refac: migration crash, real-database tests, site deleted during create, ruels out of the repo, lists

internal/infrastructure/persistence/database/mysql.go

@@ -28,6 +28,8 @@ const (
 	mysqlLockWaitTimeout = 1205
 	mysqlDeadlock        = 1213
 	mysqlSnapshotChanged = 1020
+	mysqlDuplicateEntry  = 1062
+	mysqlDuplicateKeyed  = 1586
 )
 
 type mysqlDriver struct{}
@@ -94,6 +96,16 @@ func tableOptionsFor(db *gorm.DB) *gorm.DB {
 var mysqlContentionCodes = []uint16{mysqlLockNowait, mysqlLockWaitTimeout, mysqlDeadlock, mysqlSnapshotChanged}
 
 func (mysqlDriver) IsLockContention(err error) bool {
+	return hasMySQLCode(err, mysqlContentionCodes)
+}
+
+var mysqlUniqueViolationCodes = []uint16{mysqlDuplicateEntry, mysqlDuplicateKeyed}
+
+func (mysqlDriver) IsUniqueViolation(err error) bool {
+	return hasMySQLCode(err, mysqlUniqueViolationCodes)
+}
+
+func hasMySQLCode(err error, codes []uint16) bool {
 	var failure *mysqldriver.MySQLError
-	return errors.As(err, &failure) && slices.Contains(mysqlContentionCodes, failure.Number)
+	return errors.As(err, &failure) && slices.Contains(codes, failure.Number)
 }