refactor: made logger a dependency

backend/internal/logger/logger.go

@@ -1,17 +1,31 @@
 package logger
+
 import (
 	"sync"
 
-	"go.uber.org/zap"
 	"easywish/config"
+
+	"go.uber.org/zap"
 )
 
+type Logger interface {
+	Get() *zap.Logger	
+	Sync() error
+}
+
+type loggerImpl struct {
+}
+
+func NewLogger() Logger {
+	return &loggerImpl{}
+}
+
 var (
 	logger *zap.Logger
 	once   sync.Once
 )
 
-func GetLogger() *zap.Logger {
+func (l *loggerImpl) Get() *zap.Logger {
 	once.Do(func() {
 		var err error
 		cfg := config.GetConfig()
@@ -28,6 +42,6 @@ func GetLogger() *zap.Logger {
 	return logger
 }
 
-func Sync() error {
+func (l *loggerImpl) Sync() error {
 	return logger.Sync()
 }