Implement use slog.Leveler and slog.LevelVar. And adding custom log level

json.go

@@ -4,6 +4,7 @@
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"time"
 )
 
@@ -38,6 +39,10 @@
 	case LevelKey:
 		if level, ok := value.(Level); ok {
 			jw.objectItem(LevelKey, level.String())
+		} else if level, ok := value.(slog.Leveler); ok {
+			if lvl, ok := Levels[int(level.Level())]; ok {
+				jw.objectItem(LevelKey, lvl.String())
+			}
 		}
 	case CallerKey:
 		if caller, ok := value.(string); ok {

json_test.go

@@ -6,11 +6,30 @@ import (
 	"fmt"
 	"path/filepath"
 	"runtime"
+	"strings"
 	"testing"
 
+	"github.com/charmbracelet/lipgloss"
 	"github.com/stretchr/testify/require"
 )
 
+func TestJsonCustomLevelWithStyle(t *testing.T) {
+	var buf bytes.Buffer
+	l := New(&buf)
+	styles := DefaultStyles()
+	Levels[int(Critical)] = Critical
+	styles.Levels[int(Critical)] = lipgloss.NewStyle().
+		SetString(strings.ToUpper(Critical.String())).
+		Bold(true).
+		MaxWidth(4).
+		Foreground(lipgloss.Color("134"))
+	l.SetStyles(styles)
+	l.SetLevel(InfoLevel)
+	l.SetFormatter(JSONFormatter)
+	l.Logf(Critical, "foo")
+	require.Equal(t, "{\"level\":\"crit\",\"msg\":\"foo\"}\n", buf.String())
+}
+
 func TestJson(t *testing.T) {
 	var buf bytes.Buffer
 	l := New(&buf)

level.go

@@ -3,13 +3,16 @@
 import (
 	"errors"
 	"fmt"
+	"log/slog"
 	"math"
 	"strings"
 )
 
 // Level is a logging level.
 type Level int
 
+func (l Level) Level() slog.Level { return slog.Level(l) }
+
 const (
 	// DebugLevel is the debug level.
 	DebugLevel Level = -4
@@ -25,6 +28,14 @@
 	noLevel Level = math.MaxInt
 )
 
+var Levels map[int]fmt.Stringer = map[int]fmt.Stringer{
+	int(DebugLevel): DebugLevel,
+	int(InfoLevel):  InfoLevel,
+	int(WarnLevel):  WarnLevel,
+	int(ErrorLevel): ErrorLevel,
+	int(FatalLevel): FatalLevel,
+}
+
 // String returns the string representation of the level.
 func (l Level) String() string {
 	switch l { //nolint:exhaustive

logger.go

@@ -4,6 +4,7 @@
 	"bytes"
 	"fmt"
 	"io"
+	"log/slog"
 	"os"
 	"runtime"
 	"strings"
@@ -30,7 +31,7 @@
 
 	isDiscard uint32
 
-	level           int64
+	level           *slog.LevelVar
 	prefix          string
 	timeFunc        TimeFunction
 	timeFormat      string
@@ -48,18 +49,18 @@
 }
 
 // Logf logs a message with formatting.
-func (l *Logger) Logf(level Level, format string, args ...interface{}) {
+func (l *Logger) Logf(level slog.Leveler, format string, args ...interface{}) {
 	l.Log(level, fmt.Sprintf(format, args...))
 }
 
 // Log logs the given message with the given keyvals for the given level.
-func (l *Logger) Log(level Level, msg interface{}, keyvals ...interface{}) {
+func (l *Logger) Log(level slog.Leveler, msg interface{}, keyvals ...interface{}) {
 	if atomic.LoadUint32(&l.isDiscard) != 0 {
 		return
 	}
 
 	// check if the level is allowed
-	if atomic.LoadInt64(&l.level) > int64(level) {
+	if l.level.Level() > level.Level() {
 		return
 	}
 
@@ -81,13 +82,13 @@
 	l.handle(level, l.timeFunc(time.Now()), []runtime.Frame{frame}, msg, keyvals...)
 }
 
-func (l *Logger) handle(level Level, ts time.Time, frames []runtime.Frame, msg interface{}, keyvals ...interface{}) {
+func (l *Logger) handle(level slog.Leveler, ts time.Time, frames []runtime.Frame, msg interface{}, keyvals ...interface{}) {
 	var kvs []interface{}
 	if l.reportTimestamp && !ts.IsZero() {
 		kvs = append(kvs, TimestampKey, ts)
 	}
 
-	_, ok := l.styles.Levels[level]
+	_, ok := l.styles.Levels[int(level.Level())]
 	if ok {
 		kvs = append(kvs, LevelKey, level)
 	}
@@ -136,7 +137,7 @@
 	}
 
