require_relative '../../migration_helpers' module RuboCop module Cop module Migration # This cop checks for `add_column_with_default` on a table that's been # explicitly blacklisted because of its size. # # Even though this helper performs the update in batches to avoid # downtime, using it with tables with millions of rows still causes a # significant delay in the deploy process and is best avoided. # # See https://gitlab.com/gitlab-com/infrastructure/issues/1602 for more # information. class UpdateLargeTable < RuboCop::Cop::Cop include MigrationHelpers MSG = 'Using `%s` on the `%s` table will take a long time to ' \ 'complete, and should be avoided unless absolutely ' \ 'necessary'.freeze LARGE_TABLES = %i[ ci_build_trace_sections ci_builds ci_job_artifacts ci_pipelines ci_stages events issues merge_request_diff_commits merge_request_diff_files merge_request_diffs merge_requests namespaces notes projects routes users ].freeze BATCH_UPDATE_METHODS = %w[ :add_column_with_default :change_column_type_concurrently :rename_column_concurrently :update_column_in_batches ].join(' ').freeze def_node_matcher :batch_update?, <<~PATTERN (send nil? ${#{BATCH_UPDATE_METHODS}} $(sym ...) ...) PATTERN def on_send(node) return unless in_migration?(node) matches = batch_update?(node) return unless matches update_method = matches.first table = matches.last.to_a.first return unless LARGE_TABLES.include?(table) add_offense(node, location: :expression, message: format(MSG, update_method, table)) end end end end end