@ public LogEvent(DateTimeOffset timestamp, LogEventLevel level, Exception excepti
         /// <param name="properties">Properties associated with the event, including those presented in <paramref name="messageTemplate"/>.</param>
         /// <exception cref="ArgumentNullException">When <paramref name="messageTemplate"/> is <code>null</code></exception>
         /// <exception cref="ArgumentNullException">When <paramref name="properties"/> is <code>null</code></exception>
-        internal LogEvent(DateTimeOffset timestamp, LogEventLevel level, Exception exception, MessageTemplate messageTemplate, EventProperty[] properties)
+        internal LogEvent(DateTimeOffset timestamp, LogEventLevel level, Exception? exception, MessageTemplate messageTemplate, EventProperty[] properties)
             : this(timestamp, level, exception, messageTemplate, new Dictionary<string, LogEventPropertyValue>(properties?.Length ?? throw new ArgumentNullException(nameof(properties))))
         {
             for (var i = 0; i < properties.Length; ++i)
@@ -91,7 +92,7 @@ internal LogEvent(DateTimeOffset timestamp, LogEventLevel level, Exception excep
         /// </summary>
         /// <param name="output">The output.</param>
         /// <param name="formatProvider">Supplies culture-specific formatting information, or null.</param>
-        public void RenderMessage(TextWriter output, IFormatProvider formatProvider = null)
+        public void RenderMessage(TextWriter output, IFormatProvider? formatProvider = null)
         {
             MessageTemplate.Render(Properties, output, formatProvider);
         }
@@ -101,7 +102,7 @@ public void RenderMessage(TextWriter output, IFormatProvider formatProvider = nu
         /// with the event, and return the result.
         /// </summary>
         /// <param name="formatProvider">Supplies culture-specific formatting information, or null.</param>
-        public string RenderMessage(IFormatProvider formatProvider = null)
+        public string RenderMessage(IFormatProvider? formatProvider = null)
         {
             return MessageTemplate.Render(Properties, formatProvider);
         }
@@ -114,7 +115,7 @@ public string RenderMessage(IFormatProvider formatProvider = null)
         /// <summary>
         /// An exception associated with the event, or null.
         /// </summary>
-        public Exception Exception { get; }
+        public Exception? Exception { get; }
 
         /// <summary>
         /// Add a property to the event if not already present, otherwise, update its value.

src/Serilog/Events/LogEventPropertyValue.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.IO;
 
@@ -30,7 +31,7 @@ public abstract class LogEventPropertyValue : IFormattable
         /// <param name="format">A format string applied to the value, or null.</param>
         /// <param name="formatProvider">A format provider to apply to the value, or null to use the default.</param>
         /// <seealso cref="LogEventPropertyValue.ToString(string, IFormatProvider)"/>.
-        public abstract void Render(TextWriter output, string format = null, IFormatProvider formatProvider = null);
+        public abstract void Render(TextWriter output, string? format = null, IFormatProvider? formatProvider = null);
 
         /// <summary>
         /// Returns a string that represents the current object.
@@ -52,7 +53,7 @@ public abstract class LogEventPropertyValue : IFormattable
         /// <param name="formatProvider">The provider to use to format the value.-or- A null reference
         /// (Nothing in Visual Basic) to obtain the numeric format information from the current locale
         /// setting of the operating system. </param><filterpriority>2</filterpriority>
-        public string ToString(string format, IFormatProvider formatProvider)
+        public string ToString(string? format, IFormatProvider? formatProvider)
         {
             var output = new StringWriter();
             Render(output, format, formatProvider);

src/Serilog/Events/MessageTemplate.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -122,9 +123,9 @@ static TResult[] GetElementsOfTypeToArray<TResult>(MessageTemplateToken[] tokens
 
         internal MessageTemplateToken[] TokenArray => _tokens;
 
-        internal PropertyToken[] NamedProperties { get; }
+        internal PropertyToken[]? NamedProperties { get; }
 
-        internal PropertyToken[] PositionalProperties { get; }
+        internal PropertyToken[]? PositionalProperties { get; }
 
