Class: RuboCop::Cop::Rails::ReversibleMigration

Inherits:

Cop

• Object
• Cop
• RuboCop::Cop::Rails::ReversibleMigration

Defined in:

lib/rubocop/cop/rails/reversible_migration.rb

Overview

This cop checks whether the change method of the migration file is reversible.

Examples:

# bad
def change
  change_table :users do |t|
    t.remove :name
  end
end

# good
def change
  create_table :users do |t|
    t.string :name
  end
end

# good
def change
  reversible do |dir|
    change_table :users do |t|
      dir.up do
        t.column :name, :string
      end

      dir.down do
        t.remove :name
      end
    end
  end
end

# drop_table

# bad
def change
  drop_table :users
end

# good
def change
  drop_table :users do |t|
    t.string :name
  end
end

# change_column_default

# bad
def change
  change_column_default(:suppliers, :qualification, 'new')
end

# good
def change
  change_column_default(:posts, :state, from: nil, to: "draft")
end

# remove_column

# bad
def change
  remove_column(:suppliers, :qualification)
end

# good
def change
  remove_column(:suppliers, :qualification, :string)
end

# remove_foreign_key

# bad
def change
  remove_foreign_key :accounts, column: :owner_id
end

# good
def change
  remove_foreign_key :accounts, :branches
end

# change_table

# bad
def change
  change_table :users do |t|
    t.remove :name
    t.change_default :authorized, 1
    t.change :price, :string
  end
end

# good
def change
  change_table :users do |t|
    t.string :name
  end
end

# good
def change
  reversible do |dir|
    change_table :users do |t|
      dir.up do
        t.change :price, :string
      end

      dir.down do
        t.change :price, :integer
      end
    end
  end
end

See Also:

• https://api.rubyonrails.org/classes/ActiveRecord/Migration/CommandRecorder.html

Constant Summary

MSG =

'%<action>s is not reversible.'

IRREVERSIBLE_CHANGE_TABLE_CALLS =

%i[
  change change_default remove
].freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary

• #on_block(node) ⇒ Object
• #on_send(node) ⇒ Object

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, #correct, department, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, chdir, hidden_dir?, hidden_file_in_not_hidden_dir?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

This class inherits a constructor from RuboCop::Cop::Cop

Instance Method Details

#on_block(node) ⇒ Object

# File 'lib/rubocop/cop/rails/reversible_migration.rb', line 169

def on_block(node)
  return unless within_change_method?(node)
  return if within_reversible_or_up_only_block?(node)
  return if node.body.nil?

  check_change_table_node(node.send_node, node.body)
end

#on_send(node) ⇒ Object

# File 'lib/rubocop/cop/rails/reversible_migration.rb', line 158

def on_send(node)
  return unless within_change_method?(node)
  return if within_reversible_or_up_only_block?(node)

  check_irreversible_schema_statement_node(node)
  check_drop_table_node(node)
  check_change_column_default_node(node)
  check_remove_column_node(node)
  check_remove_foreign_key_node(node)
end