Class: RuboCop::Cop::Style::TrailingUnderscoreVariable

Inherits:
Cop
  • Object
show all
Includes:
RuboCop::Cop::SurroundingSpace
Defined in:
lib/rubocop/cop/style/trailing_underscore_variable.rb

Overview

This cop checks for extra underscores in variable assignment.

Examples:

# bad
a, b, _ = foo()
a, b, _, = foo()
a, _, _ = foo()
a, _, _, = foo()

#good
a, b, = foo()
a, = foo()
*a, b, _ = foo()  => We need to know to not include 2 variables in a
a, *b, _ = foo()  => The correction `a, *b, = foo()` is a syntax error

Constant Summary collapse

MSG = 
'Do not use trailing `_`s in parallel assignment.'.freeze
UNDERSCORE = 
'_'.freeze

Constants included from Util

Util::ASGN_NODES, Util::BASIC_LITERALS, Util::EQUALS_ASGN_NODES, Util::LITERALS, 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 included from RuboCop::Cop::SurroundingSpace

#index_of_first_token, #index_of_last_token, #space_between?, #token_table

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, qualified_cop_name, rails?, #reference_url, #relevant_file?, #style_guide_url

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search

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, command?, comment_line?, const_name, directions, first_part_of_call_chain, lambda?, lambda_or_proc?, line_range, move_pos, 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

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/style/trailing_underscore_variable.rb', line 40

def autocorrect(node)
  left, right = *node
  variables = *left
  first_offense = find_first_offense(variables)

  end_position =
    if first_offense.loc.expression == variables.first.loc.expression
      right.loc.expression.begin_pos
    else
      node.loc.operator.begin_pos
    end

  range =
    Parser::Source::Range.new(node.loc.expression.source_buffer,
                              first_offense.loc.expression.begin_pos,
                              end_position)

  ->(corrector) { corrector.remove(range) unless range.nil? }
end

#on_masgn(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/trailing_underscore_variable.rb', line 26

def on_masgn(node)
  left, = *node
  variables = *left
  first_offense = find_first_offense(variables)

  return if first_offense.nil?

  range =
    Parser::Source::Range.new(node.loc.expression.source_buffer,
                              first_offense.loc.expression.begin_pos,
                              variables.last.loc.expression.end_pos)
  add_offense(node, range)
end