Commit b9fa17d8 authored by Robert Speicher's avatar Robert Speicher

Add AddColumnWithDefaultToLargeTable cop

parent 9c27c90b
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 AddColumnWithDefaultToLargeTable < RuboCop::Cop::Cop
include MigrationHelpers
MSG = 'Using `add_column_with_default` on the `%s` table will take a ' \
'long time to complete, and should be avoided unless absolutely ' \
'necessary'.freeze
LARGE_TABLES = %i[
events
issues
merge_requests
namespaces
notes
projects
routes
users
].freeze
def_node_matcher :add_column_with_default?, <<~PATTERN
(send nil :add_column_with_default $(sym ...) ...)
PATTERN
def on_send(node)
return unless in_migration?(node)
matched = add_column_with_default?(node)
return unless matched
table = matched.to_a.first
return unless LARGE_TABLES.include?(table)
add_offense(node, :expression, format(MSG, table))
end
end
end
end
end
require_relative 'cop/custom_error_class'
require_relative 'cop/gem_fetcher'
require_relative 'cop/migration/add_column'
require_relative 'cop/migration/add_column_with_default_to_large_table'
require_relative 'cop/migration/add_concurrent_foreign_key'
require_relative 'cop/migration/add_concurrent_index'
require_relative 'cop/migration/add_index'
......
require 'spec_helper'
require 'rubocop'
require 'rubocop/rspec/support'
require_relative '../../../../rubocop/cop/migration/add_column_with_default_to_large_table'
describe RuboCop::Cop::Migration::AddColumnWithDefaultToLargeTable do
include CopHelper
subject(:cop) { described_class.new }
context 'in migration' do
before do
allow(cop).to receive(:in_migration?).and_return(true)
end
described_class::LARGE_TABLES.each do |table|
it "registers an offense for the #{table} table" do
inspect_source(cop, "add_column_with_default :#{table}, :column, default: true")
aggregate_failures do
expect(cop.offenses.size).to eq(1)
expect(cop.offenses.map(&:line)).to eq([1])
end
end
end
it 'registers no offense for non-blacklisted tables' do
inspect_source(cop, "add_column_with_default :table, :column, default: true")
expect(cop.offenses).to be_empty
end
end
context 'outside of migration' do
it 'registers no offense' do
table = described_class::LARGE_TABLES.sample
inspect_source(cop, "add_column_with_default :#{table}, :column, default: true")
expect(cop.offenses).to be_empty
end
end
end
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