Log wall-clock time when logging to a stream.

CHANGELOG.md

@@ -10,6 +10,13 @@ The format is based on [Keep a Changelog], and this project adheres to
 [Keep a Changelog]: https://keepachangelog.com/en/1.0.0/
 [Semantic Versioning]: https://semver.org/spec/v2.0.0.html
 
+## [0.2.2] - 2024-07-19
+
+### Changed
+
+- Display a wall-clock time (instead of the duration since the logger was
+  created) when logging to an `io.Writer`.'
+
 ## [0.2.1] - 2024-07-19
 
 ### Changed

spruce.go

@@ -6,14 +6,13 @@ import (
 	"log/slog"
 	"slices"
 	"strings"
-	"time"
 )
 
 type handler struct {
-	log    func(string) error
-	attrs  []slog.Attr
-	groups []string
-	epoch  time.Time
+	log       func(string) error
+	attrs     []slog.Attr
+	groups    []string
+	writeTime func(*strings.Builder, slog.Record)
 }
 
 func (h *handler) Enabled(context.Context, slog.Level) bool {
@@ -53,15 +52,10 @@ func (h *handler) Handle(_ context.Context, rec slog.Record) error {
 
 	level := rec.Level.String()
 
-	elapsed := rec.Time.Sub(h.epoch)
-
 	buf.WriteByte('[')
 	buf.WriteString(level)
 	buf.WriteByte(' ')
-	if elapsed > 0 {
-		buf.WriteByte('+')
-	}
-	buf.WriteString(elapsed.String())
+	h.writeTime(buf, rec)
 
 	for i, g := range h.groups {
 		if i == 0 {
@@ -142,18 +136,18 @@ func writeAttrs(
 
 func (h *handler) WithAttrs(attrs []slog.Attr) slog.Handler {
 	return &handler{
-		log:    h.log,
-		attrs:  append(slices.Clone(h.attrs), attrs...),
-		groups: h.groups,
-		epoch:  h.epoch,
+		log:       h.log,
+		attrs:     append(slices.Clone(h.attrs), attrs...),
+		groups:    h.groups,
+		writeTime: h.writeTime,
 	}
 }
 
 func (h *handler) WithGroup(name string) slog.Handler {
 	return &handler{
-		log:    h.log,
-		attrs:  h.attrs,
-		groups: append(slices.Clone(h.groups), name),
-		epoch:  h.epoch,
+		log:       h.log,
+		attrs:     h.attrs,
+		groups:    append(slices.Clone(h.groups), name),
+		writeTime: h.writeTime,
 	}
 }

stream.go

@@ -3,6 +3,7 @@ package spruce
 import (
 	"io"
 	"log/slog"
+	"strings"
 	"time"
 )
 
@@ -25,6 +26,10 @@ func NewStreamHandler(w io.Writer) slog.Handler {
 			}
 			return nil
 		},
-		epoch: time.Now(),
+		writeTime: func(w *strings.Builder, rec slog.Record) {
+			w.WriteString(
+				rec.Time.Format(time.RFC3339),
+			)
+		},
 	}
 }

testing.go

@@ -2,6 +2,7 @@ package spruce
 
 import (
 	"log/slog"
+	"strings"
 	"testing"
 	"time"
 )
@@ -20,11 +21,19 @@ func NewTestLogger(t TestingT) *slog.Logger {
 
 // NewTestHandler returns a new [slog.Handler] that writes to t.
 func NewTestHandler(t TestingT) slog.Handler {
+	epoch := time.Now()
+
 	return &handler{
 		log: func(s string) error {
 			t.Log(s)
 			return nil
 		},
-		epoch: time.Now(),
+		writeTime: func(w *strings.Builder, rec slog.Record) {
+			elapsed := rec.Time.Sub(epoch)
+			if elapsed > 0 {
+				w.WriteByte('+')
+			}
+			w.WriteString(elapsed.String())
+		},
 	}
 }