def _reverse_migration_impl(
self, migration_key: MigrationKey, *, dry_run: bool = False
) -> None:
migration_id = migration_key.migration_id
context = Context(
migration_id, logger, partial(self._update_migration_status, migration_key),
)
migration = get_group_loader(migration_key.group).load_migration(migration_id)
migration.backwards(context, dry_run)
def _run_migration_impl(
self, migration_key: MigrationKey, *, force: bool = False, dry_run: bool = False
) -> None:
migration_id = migration_key.migration_id
context = Context(
migration_id, logger, partial(self._update_migration_status, migration_key),
)
migration = get_group_loader(migration_key.group).load_migration(migration_id)
if migration.blocking and not dry_run and not force:
raise MigrationError("Blocking migrations must be run with force")
migration.forwards(context, dry_run)
def reverse_migration(
self,
migration_key: MigrationKey,
*,
force: bool = False,
fake: bool = False,
) -> None:
"""
Reverses a migration.
"""
migration_group, migration_id = migration_key
group_migrations = get_group_loader(migration_group).get_migrations()
if migration_id not in group_migrations:
raise MigrationError("Invalid migration")
migration_status = self._get_migration_status()
def get_status(migration_key: MigrationKey) -> Status:
return migration_status.get(migration_key, Status.NOT_STARTED)
if get_status(migration_key) == Status.NOT_STARTED:
raise MigrationError(
"You cannot reverse a migration that has not been run")
if get_status(
migration_key) == Status.COMPLETED and not force and not fake:
raise MigrationError(
"You must use force to revert an already completed migration")
for m in group_migrations[group_migrations.index(migration_id) + 1:]:
if get_status(MigrationKey(migration_group,
m)) != Status.NOT_STARTED:
raise MigrationError(
"Subsequent migrations must be reversed first")
if fake:
self._update_migration_status(migration_key, Status.NOT_STARTED)
else:
context = Context(
migration_id,
logger,
partial(self._update_migration_status, migration_key),
)
migration = get_group_loader(
migration_key.group).load_migration(migration_id)
migration.backwards(context)