feat: support customization of json marshal

log/logger.go

@@ -74,6 +74,20 @@ func NewLogger(dst io.Writer, options ...Option) Logger {
 	for _, opt := range options {
 		opt(&logCfg)
 	}
+	if logCfg.JSONMarshal != nil {
+		zerolog.InterfaceMarshalFunc = func(i interface{}) ([]byte, error) {
+			switch v := i.(type) {
+			case json.Marshaler:
+				return logCfg.JSONMarshal(i)
+			case encoding.TextMarshaler:
+				return logCfg.JSONMarshal(i)
+			case fmt.Stringer:
+				return logCfg.JSONMarshal(v.String())
+			default:
+				return logCfg.JSONMarshal(i)
+			}
+		}
+	}
 
 	output := dst
 	if !logCfg.OutputJSON {

log/options.go

@@ -1,29 +1,32 @@
 package log
 
 import (
+	"encoding/json"
 	"time"
 
 	"github.com/rs/zerolog"
 )
 
 // defaultConfig has all the options disabled, except Color and TimeFormat
 var defaultConfig = Config{
-	Level:      zerolog.NoLevel,
-	Filter:     nil,
-	OutputJSON: false,
-	Color:      true,
-	StackTrace: false,
-	TimeFormat: time.Kitchen,
+	Level:       zerolog.NoLevel,
+	Filter:      nil,
+	OutputJSON:  false,
+	Color:       true,
+	StackTrace:  false,
+	TimeFormat:  time.Kitchen,
+	JSONMarshal: json.Marshal,
 }
 
 // Config defines configuration for the logger.
 type Config struct {
-	Level      zerolog.Level
-	Filter     FilterFunc
-	OutputJSON bool
-	Color      bool
-	StackTrace bool
-	TimeFormat string
+	Level       zerolog.Level
+	Filter      FilterFunc
+	OutputJSON  bool
+	Color       bool
+	StackTrace  bool
+	TimeFormat  string
+	JSONMarshal func(v interface{}) ([]byte, error)
 }
 
 type Option func(*Config)
@@ -87,3 +90,10 @@ func TraceOption(val bool) Option {
 		cfg.StackTrace = val
 	}
 }
+
+// JSONMarshalOption add option to configure custom JSON encoding
+func JSONMarshalOption(f func(v interface{}) ([]byte, error)) Option {
+	return func(cfg *Config) {
+		cfg.JSONMarshal = f
+	}
+}