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

Inherits:
Cop
  • Object
show all
Includes:
RangeHelp, 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

AllowNamedUnderscoreVariables: true (default)

# good
a, b, _something = foo()

AllowNamedUnderscoreVariables: false

# bad
a, b, _something = foo()

Constant Summary collapse

MSG = 
'Do not use trailing `_`s in parallel assignment. ' \
'Prefer `%<code>s`.'
UNDERSCORE = 
'_'

Constants included from RuboCop::Cop::SurroundingSpace

RuboCop::Cop::SurroundingSpace::NO_SPACE_COMMAND, RuboCop::Cop::SurroundingSpace::SINGLE_SPACE_REGEXP, RuboCop::Cop::SurroundingSpace::SPACE_COMMAND

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, #disable_uncorrectable, #duplicate_location?, #excluded_file?, #external_dependency_checksum, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, #parse, qualified_cop_name, #reason_to_not_correct, #relevant_file?, #target_rails_version, #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?, #correctable?, #disable_offense, #disable_uncorrectable?, #safe_autocorrect?, #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, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, chdir, 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/style/trailing_underscore_variable.rb', line 53

def autocorrect(node)
  ranges = unneeded_ranges(node)

  lambda do |corrector|
    ranges.each { |range| corrector.remove(range) if range }
  end
end

#on_masgn(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/trailing_underscore_variable.rb', line 39

def on_masgn(node)
  ranges = unneeded_ranges(node)

  ranges.each do |range|
    good_code = node.source
    offset = range.begin_pos - node.source_range.begin_pos
    good_code[offset, range.size] = ''

    add_offense(node,
                location: range,
                message: format(MSG, code: good_code))
  end
end