Class: RuboCop::Cop::Style::NegatedIfElseCondition

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RangeHelp
Defined in:
lib/rubocop/cop/style/negated_if_else_condition.rb

Overview

This cop checks for uses of `if-else` and ternary operators with a negated condition which can be simplified by inverting condition and swapping branches.

Examples:

# bad
if !x
  do_something
else
  do_something_else
end

# good
if x
  do_something_else
else
  do_something
end

# bad
!x ? do_something : do_something_else

# good
x ? do_something_else : do_something

Constant Summary collapse

MSG =
'Invert the negated condition and swap the %<type>s branches.'
NEGATED_EQUALITY_METHODS =
%i[!= !~].freeze

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Class Method Summary collapse

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#add_global_offense, #add_offense, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_other_file, #parse, #ready, #relevant_file?, 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?, #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

Class Method Details

.autocorrect_incompatible_withObject


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

def self.autocorrect_incompatible_with
  [Style::InverseMethods, Style::Not]
end

Instance Method Details

#double_negation?(node) ⇒ Object


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

def_node_matcher :double_negation?, '(send (send _ :!) :!)'

#on_if(node) ⇒ Object


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# File 'lib/rubocop/cop/style/negated_if_else_condition.rb', line 49

def on_if(node)
  return unless if_else?(node)

  condition = node.condition
  return if double_negation?(condition) || !negated_condition?(condition)

  type = node.ternary? ? 'ternary' : 'if-else'
  add_offense(node, message: format(MSG, type: type)) do |corrector|
    unless corrected_ancestor?(node)
      correct_negated_condition(corrector, condition)
      swap_branches(corrector, node)

      @corrected_nodes ||= Set.new.compare_by_identity
      @corrected_nodes.add(node)
    end
  end
end

#on_new_investigationObject


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# File 'lib/rubocop/cop/style/negated_if_else_condition.rb', line 45

def on_new_investigation
  @corrected_nodes = nil
end