Class: OnlineMigrations::BackgroundMigrations::MigrationStatusValidator

Inherits:
ActiveModel::Validator
  • Object
show all
Defined in:
lib/online_migrations/background_migrations/migration_status_validator.rb

Constant Summary collapse

VALID_STATUS_TRANSITIONS = 
{
  # enqueued -> running occurs when the migration starts performing.
  # enqueued -> paused occurs when the migration is paused before starting.
  "enqueued" => ["running", "paused", "cancelled"],
  # running -> paused occurs when a user pauses the migration as
  #   it's performing.
  # running -> finishing occurs when a user manually finishes the migration.
  # running -> succeeded occurs when the migration completes successfully.
  # running -> failed occurs when the migration raises an exception when running.
  "running" => [
    "paused",
    "finishing",
    "succeeded",
    "failed",
    "cancelled",
  ],
  # finishing -> succeeded occurs when the migration completes successfully.
  # finishing -> failed occurs when the migration raises an exception when running.
  "finishing" => ["succeeded", "failed", "cancelled"],
  # paused -> running occurs when the migration is resumed after being paused.
  "paused" => ["running", "cancelled"],
  # failed -> enqueued occurs when the failed migration jobs are retried after being failed.
  # failed -> running occurs when the failed migration is retried.
  "failed" => ["enqueued", "running", "cancelled"],
}

Instance Method Summary collapse

Instance Method Details

#validate(record) ⇒ Object 



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# File 'lib/online_migrations/background_migrations/migration_status_validator.rb', line 33

def validate(record)
  return if !record.status_changed?

  previous_status, new_status = record.status_change
  valid_new_statuses = VALID_STATUS_TRANSITIONS.fetch(previous_status, [])

  if !valid_new_statuses.include?(new_status)
    record.errors.add(
      :status,
      "cannot transition background migration from status #{previous_status} to #{new_status}"
    )
  end
end