Add %localDate and %localTime to PrefixWriter

README.md

@@ -132,8 +132,10 @@ The prefix pattern is a string with the following placeholders:
 
 | Placeholder      | Effect                                                        | Format                                                     | 
 |------------------|---------------------------------------------------------------|------------------------------------------------------------|
-| `%date`          | The message UTC date                                          | A `DateTime` format string, default: `yyyy-MM-dd`          |
-| `%time`          | The message UTC timestamp                                     | A `TimeSpan` format string, default: `hh\:mm\:ss\.fffffff` |
+| `%date`          | The message date in UTC                                       | A `DateTime` format string, default: `yyyy-MM-dd`          |
+| `%localDate`     | The message date converted to the local time zone             | A `DateTime` format string, default: `yyyy-MM-dd`          |
+| `%time`          | The message timestamp in UTC                                  | A `TimeSpan` format string, default: `hh\:mm\:ss\.fffffff` |
+| `%localTime`     | The message timestamp converted to the local time zone        | A `TimeSpan` format string, default: `hh\:mm\:ss\.fffffff` |
 | `%thread`        | The thread name (or ID) which logged the message              |                                                            |
 | `%level`         | The log level in uppercase                                    | `pad` is equivalent to `5` (the longest level length)      |
 | `%logger`        | The logger name                                               |                                                            | 

src/ZeroLog.Analyzers/Support/CompilerServices.cs

@@ -0,0 +1,5 @@
+// ReSharper disable once CheckNamespace
+
+namespace System.Runtime.CompilerServices;
+
+internal static class IsExternalInit;

src/ZeroLog.Impl.Full/Formatting/DefaultFormatter.cs

@@ -29,7 +29,9 @@ public sealed class DefaultFormatter : Formatter
     /// The pattern is a string containing placeholders:
     /// <list type="table">
     /// <item><term><c>%date</c></term><description>The message UTC date (default format: <c>yyyy-MM-dd</c>).</description></item>
+    /// <item><term><c>%localDate</c></term><description>The message local date (default format: <c>yyyy-MM-dd</c>).</description></item>
     /// <item><term><c>%time</c></term><description>The message UTC timestamp (default format: <c>hh\:mm\:ss\.fffffff</c>).</description></item>
+    /// <item><term><c>%localTime</c></term><description>The message local timestamp (default format: <c>hh\:mm\:ss\.fffffff</c>).</description></item>
     /// <item><term><c>%thread</c></term><description>The thread name (or ID) which logged the message.</description></item>
     /// <item><term><c>%level</c></term><description>The log level in uppercase (specify the <c>pad</c> format to make each level 5 characters wide).</description></item>
     /// <item><term><c>%logger</c></term><description>The logger name.</description></item>

src/ZeroLog.Impl.Full/Formatting/PrefixWriter.cs

@@ -30,6 +30,8 @@ internal class PrefixWriter
 
     public string Pattern { get; }
 
+    internal TimeZoneInfo? LocalTimeZone { get; init; } // For unit tests
+
     [SuppressMessage("ReSharper", "ConvertToPrimaryConstructor")]
     public PrefixWriter(string pattern)
     {
@@ -75,7 +77,9 @@ private static IEnumerable<PatternPart> ParsePattern(string pattern)
             var part = placeholderType.ToLowerInvariant() switch
             {
                 "date"          => new PatternPart(PatternPartType.Date, format),
+                "localdate"     => new PatternPart(PatternPartType.LocalDate, format),
                 "time"          => new PatternPart(PatternPartType.Time, format),
+                "localtime"     => new PatternPart(PatternPartType.LocalTime, format),
                 "thread"        => new PatternPart(PatternPartType.Thread, format),
                 "level"         => new PatternPart(PatternPartType.Level, format),
                 "logger"        => new PatternPart(PatternPartType.Logger, format),
@@ -106,25 +110,27 @@ private static PatternPart ValidatePart(PatternPart part, string placeholderType
             }
 
             case PatternPartType.Date:
+            case PatternPartType.LocalDate:
             {
                 if (part.Format is not null)
                 {
                     _ = new DateTime(2020, 01, 01, 03, 04, 05, 06).ToString(part.Format, CultureInfo.InvariantCulture);
                     return part;
                 }
 
