Added support for overriding color and name for level along with cust…

…om levels.

handler.go

@@ -84,6 +84,12 @@ var (
 	defaultTimeFormat = time.StampMilli
 )
 
+// LevelMeta contains the name and color of a level.
+type LevelMeta struct {
+	Name  string
+	Color string
+}
+
 // Options for a slog.Handler that writes tinted logs. A zero Options consists
 // entirely of default values.
 //
@@ -95,6 +101,10 @@ type Options struct {
 	// Minimum level to log (Default: slog.LevelInfo)
 	Level slog.Leveler
 
+	// LevelMeta is a map of level to its name and color. If set, it overrides
+	// the default level names and colors.
+	LevelMeta map[slog.Level]LevelMeta
+
 	// ReplaceAttr is called to rewrite each non-group attribute before it is logged.
 	// See https://pkg.go.dev/log/slog#HandlerOptions for details.
 	ReplaceAttr func(groups []string, attr slog.Attr) slog.Attr
@@ -122,6 +132,11 @@ func NewHandler(w io.Writer, opts *Options) slog.Handler {
 	if opts.Level != nil {
 		h.level = opts.Level
 	}
+
+	if len(opts.LevelMeta) > 0 {
+		h.levelMeta = opts.LevelMeta
+	}
+
 	h.replaceAttr = opts.ReplaceAttr
 	if opts.TimeFormat != "" {
 		h.timeFormat = opts.TimeFormat
@@ -141,6 +156,7 @@ type handler struct {
 
 	addSource   bool
 	level       slog.Leveler
+	levelMeta   map[slog.Level]LevelMeta
 	replaceAttr func([]string, slog.Attr) slog.Attr
 	timeFormat  string
 	noColor     bool
@@ -283,6 +299,10 @@ func (h *handler) appendTime(buf *buffer, t time.Time) {
 }
 
 func (h *handler) appendLevel(buf *buffer, level slog.Level) {
+	if h.applyMeta(buf, level) {
+		return
+	}
+
 	switch {
 	case level < slog.LevelInfo:
 		buf.WriteString("DBG")
@@ -305,6 +325,19 @@ func (h *handler) appendLevel(buf *buffer, level slog.Level) {
 	}
 }
 
+func (h *handler) applyMeta(buf *buffer, level slog.Level) bool {
+	lvlMeta, ok := h.levelMeta[level]
+	if !ok {
+		return false
+	}
+
+	buf.WriteStringIf(!h.noColor, lvlMeta.Color)
+	buf.WriteString(lvlMeta.Name)
+	buf.WriteStringIf(!h.noColor, ansiReset)
+
+	return true
+}
+
 func appendLevelDelta(buf *buffer, delta slog.Level) {
 	if delta == 0 {
 		return

handler_test.go

@@ -18,16 +18,31 @@ import (
 
 var faketime = time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC)
 
+const CustomLevel slog.Level = -6
+
 func Example() {
+	lvlMeta := map[slog.Level]tint.LevelMeta{
+		CustomLevel: {
+			Name:  "TEST",
+			Color: "\033[95m",
+		},
+		slog.LevelDebug: {
+			Name:  "DBG",
+			Color: "\033[94m",
+		},
+	}
+
 	slog.SetDefault(slog.New(tint.NewHandler(os.Stderr, &tint.Options{
-		Level:      slog.LevelDebug,
+		Level:      CustomLevel,
+		LevelMeta:  lvlMeta,
 		TimeFormat: time.Kitchen,
 	})))
 
 	slog.Info("Starting server", "addr", ":8080", "env", "production")
 	slog.Debug("Connected to DB", "db", "myapp", "host", "localhost:5432")
 	slog.Warn("Slow request", "method", "GET", "path", "/users", "duration", 497*time.Millisecond)
 	slog.Error("DB connection lost", tint.Err(errors.New("connection reset")), "db", "myapp")
+	slog.Log(context.Background(), CustomLevel, "Custom level message")
 	// Output:
 }
 
@@ -344,6 +359,21 @@ func TestHandler(t *testing.T) {
 			},
 			Want: `Nov 10 23:00:00.000 INF test key="{A:123 B:<nil>}"`,
 		},
+		{ // https://github.com/lmittmann/tint/issues/37
+			Opts: &tint.Options{
+				Level: slog.LevelDebug,
+				LevelMeta: map[slog.Level]tint.LevelMeta{
+					slog.LevelDebug: {
+						Name:  "MyDebug",
+						Color: "\033[32m",
+					},
+				},
+			},
+			F: func(l *slog.Logger) {
+				l.Debug("test")
+			},
+			Want: `Nov 10 23:00:00.000 MyDebug test`,
+		},
 	}
 
 	for i, test := range tests {