Class: RuboCop::Cop::Rails::InverseOf

Inherits:
Cop
  • Object
show all
Extended by:
TargetRailsVersion
Defined in:
lib/rubocop/cop/rails/inverse_of.rb

Overview

This cop looks for has_(one|many) and belongs_to associations where ActiveRecord can’t automatically determine the inverse association because of a scope or the options used. This can result in unnecessary queries in some circumstances. ‘:inverse_of` must be manually specified for associations to work in both ways, or set to `false` to opt-out.

Examples:

# bad
class Blog < ApplicationRecord
  has_many :recent_posts, -> { order(published_at: :desc) }
end

# good
class Blog < ApplicationRecord
  has_many(:recent_posts,
    -> { order(published_at: :desc) },
    inverse_of: :blog
  )
end

See Also:

Constant Summary collapse

MSG = 
'Specify an `:inverse_of` option.'.freeze

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::CONDITIONAL_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::LOGICAL_OPERATOR_NODES, Util::MODIFIER_NODES, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods included from TargetRailsVersion

minimum_target_rails_version, support_target_rails_version?

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?, effective_column, ends_its_line?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, operator?, parentheses?, parenthesized_call?, precede?, range_between, range_by_whole_lines, range_with_surrounding_comma, range_with_surrounding_space, same_line?, source_range, strip_quotes, stripped_source_upto, symbol_without_quote?, to_string_literal, to_supported_styles, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/rails/inverse_of.rb', line 63

def on_send(node)
  arguments = association_arguments(node)
  return unless arguments

  options = arguments.flat_map { |arg| options_from_argument(arg) }
  return unless scope?(arguments) ||
                options_requiring_inverse_of?(options)

  return if options_contain_inverse_of?(options)
  add_offense(node, location: :selector)
end

#options_contain_inverse_of?(options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/rails/inverse_of.rb', line 90

def options_contain_inverse_of?(options)
  options.any? { |opt| inverse_of_option?(opt) }
end

#options_requiring_inverse_of?(options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/rails/inverse_of.rb', line 79

def options_requiring_inverse_of?(options)
  required = options.any? do |opt|
    conditions_option?(opt) ||
      through_option?(opt) ||
      foreign_key_option?(opt)
  end

  return required if target_rails_version >= 5.2
  required || options.any? { |opt| polymorphic_option?(opt) }
end

#scope?(arguments) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/rails/inverse_of.rb', line 75

def scope?(arguments)
  arguments.any?(&:block_type?)
end