-                return new PatternPart(PatternPartType.Date, "yyyy-MM-dd", null);
+                return new PatternPart(part.Type, "yyyy-MM-dd", null);
             }
 
             case PatternPartType.Time:
+            case PatternPartType.LocalTime:
             {
                 if (part.Format is not null)
                 {
                     _ = new TimeSpan(0, 01, 02, 03, 04).ToString(part.Format, CultureInfo.InvariantCulture);
                     return part;
                 }
 
-                return new PatternPart(PatternPartType.Time, @"hh\:mm\:ss\.fffffff", null);
+                return new PatternPart(part.Type, @"hh\:mm\:ss\.fffffff", null);
             }
 
             case PatternPartType.Level:
@@ -224,6 +230,14 @@ public void WritePrefix(LoggedMessage message, Span<char> destination, out int c
                     break;
                 }
 
+                case PatternPartType.LocalDate:
+                {
+                    if (!builder.TryAppend(ToLocalDate(message.Timestamp), part.Format))
+                        goto endOfLoop;
+
+                    break;
+                }
+
                 case PatternPartType.Time:
                 {
                     if (!builder.TryAppend(message.Timestamp.TimeOfDay, part.Format))
@@ -232,6 +246,14 @@ public void WritePrefix(LoggedMessage message, Span<char> destination, out int c
                     break;
                 }
 
+                case PatternPartType.LocalTime:
+                {
+                    if (!builder.TryAppend(ToLocalDate(message.Timestamp).TimeOfDay, part.Format))
+                        goto endOfLoop;
+
+                    break;
+                }
+
                 case PatternPartType.Thread:
                 {
                     var thread = message.Thread;
@@ -311,13 +333,18 @@ public void WritePrefix(LoggedMessage message, Span<char> destination, out int c
         charsWritten = builder.Length;
     }
 
+    private DateTime ToLocalDate(DateTime value)
+        => LocalTimeZone is not null ? TimeZoneInfo.ConvertTimeFromUtc(value, LocalTimeZone) : value.ToLocalTime();
+
 #endif
 
     private enum PatternPartType
     {
         String,
         Date,
+        LocalDate,
         Time,
+        LocalTime,
         Thread,
         Level,
         Logger,

src/ZeroLog.Tests/Formatting/PrefixWriterTests.cs

@@ -15,7 +15,9 @@ public class PrefixWriterTests
     [TestCase("", "")]
     [TestCase("foo", "foo")]
     [TestCase("%date", "2020-01-02")]
+    [TestCase("%localDate", "2020-01-01")]
     [TestCase("%time", "03:04:05.0060000")]
+    [TestCase("%localTime", "17:04:05.0060000")]
     [TestCase("%level", "INFO")]
     [TestCase("%logger", "Foo.Bar.TestLog")]
     [TestCase("%loggerCompact", "FB.TestLog")]
@@ -31,6 +33,7 @@ public class PrefixWriterTests
     [TestCase("%{level}Bar", "INFOBar")]
     [TestCase("%{level}%{logger}", "INFOFoo.Bar.TestLog")]
     [TestCase("%{date:dd MM yyyy}", "02 01 2020")]
+    [TestCase("%{localDate:dd MM yyyy HH mm ss}", "01 01 2020 17 04 05")]
     [TestCase("%{date:lol}", "lol")]
     [TestCase("%{time:hh\\:mm}", "03:04")]
     [TestCase("%{level:pad}", "INFO ")]
@@ -42,7 +45,12 @@ public class PrefixWriterTests
     [TestCase("abc%{column:10}def%{column:15}ghi", "abc       def  ghi")]
     public void should_write_prefix(string pattern, string expectedResult)
     {
-        var prefixWriter = new PrefixWriter(pattern);
+        var localTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Etc/GMT+10");
+
+        var prefixWriter = new PrefixWriter(pattern)
+        {
+            LocalTimeZone = localTimeZone
+        };
 
         var logMessage = new LogMessage("Foo");
         logMessage.Initialize(new Log("Foo.Bar.TestLog"), LogLevel.Info);