fix(model): centralize row locking in transactional flows

model/locking_test.go

@@ -0,0 +1,38 @@
+package model
+
+import (
+	"testing"
+
+	"github.com/QuantumNous/new-api/common"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+	"gorm.io/gorm/utils/tests"
+)
+
+// lockForUpdate must emit FOR UPDATE on databases that support it and skip
+// it on SQLite, where the syntax does not exist.
+//
+// The dummy dialector is used because SQLite drivers strip locking clauses
+// from the generated SQL, which would mask what the helper itself does.
+func TestLockForUpdateEmitsRowLock(t *testing.T) {
+	dummyDB, err := gorm.Open(tests.DummyDialector{}, &gorm.Config{DryRun: true})
+	require.NoError(t, err)
+	buildSQL := func() string {
+		var rows []Redemption
+		return lockForUpdate(dummyDB).Where("id = ?", 1).Find(&rows).Statement.SQL.String()
+	}
+
+	t.Cleanup(func() {
+		common.SetDatabaseTypes(common.DatabaseTypeSQLite, common.DatabaseTypeSQLite)
+	})
+
+	common.SetDatabaseTypes(common.DatabaseTypeMySQL, common.DatabaseTypeSQLite)
+	assert.Contains(t, buildSQL(), "FOR UPDATE")
+
+	common.SetDatabaseTypes(common.DatabaseTypePostgreSQL, common.DatabaseTypeSQLite)
+	assert.Contains(t, buildSQL(), "FOR UPDATE")
+
+	common.SetDatabaseTypes(common.DatabaseTypeSQLite, common.DatabaseTypeSQLite)
+	assert.NotContains(t, buildSQL(), "FOR UPDATE")
+}