         /// <summary>
         /// Convert the message template into a textual message, given the
@@ -136,7 +137,7 @@ static TResult[] GetElementsOfTypeToArray<TResult>(MessageTemplateToken[] tokens
         /// properties are mismatched with the template, the template will be
         /// returned with incomplete substitution.</returns>
         /// <exception cref="ArgumentNullException">When <paramref name="properties"/> is <code>null</code></exception>
-        public string Render(IReadOnlyDictionary<string, LogEventPropertyValue> properties, IFormatProvider formatProvider = null)
+        public string Render(IReadOnlyDictionary<string, LogEventPropertyValue> properties, IFormatProvider? formatProvider = null)
         {
             var writer = new StringWriter(formatProvider);
             Render(properties, writer, formatProvider);
@@ -154,7 +155,7 @@ public string Render(IReadOnlyDictionary<string, LogEventPropertyValue> properti
         /// <param name="formatProvider">Supplies culture-specific formatting information, or null.</param>
         /// <exception cref="ArgumentNullException">When <paramref name="properties"/> is <code>null</code></exception>
         /// <exception cref="ArgumentNullException">When <paramref name="output"/> is <code>null</code></exception>
-        public void Render(IReadOnlyDictionary<string, LogEventPropertyValue> properties, TextWriter output, IFormatProvider formatProvider = null)
+        public void Render(IReadOnlyDictionary<string, LogEventPropertyValue> properties, TextWriter output, IFormatProvider? formatProvider = null)
         {
             if (properties == null) throw new ArgumentNullException(nameof(properties));
             if (output == null) throw new ArgumentNullException(nameof(output));

src/Serilog/Formatting/Display/Obsolete/LiteralStringValue.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.IO;
 using Serilog.Events;
@@ -31,12 +32,12 @@ public LiteralStringValue(string value)
             _value = value ?? throw new ArgumentNullException(nameof(value));
         }
 
-        public override void Render(TextWriter output, string format = null, IFormatProvider formatProvider = null)
+        public override void Render(TextWriter output, string? format = null, IFormatProvider? formatProvider = null)
         {
             output.Write(Casing.Format(_value, format));
         }
 
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             return obj is LiteralStringValue sv && Equals(_value, sv._value);
         }

src/Serilog/Formatting/Display/Obsolete/LogEventLevelValue.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.IO;
 
@@ -32,7 +33,7 @@ public LogEventLevelValue(LogEventLevel value)
         /// <summary>
         /// This method will apply only upper or lower case formatting, not fixed width
         /// </summary>
-        public override void Render(TextWriter output, string format = null, IFormatProvider formatProvider = null)
+        public override void Render(TextWriter output, string? format = null, IFormatProvider? formatProvider = null)
         {
             output.Write(LevelOutputFormat.GetLevelMoniker(_value, format));
         }

src/Serilog/Formatting/Display/Obsolete/LogEventPropertiesValue.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -33,7 +34,7 @@ public LogEventPropertiesValue(MessageTemplate template, IReadOnlyDictionary<str
             _outputTemplate = outputTemplate;
         }
 
-        public override void Render(TextWriter output, string format = null, IFormatProvider formatProvider = null)
+        public override void Render(TextWriter output, string? format = null, IFormatProvider? formatProvider = null)
         {
             PropertiesOutputFormat.Render(_template, _properties, _outputTemplate, output, format, formatProvider);
         }

src/Serilog/Formatting/Display/Obsolete/LogEventPropertyMessageValue.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -31,7 +32,7 @@ public LogEventPropertyMessageValue(MessageTemplate template, IReadOnlyDictionar
             _properties = properties;
         }
 
-        public override void Render(TextWriter output, string format = null, IFormatProvider formatProvider = null)
+        public override void Render(TextWriter output, string? format = null, IFormatProvider? formatProvider = null)
         {
             _template.Render(_properties, output, formatProvider);
         }

src/Serilog/Formatting/Display/PropertiesOutputFormat.cs

@@ -26,7 +26,7 @@ static class PropertiesOutputFormat
     {
         static readonly JsonValueFormatter JsonValueFormatter = new("$type");
 