 	// WriteTo will reset the buffer
 	l.b.WriteTo(l.w) //nolint: errcheck
 }
 
 // Helper marks the calling function as a helper
@@ -226,17 +227,17 @@
 }
 
 // GetLevel returns the current level.
-func (l *Logger) GetLevel() Level {
+func (l *Logger) GetLevel() slog.Leveler {
 	l.mu.RLock()
 	defer l.mu.RUnlock()
-	return Level(l.level)
+	return l.level.Level()
 }
 
 // SetLevel sets the current level.
-func (l *Logger) SetLevel(level Level) {
+func (l *Logger) SetLevel(level slog.Leveler) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
-	atomic.StoreInt64(&l.level, int64(level))
+	l.level.Set(level.Level())
 }
 
 // GetPrefix returns the current prefix.

logger_121.go

@@ -7,7 +7,6 @@
 	"context"
 	"log/slog"
 	"runtime"
-	"sync/atomic"
 )
 
 // type aliases for slog.
@@ -17,7 +16,7 @@
 	slogLogValuer = slog.LogValuer
 )
 
 var slogAnyValue = slog.AnyValue
 
 const slogKindGroup = slog.KindGroup
 
@@ -25,7 +24,7 @@
 //
 // Implements slog.Handler.
 func (l *Logger) Enabled(_ context.Context, level slog.Level) bool {
-	return atomic.LoadInt64(&l.level) <= int64(level)
+	return l.level.Level() <= level
 }
 
 // Handle handles the Record. It will only be called if Enabled returns true.
@@ -44,7 +43,7 @@
 	// Get the caller frame using the record's PC.
 	frames := runtime.CallersFrames([]uintptr{record.PC})
 	frame, _ := frames.Next()
-	l.handle(Level(record.Level), l.timeFunc(record.Time), []runtime.Frame{frame}, record.Message, fields...)
+	l.handle(record.Level, l.timeFunc(record.Time), []runtime.Frame{frame}, record.Message, fields...)
 	return nil
 }
 

logger_no121.go

@@ -41,7 +41,7 @@ func (l *Logger) Handle(_ context.Context, record slog.Record) error {
 	// Get the caller frame using the record's PC.
 	frames := runtime.CallersFrames([]uintptr{record.PC})
 	frame, _ := frames.Next()
-	l.handle(Level(record.Level), l.timeFunc(record.Time), []runtime.Frame{frame}, record.Message, fields...)
+	l.handle(record.Level, l.timeFunc(record.Time), []runtime.Frame{frame}, record.Message, fields...)
 	return nil
 }
 

logger_test.go

@@ -4,10 +4,13 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"log/slog"
+	"strings"
 	"sync"
 	"testing"
 	"time"
 
+	"github.com/charmbracelet/lipgloss"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -279,9 +282,31 @@ func TestRace(t *testing.T) {
 
 func TestCustomLevel(t *testing.T) {
 	var buf bytes.Buffer
-	level500 := Level(500)
+	level500 := slog.Level(500)
 	l := New(&buf)
 	l.SetLevel(level500)
 	l.Logf(level500, "foo")
 	assert.Equal(t, "foo\n", buf.String())
 }
+
+type CriticalLevel int
+
+func (l CriticalLevel) Level() slog.Level { return slog.Level(l) }
+func (l CriticalLevel) String() string    { return "crit" }
+
+const Critical CriticalLevel = 600
+
+func TestCustomLevelWithStyle(t *testing.T) {
+	var buf bytes.Buffer
+	l := New(&buf)
+	styles := DefaultStyles()
+	styles.Levels[int(Critical)] = lipgloss.NewStyle().
+		SetString(strings.ToUpper(Critical.String())).
+		Bold(true).
+		MaxWidth(4).
+		Foreground(lipgloss.Color("134"))
+	l.SetStyles(styles)
+	l.SetLevel(InfoLevel)
+	l.Logf(Critical, "foo")
+	assert.Equal(t, "CRIT foo\n", buf.String())
+}

options.go

@@ -2,6 +2,7 @@ package log
 
 import (
 	"fmt"
+	"log/slog"
 	"time"
 )
 
@@ -43,7 +44,7 @@ type Options struct {
 	// TimeFormat is the time format for the logger. The default is "2006/01/02 15:04:05".
 	TimeFormat string
 	// Level is the level for the logger. The default is InfoLevel.
-	Level Level
+	Level slog.Leveler
 	// Prefix is the prefix for the logger. The default is no prefix.
 	Prefix string
 	// ReportTimestamp is whether the logger should report the timestamp. The default is false.

