feat: add json log field

log/fields.go

@@ -1,28 +1,44 @@
 package log
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"go.uber.org/zap"
 )
 
 const (
+	// NumKey - generic number attribute
 	NumKey = "num"
-
+	// NameKey - generic name attribute
 	NameKey = "name"
-
-	// ValueKey represents a generic value attribute.
+	// ValueKey - generic value attribute
 	ValueKey = "value"
+	// JSONKey - generic json attribute
+	JSONKey = "json"
 )
 
+// FNum - returns zap field
 func FNum(num int) zap.Field {
 	return zap.Int(NumKey, num)
 }
 
+// FName - returns zap field
 func FName(name string) zap.Field {
 	return zap.String(NameKey, name)
 }
 
+// FValue - returns zap field
 func FValue(value interface{}) zap.Field {
 	return zap.String(ValueKey, fmt.Sprintf("%v", value))
 }
+
+// FJSON - returns zap field
+func FJSON(v interface{}) zap.Field {
+	if out, err := json.Marshal(v); err != nil {
+		return zap.String(JSONKey+"_error", err.Error())
+	} else {
+		raw := json.RawMessage(out)
+		return zap.Any(JSONKey, &raw)
+	}
+}