reversible_data_migrations

🛠️ Implement Reversible Data Migrations

For data migrations that should be reversible, use the reversible helper to define up and down data changes. This ensures that rolling back also reverts data transformations predictably. It’s ideal for cleaning or migrating columns without leaving stale data.

class NormalizeUserNames < ActiveRecord::Migration[6.1]
  def change
    reversible do |dir|
      dir.up do
        User.find_each { |u| u.update_columns(name: u.name.strip.titleize) }
      end

      dir.down do
        User.find_each { |u| u.update_columns(name: u.name.downcase) }
      end
    end
  end
end