feat: add handler for log/slog in go1.21 (#548)

_examples/slog/demo/main.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"github.com/pterm/pterm"
+	"log/slog"
+)
+
+func main() {
+	handler := pterm.NewSlogHandler(&pterm.DefaultLogger)
+	logger := slog.New(handler)
+
+	logger.Debug("This is a debug message that won't show")
+	pterm.DefaultLogger.Level = pterm.LogLevelDebug // Enable debug messages
+	logger.Debug("This is a debug message", "changedLevel", true)
+	logger.Info("This is an info message")
+	logger.Warn("This is a warning message")
+	logger.Error("This is an error message")
+}

slog_handler.go

@@ -0,0 +1,82 @@
+package pterm
+
+import (
+	"context"
+	"log/slog"
+)
+
+type SlogHandler struct {
+	logger *Logger
+	attrs  []slog.Attr
+}
+
+// Enabled returns true if the given level is enabled.
+func (s *SlogHandler) Enabled(ctx context.Context, level slog.Level) bool {
+	switch level {
+	case slog.LevelDebug:
+		return s.logger.CanPrint(LogLevelDebug)
+	case slog.LevelInfo:
+		return s.logger.CanPrint(LogLevelInfo)
+	case slog.LevelWarn:
+		return s.logger.CanPrint(LogLevelWarn)
+	case slog.LevelError:
+		return s.logger.CanPrint(LogLevelError)
+	}
+	return false
+}
+
+// Handle handles the given record.
+func (s *SlogHandler) Handle(ctx context.Context, record slog.Record) error {
+	level := record.Level
+	message := record.Message
+
+	// Convert slog Attrs to a map.
+	keyValsMap := make(map[string]interface{})
+
+	record.Attrs(func(attr slog.Attr) bool {
+		keyValsMap[attr.Key] = attr.Value
+		return true
+	})
+
+	for _, attr := range s.attrs {
+		keyValsMap[attr.Key] = attr.Value
+	}
+
+	args := s.logger.ArgsFromMap(keyValsMap)
+
+	// Wrapping args inside another slice to match [][]LoggerArgument
+	argsWrapped := [][]LoggerArgument{args}
+
+	switch level {
+	case slog.LevelDebug:
+		s.logger.Debug(message, argsWrapped...)
+	case slog.LevelInfo:
+		s.logger.Info(message, argsWrapped...)
+	case slog.LevelWarn:
+		s.logger.Warn(message, argsWrapped...)
+	case slog.LevelError:
+		s.logger.Error(message, argsWrapped...)
+	default:
+		s.logger.Print(message, argsWrapped...)
+	}
+
+	return nil
+}
+
+// WithAttrs returns a new handler with the given attributes.
+func (s *SlogHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
+	newS := *s
+	newS.attrs = attrs
+	return &newS
+}
+
+// WithGroup is not yet supported.
+func (s *SlogHandler) WithGroup(name string) slog.Handler {
+	// Grouping is not yet supported by pterm.
+	return s
+}
+
+// NewSlogHandler returns a new logging handler that can be intrgrated with log/slog.
+func NewSlogHandler(logger *Logger) *SlogHandler {
+	return &SlogHandler{logger: logger}
+}