feat: new RollbackOnError method added for transactional db helper and integrated into auth service

backend/internal/database/helper.go

@@ -1,17 +1,17 @@
 // Copyright (c) 2025 Nikolai Papin
-// 
+//
 // This file is part of Easywish
-// 
+//
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
 // the Free Software Foundation, either version 3 of the License, or
 // (at your option) any later version.
-// 
+//
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 // the GNU General Public License for more details.
-// 
+//
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
@@ -26,18 +26,19 @@ import (
 type DbHelperTransaction interface {
 	Commit() error
 	Rollback() error
+	RollbackOnError(err error) error
 }
 
 type DbHelper struct {
-	CTX       context.Context
-	Queries   Queries
+	CTX     context.Context
+	Queries Queries
 }
 
 type dbHelperTransactionImpl struct {
-	CTX       context.Context
-	TXlessQueries   Queries
-	TX        pgx.Tx
-	TXQueries Queries
+	CTX           context.Context
+	TXlessQueries Queries
+	TX            pgx.Tx
+	TXQueries     Queries
 }
 
 func NewDbHelper(dbContext DbContext) DbHelper {
@@ -64,10 +65,10 @@ func NewDbHelperTransaction(dbContext DbContext) (DbHelperTransaction, *dbHelper
 	txQueries := queries.WithTx(tx)
 
 	obj := &dbHelperTransactionImpl{
-		CTX:       ctx,
-		TXlessQueries:   *queries,
-		TX:        tx,
-		TXQueries: *txQueries,
+		CTX:           ctx,
+		TXlessQueries: *queries,
+		TX:            tx,
+		TXQueries:     *txQueries,
 	}
 
 	return obj, obj, nil
@@ -81,7 +82,7 @@ func (d *dbHelperTransactionImpl) Commit() error {
 		errRollback := d.TX.Rollback(d.CTX)
 
 		if errRollback != nil {
-			return errRollback 
+			return errRollback
 		}
 
 		return errCommit
@@ -98,3 +99,11 @@ func (d *dbHelperTransactionImpl) Rollback() error {
 	}
 	return nil
 }
+
+// RollbackOnError implements DbHelperTransaction.
+func (d *dbHelperTransactionImpl) RollbackOnError(err error) error {
+	if err != nil {
+		return d.Rollback()
+	}
+	return nil
+}

backend/internal/services/auth.go

@@ -66,7 +66,7 @@ func (a *authServiceImpl) RegistrationBegin(request models.RegistrationBeginRequ
 	var err error
 
 	helper, db, _ := database.NewDbHelperTransaction(a.dbctx)
-  defer helper.Rollback()
+  defer helper.RollbackOnError(err)
 
 	// TODO: check occupation with redis
 
@@ -199,7 +199,7 @@ func (a *authServiceImpl) RegistrationComplete(request models.RegistrationComple
 	var err error
 
 	helper, db, _ := database.NewDbHelperTransaction(a.dbctx)
-	defer helper.Rollback()
+	defer helper.RollbackOnError(err)
 
 	user, err = db.TXQueries.GetUserByUsername(db.CTX, request.Username)
 
@@ -334,11 +334,10 @@ func (a *authServiceImpl) RegistrationComplete(request models.RegistrationComple
 func (a *authServiceImpl) Login(request models.LoginRequest) (*models.LoginResponse, error) {
 	var userRow database.GetValidUserByLoginCredentialsRow
 	var session database.Session
+	var err error
 
 	helper, db, _ := database.NewDbHelperTransaction(a.dbctx)
-  defer helper.Rollback()
-
-	var err error
+  defer helper.RollbackOnError(err)
 
 	userRow, err = db.TXQueries.GetValidUserByLoginCredentials(db.CTX, database.GetValidUserByLoginCredentialsParams{
 		Username: request.Username,
@@ -417,7 +416,7 @@ func (a *authServiceImpl) PasswordResetBegin(request models.PasswordResetBeginRe
 	var err error
 
 	helper, db, err := database.NewDbHelperTransaction(a.dbctx)
-	defer helper.Rollback()
+	defer helper.RollbackOnError(err)
 
 	ctx := context.TODO()