Class: RuboCop::Cop::Performance::HashEachMethods

Inherits:
Cop
  • Object
show all
Includes:
Lint::UnusedArgument
Defined in:
lib/rubocop/cop/performance/hash_each_methods.rb

Overview

This cop checks for uses of ‘each_key` & `each_value` Hash methods.

Examples:

# bad
hash.keys.each { |k| p k }
hash.values.each { |v| p v }
hash.each { |k, _v| p k }
hash.each { |_k, v| p v }

# good
hash.each_key { |k| p k }
hash.each_value { |v| p v }

Constant Summary collapse

MSG = 
'Use `%s` instead of `%s`.'.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 Lint::UnusedArgument

#after_leaving_scope, #join_force?

Methods inherited from Cop

#add_offense, all, 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_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?, block_length, comment_line?, compatible_external_encoding_for?, directions, double_quotes_acceptable?, double_quotes_required?, effective_column, ends_its_line?, escape_string, first_part_of_call_chain, hard_to_type?, interpret_string_escapes, line_distance, line_range, move_pos, needs_escaping?, numeric_range_size, on_node, operator?, parentheses?, parenthesized_call?, preceed?, range_between, range_with_surrounding_comma, range_with_surrounding_space, same_line?, source_range, strip_quotes, stripped_source_upto, to_string_literal, to_supported_styles, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, 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/hash_each_methods.rb', line 51

def autocorrect(node)
  receiver, _second_method = *node
  caller, first_method = *receiver
  lambda do |corrector|
    if first_method == :hash
      method = @args.values.first ? :key : :value
      new_source = receiver.source + ".each_#{method}"
      corrector.replace(node.loc.expression, new_source)
      correct_args(node, corrector)
    else
      new_source = caller.source + ".each_#{first_method[0..-2]}"
      corrector.replace(node.loc.expression, new_source)
    end
  end
end

#check_argument(variable) ⇒ Object 



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# File 'lib/rubocop/cop/performance/hash_each_methods.rb', line 46

def check_argument(variable)
  return unless variable.block_argument?
  (@args ||= {})[variable.name] = variable.used?
end

#on_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/performance/hash_each_methods.rb', line 31

def on_block(node)
  plain_each(node) do |target, k, v|
    return if @args[k] && @args[v]
    used = @args[k] ? :key : :value
    add_offense(target, range(target), format(message,
                                              "each_#{used}",
                                              :each))
  end
  kv_each(node) do |target, method|
    add_offense(target, range(target), format(message,
                                              "each_#{method[0..-2]}",
                                              "#{method}.each"))
  end
end