If it didn't abort, it succeeded. Take a look at the code:
# desc "Raises an error if there are pending migrations"
task :abort_if_pending_migrations => :environment do
pending_migrations = ActiveRecord::Migrator.open(ActiveRecord::Migrator.migrations_paths).pending_migrations
if pending_migrations.any?
puts "You have #{pending_migrations.size} pending #{pending_migrations.size > 1 ? 'migrations:' : 'migration:'}"
pending_migrations.each do |pending_migration|
puts ' %4d %s' % [pending_migration.version, pending_migration.name]
end
abort %{Run `rake db:migrate` to update your database then try again.}
end
end
It literally does nothing if there aren't any pending migrations.