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

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RangeHelp, RuboCop::Cop::SurroundingSpace
Defined in:
lib/rubocop/cop/style/trailing_underscore_variable.rb

Overview

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 inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Method Details

#on_masgn(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/trailing_underscore_variable.rb', line 41

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(range, message: format(MSG, code: good_code)) do |corrector|
      corrector.remove(range)
    end
  end
end