Generate fixtures from db. Readable by rake db:fixtures:load

db_fixtures_export.rake

# https://gist.github.com/kuboon/55d4d8e862362d30456e7aa7cd6c9cf5

namespace 'db:fixtures' do
  desc "generate fixtures from the current database"

  task :export => :environment do
    Rails.application.eager_load!
    models = defined?(ApplicationRecord) ? ApplicationRecord.descendants : ActiveRecord::Base.descendants
    models.each do |model|
      puts "exporting: #{model}"

      # e.g. Namespace::Class -> test/fixtures/namespace/class.yml
      model_name = model.name
      model_name = model_name.pluralize if model.pluralize_table_names?
      model_name = model_name.underscore

      filepath = Rails.root.join('test/fixtures', "#{model_name}.yml")
      FileUtils.mkdir_p filepath.dirname

      filepath.open('w') do |file|
        hash = {}
        model.find_each do |r|
          key = r.try(:name) || "#{filepath.basename('.*')}_#{r.id}"
          hash[key] = r.attributes.except(:password_digest)
        end
        file.write "# Read about fixtures at http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html\n\n"
        file.write hash.to_yaml
      end
    end
  end
end