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
'abc'.downcase == 'ABC'
'abc'.upcase.eql? 'ABC'

@good
'abc'.casecmp('ABC')

Constant Summary collapse

MSG = 
'Use `casecmp` instead of `%s %s`.'.freeze

Constants included from Util

Util::ASGN_NODES, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES, Util::STRING_ESCAPES, Util::STRING_ESCAPE_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_type, #correct, #debug?, #details, #display_cop_names?, #display_style_guide?, #excluded_file?, #extra_details?, inherited, #initialize, #join_force?, lint?, match?, #message, non_rails, #parse, qualified_cop_name, #reference_url, #relevant_file?, #style_guide_url, #target_ruby_version

Methods included from Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search_body

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?, block_length, comment_line?, directions, double_quotes_acceptable?, double_quotes_required?, ends_its_line?, first_part_of_call_chain, interpret_string_escapes, line_range, move_pos, numeric_range_size, on_node, operator?, parentheses?, range_with_surrounding_comma, range_with_surrounding_space, source_range, strip_quotes, to_string_literal, to_symbol_literal, within_node?

Methods included from PathUtil

hidden?, 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/performance/casecmp.rb', line 31

def autocorrect(node)
  receiver, _method, arg = *node
  range = Parser::Source::Range.new(node.source_range.source_buffer,
                                    receiver.loc.selector.begin_pos,
                                    arg.loc.begin.begin_pos)

  lambda do |corrector|
    # we want resulting call to be parenthesized
    # if arg already includes one or more sets of parens, don't add more
    # or if method call already used parens, again, don't add more
    if arg.loc.begin.source == '('
      corrector.replace(range, 'casecmp')
    elsif range.source =~ /\(/
      corrector.replace(range, 'casecmp(')
    else
      corrector.replace(range, 'casecmp(')
      corrector.insert_after(arg.source_range, ')')
    end
  end
end

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/performance/casecmp.rb', line 24

def on_send(node)
  downcase_eq(node) do |send_downcase, case_method, eq_method|
    range = node.loc.selector.join(send_downcase.loc.selector)
    add_offense(node, range, format(MSG, case_method, eq_method))
  end
end