Class: RuboCop::Cop::Style::Alias

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/alias.rb

Overview

The purpose of the this cop is advise the use of alias_method over the alias keyword whenever possible.

Constant Summary collapse

MSG = 
'Use `alias_method` instead of `alias`.'

Constants included from Util

Util::ASGN_NODES, Util::EQUALS_ASGN_NODES, Util::OPERATOR_METHODS, Util::PROC_NEW_NODE, Util::SHORTHAND_ASGN_NODES

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, #autocorrect?, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, cop_name_with_namespace, cop_type, #debug?, #display_cop_names?, inherited, #initialize, #join_force?, lint?, #message, non_rails, qualified_cop_name, rails?, #relevant_file?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, block_length, command?, comment_line?, const_name, first_part_of_call_chain, lambda?, lambda_or_proc?, line_range, numeric_range_size, on_node, operator?, parentheses?, proc?, range_with_surrounding_comma, range_with_surrounding_space, source_range, strip_quotes, within_node?

Methods included from PathUtil

issue_deprecation_warning, match_path?, relative_path

Constructor Details

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

Instance Method Details

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/alias.rb', line 33

def autocorrect(node)
  @corrections << lambda do |corrector|
    # replace alias with alias_method
    corrector.replace(node.loc.keyword, 'alias_method')
    # insert a comma
    new, old = *node
    corrector.insert_after(new.loc.expression, ',')
    # convert bareword arguments to symbols
    corrector.replace(new.loc.expression, ":#{new.children.first}")
    corrector.replace(old.loc.expression, ":#{old.children.first}")
  end
end

#on_alias(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/alias.rb', line 22

def on_alias(node)
  return if ignored_node?(node)

  # alias_method can't be used with global variables
  new, old = *node

  return if new.type == :gvar && old.type == :gvar

  add_offense(node, :keyword)
end

#on_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/alias.rb', line 11

def on_block(node)
  method, _args, body = *node
  _receiver, method_name = *method

  # using alias is the only option in certain scenarios
  # in such scenarios we don't want to report an offense
  return unless method_name == :instance_exec

  body.each_node(:alias) { |n| ignore_node(n) }
end