def upgrade(self, storage):
config = load_config_from_storage(storage)
if config["format"] == self.target:
return False
if config["format"] not in self.upgraders:
raise UserError("cannot migrate from version " + config["format"] + " to version " + self.target)
while config["format"] != self.target:
self.upgraders[config["format"]](storage, config)
save_config_to_storage(storage, config)
return True
def storage_with_config(config):
storage = MemStorage("testing")
save_config_to_storage(storage, config)
return storage
