Class: RuboCop::Cop::Performance::Casecmp

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/performance/casecmp.rb

Overview

This cop identifies places where a case-insensitive string comparison can better be implemented using `casecmp`.

Examples:

# bad
str.downcase == 'abc'
str.upcase.eql? 'ABC'
'abc' == str.downcase
'ABC'.eql? str.upcase
str.downcase == str.downcase

# good
str.casecmp('ABC').zero?
'abc'.casecmp(str).zero?

Constant Summary collapse

MSG =
'Use `%<good>s` instead of `%<bad>s`.'.freeze
CASE_METHODS =
%i[downcase upcase].freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

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 NodePattern::Macros

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

Methods included from AST::Sexp

#s

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

Methods included from PathUtil

absolute?, 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

#autocorrect(node) ⇒ Object



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# File 'lib/rubocop/cop/performance/casecmp.rb', line 58

def autocorrect(node)
  return unless (parts = take_method_apart(node))

  receiver, method, arg, variable = parts

  correction(node, receiver, method, arg, variable)
end

#on_send(node) ⇒ Object



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# File 'lib/rubocop/cop/performance/casecmp.rb', line 45

def on_send(node)
  return unless downcase_eq(node) || eq_downcase(node)
  return unless (parts = take_method_apart(node))

  _, _, arg, variable = parts
  good_method = build_good_method(arg, variable)

  add_offense(
    node,
    message: format(MSG, good: good_method, bad: node.source)
  )
end