options_test.go

@@ -16,7 +16,7 @@ func TestOptions(t *testing.T) {
 		Fields:       []interface{}{"foo", "bar"},
 	}
 	logger := NewWithOptions(io.Discard, opts)
-	require.Equal(t, ErrorLevel, logger.GetLevel())
+	require.Equal(t, opts.Level, Level(logger.GetLevel().Level()))
 	require.True(t, logger.reportCaller)
 	require.False(t, logger.reportTimestamp)
 	require.Equal(t, []interface{}{"foo", "bar"}, logger.fields)

pkg.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"log/slog"
 	"os"
 	"sync"
 	"sync/atomic"
@@ -52,7 +53,7 @@ func NewWithOptions(w io.Writer, o Options) *Logger {
 		b:               bytes.Buffer{},
 		mu:              &sync.RWMutex{},
 		helpers:         &sync.Map{},
-		level:           int64(o.Level),
+		level:           nil,
 		reportTimestamp: o.ReportTimestamp,
 		reportCaller:    o.ReportCaller,
 		prefix:          o.Prefix,
@@ -65,7 +66,18 @@ func NewWithOptions(w io.Writer, o Options) *Logger {
 	}
 
 	l.SetOutput(w)
-	l.SetLevel(Level(l.level))
+	switch o.Level.(type) {
+	case *slog.LevelVar:
+		l.level = o.Level.(*slog.LevelVar)
+	default:
+		lvl := new(slog.LevelVar)
+		if o.Level == nil {
+			lvl.Set(slog.LevelInfo)
+		} else {
+			lvl.Set(o.Level.Level())
+		}
+		l.level = lvl
+	}
 	l.SetStyles(DefaultStyles())
 
 	if l.callerFormatter == nil {
@@ -99,7 +111,7 @@ func SetLevel(level Level) {
 }
 
 // GetLevel returns the level for the default logger.
-func GetLevel() Level {
+func GetLevel() slog.Leveler {
 	return Default().GetLevel()
 }
 

pkg_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"log/slog"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -197,7 +198,7 @@ func TestWith(t *testing.T) {
 
 func TestGetLevel(t *testing.T) {
 	SetLevel(InfoLevel)
-	assert.Equal(t, InfoLevel, GetLevel())
+	assert.Equal(t, slog.Level(InfoLevel), GetLevel())
 }
 
 func TestPrefix(t *testing.T) {

styles.go

@@ -30,7 +30,7 @@ type Styles struct {
 	Separator lipgloss.Style
 
 	// Levels are the styles for each level.
-	Levels map[Level]lipgloss.Style
+	Levels map[int]lipgloss.Style
 
 	// Keys overrides styles for specific keys.
 	Keys map[string]lipgloss.Style
@@ -49,28 +49,28 @@ func DefaultStyles() *Styles {
 		Key:       lipgloss.NewStyle().Faint(true),
 		Value:     lipgloss.NewStyle(),
 		Separator: lipgloss.NewStyle().Faint(true),
-		Levels: map[Level]lipgloss.Style{
-			DebugLevel: lipgloss.NewStyle().
+		Levels: map[int]lipgloss.Style{
+			int(DebugLevel): lipgloss.NewStyle().
 				SetString(strings.ToUpper(DebugLevel.String())).
 				Bold(true).
 				MaxWidth(4).
 				Foreground(lipgloss.Color("63")),
-			InfoLevel: lipgloss.NewStyle().
+			int(InfoLevel): lipgloss.NewStyle().
 				SetString(strings.ToUpper(InfoLevel.String())).
 				Bold(true).
 				MaxWidth(4).
 				Foreground(lipgloss.Color("86")),
-			WarnLevel: lipgloss.NewStyle().
+			int(WarnLevel): lipgloss.NewStyle().
 				SetString(strings.ToUpper(WarnLevel.String())).
 				Bold(true).
 				MaxWidth(4).
 				Foreground(lipgloss.Color("192")),
-			ErrorLevel: lipgloss.NewStyle().
+			int(ErrorLevel): lipgloss.NewStyle().
 				SetString(strings.ToUpper(ErrorLevel.String())).
 				Bold(true).
 				MaxWidth(4).
 				Foreground(lipgloss.Color("204")),
-			FatalLevel: lipgloss.NewStyle().
+			int(FatalLevel): lipgloss.NewStyle().
 				SetString(strings.ToUpper(FatalLevel.String())).
 				Bold(true).
 				MaxWidth(4).

text.go

@@ -3,6 +3,7 @@
 import (
 	"fmt"
 	"io"
+	"log/slog"
 	"strings"
 	"sync"
 	"time"
@@ -160,7 +161,7 @@
 
 func writeSpace(w io.Writer, first bool) {
 	if !first {
 		w.Write([]byte{' '}) //nolint: errcheck
 	}
 }
 
@@ -181,9 +182,9 @@
 				l.b.WriteString(ts)
 			}
 		case LevelKey:
-			if level, ok := keyvals[i+1].(Level); ok {
+			if level, ok := keyvals[i+1].(slog.Leveler); ok {
 				var lvl string
-				lvlStyle, ok := st.Levels[level]
+				lvlStyle, ok := st.Levels[int(level.Level())]
 				if !ok {
 					continue
 				}