-        public static void Render(MessageTemplate template, IReadOnlyDictionary<string, LogEventPropertyValue> properties, MessageTemplate outputTemplate, TextWriter output, string format, IFormatProvider? formatProvider = null)
+        public static void Render(MessageTemplate template, IReadOnlyDictionary<string, LogEventPropertyValue> properties, MessageTemplate outputTemplate, TextWriter output, string? format, IFormatProvider? formatProvider = null)
         {
             if (format?.Contains("j") == true)
             {

src/Serilog/Formatting/Json/JsonFormatter.cs

@@ -354,7 +354,7 @@ protected virtual void WriteDictionary(IReadOnlyDictionary<ScalarValue, LogEvent
         /// Writes out a json property with the specified value on output writer
         /// </summary>
         [Obsolete(ExtensionPointObsoletionMessage)]
-        protected virtual void WriteJsonProperty(string name, object value, ref string precedingDelimiter, TextWriter output)
+        protected virtual void WriteJsonProperty(string name, object? value, ref string precedingDelimiter, TextWriter output)
         {
             output.Write(precedingDelimiter);
             output.Write("\"");

src/Serilog/Parsing/MessageTemplateToken.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -51,6 +52,6 @@ protected MessageTemplateToken(int startIndex)
         /// <param name="output">Output for the rendered string.</param>
         /// <param name="formatProvider">Supplies culture-specific formatting information, or null.</param>
         // ReSharper disable once UnusedMemberInSuper.Global
-        public abstract void Render(IReadOnlyDictionary<string, LogEventPropertyValue> properties, TextWriter output, IFormatProvider formatProvider = null);
+        public abstract void Render(IReadOnlyDictionary<string, LogEventPropertyValue> properties, TextWriter output, IFormatProvider? formatProvider = null);
     }
-}
+}

src/Serilog/Parsing/PropertyToken.cs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
@@ -55,7 +56,7 @@ public PropertyToken(string propertyName, string rawText, string formatObsolete,
         /// <param name="startIndex">The token's start index in the template.</param>
         /// <exception cref="ArgumentNullException">When <paramref name="propertyName"/> is <code>null</code></exception>
         /// <exception cref="ArgumentNullException">When <paramref name="rawText"/> is <code>null</code></exception>
-        public PropertyToken(string propertyName, string rawText, string format = null, Alignment? alignment = null, Destructuring destructuring = Destructuring.Default, int startIndex = -1)
+        public PropertyToken(string propertyName, string rawText, string? format = null, Alignment? alignment = null, Destructuring destructuring = Destructuring.Default, int startIndex = -1)
             : base(startIndex)
         {
             PropertyName = propertyName ?? throw new ArgumentNullException(nameof(propertyName));
@@ -84,7 +85,7 @@ public PropertyToken(string propertyName, string rawText, string format = null,
         /// <param name="formatProvider">Supplies culture-specific formatting information, or null.</param>
         /// <exception cref="ArgumentNullException">When <paramref name="properties"/> is <code>null</code></exception>
         /// <exception cref="ArgumentNullException">When <paramref name="output"/> is <code>null</code></exception>
-        public override void Render(IReadOnlyDictionary<string, LogEventPropertyValue> properties, TextWriter output, IFormatProvider formatProvider = null)
+        public override void Render(IReadOnlyDictionary<string, LogEventPropertyValue> properties, TextWriter output, IFormatProvider? formatProvider = null)
         {
             if (properties == null) throw new ArgumentNullException(nameof(properties));
             if (output == null) throw new ArgumentNullException(nameof(output));
@@ -105,7 +106,7 @@ public override void Render(IReadOnlyDictionary<string, LogEventPropertyValue> p
         /// <summary>
         /// Format applied to the property.
         /// </summary>
-        public string Format { get; }
+        public string? Format { get; }
 
         /// <summary>
         /// Alignment applied to the property.
@@ -143,7 +144,7 @@ public bool TryGetPositionalValue(out int position)
         /// true if the specified object  is equal to the current object; otherwise, false.
         /// </returns>
         /// <param name="obj">The object to compare with the current object. </param><filterpriority>2</filterpriority>
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             return obj is PropertyToken pt &&
                 pt.Destructuring == Destructuring &&