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

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

Class Method Summary collapse

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Class Method Details

.autocorrect_incompatible_with ⇒ Object 



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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

rubocop:disable Metrics/AbcSize,Metrics/CyclomaticComplexity



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# File 'lib/rubocop/cop/style/negated_if_else_condition.rb', line 50

def on_if(node)
  return unless if_else?(node)
  return unless (condition = unwrap_begin_nodes(node.condition))
  return if double_negation?(condition) || !negated_condition?(condition)
  return unless condition.arguments.size < 2

  message = message(node)
  add_offense(node, message: message) 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_investigation ⇒ Object 



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

def on_new_investigation
  @corrected_nodes = nil
end