refactor(internal/storage/RequestWriter/WriteReq): wtf is that error handling

internal/storage/writer.go

@@ -1,6 +1,9 @@
 package storage
 
 import (
+	"database/sql"
+	"errors"
+	"fmt"
 	"time"
 )
 
@@ -14,29 +17,32 @@ func WriteReq(db *RequestWriter, resultCh <-chan *LogEntry) {
 	defer ticker.Stop()
 
 	flush := func() {
+		defer db.logger.Debug("Flushed batch", "count", len(batch))
+		err := func() (err error) {
 			if len(batch) == 0 {
-			return
+				return nil
 			}
 
 			tx, err := db.db.Begin()
 			if err != nil {
-			db.logger.Error("Failed to begin transaction", "error", err)
-			return
+				return fmt.Errorf("Failed to begin transaction: %w", err)
 			}
+			defer func() {
+				if rollbackErr := tx.Rollback(); rollbackErr != nil && !errors.Is(rollbackErr, sql.ErrTxDone) {
+					err = errors.Join(err, fmt.Errorf("Failed to rollback transaction: %w", rollbackErr))
+				}
+			}()
 
 			stmt, err := tx.Prepare(
 				"INSERT INTO requests (service, ip, path, method, status, created_at) VALUES (?, ?, ?, ?, ?, ?)",
 			)
 			if err != nil {
-			db.logger.Error("Failed to prepare statement", "error", err)
-			if rollbackErr := tx.Rollback(); rollbackErr != nil {
-				db.logger.Error("Failed to rollback transaction", "error", rollbackErr)
-			}
-			return
+				err = fmt.Errorf("Failed to prepare statement: %w", err)
+				return err
 			}
 			defer func() {
 				if closeErr := stmt.Close(); closeErr != nil {
-				db.logger.Error("Failed to close statement", "error", closeErr)
+					err = errors.Join(err, fmt.Errorf("Failed to close statement: %w", closeErr))
 				}
 			}()
 
@@ -50,17 +56,20 @@ func WriteReq(db *RequestWriter, resultCh <-chan *LogEntry) {
 					time.Now().Format(time.RFC3339),
 				)
 				if err != nil {
-				db.logger.Error("Failed to insert entry", "error", err)
+					db.logger.Error(fmt.Errorf("Failed to insert entry: %w", err).Error())
 				}
 			}
 
 			if err := tx.Commit(); err != nil {
-			db.logger.Error("Failed to commit transaction", "error", err)
-			return
+				return fmt.Errorf("Failed to commit transaction: %w", err)
 			}
 
-		db.logger.Debug("Flushed batch", "count", len(batch))
 			batch = batch[:0]
+			return err
+		}()
+		if err != nil {
+			db.logger.Error(err.Error())
+		}
 	}
 
 	for {