class RuboCop::Cop::Performance::RedundantEqualityComparisonBlock

This cop checks for uses `Enumerable#all?`, `Enumerable#any?`, `Enumerable#one?`, and `Enumerable#none?` are compared with `===` or similar methods in block.

By default, `Object#===` behaves the same as `Object#==`, but this behavior is appropriately overridden in subclass. For example, `Range#===` returns `true` when argument is within the range. Therefore, It is marked as unsafe by default because `===` and `==` do not always behave the same.

@example

# bad
items.all? { |item| pattern === item }
items.all? { |item| item == other }
items.all? { |item| item.is_a?(Klass) }
items.all? { |item| item.kind_of?(Klass) }

# good
items.all?(pattern)

Constants

COMPARISON_METHODS
IS_A_METHODS
MSG
TARGET_METHODS

Public Instance Methods

on_block(node) click to toggle source
# File lib/rubocop/cop/performance/redundant_equality_comparison_block.rb, line 37
def on_block(node)
  return unless TARGET_METHODS.include?(node.method_name)
  return unless one_block_argument?(node.arguments)

  block_argument = node.arguments.first
  block_body = node.body
  return unless use_equality_comparison_block?(block_body)
  return if same_block_argument_and_is_a_argument?(block_body, block_argument)
  return unless (new_argument = new_argument(block_argument, block_body))

  range = offense_range(node)
  prefer = "#{node.method_name}(#{new_argument})"

  add_offense(range, message: format(MSG, prefer: prefer)) do |corrector|
    corrector.replace(range, prefer)
  end
end

Private Instance Methods

new_argument(block_argument, block_body) click to toggle source
# File lib/rubocop/cop/performance/redundant_equality_comparison_block.rb, line 75
def new_argument(block_argument, block_body)
  if block_argument.source == block_body.receiver.source
    rhs = block_body.first_argument
    return if use_block_argument_in_method_argument_of_operand?(block_argument, rhs)

    rhs.source
  elsif block_argument.source == block_body.first_argument.source
    lhs = block_body.receiver
    return if use_block_argument_in_method_argument_of_operand?(block_argument, lhs)

    lhs.source
  end
end
offense_range(node) click to toggle source
# File lib/rubocop/cop/performance/redundant_equality_comparison_block.rb, line 98
def offense_range(node)
  node.send_node.loc.selector.join(node.source_range.end)
end
one_block_argument?(block_arguments) click to toggle source
# File lib/rubocop/cop/performance/redundant_equality_comparison_block.rb, line 57
def one_block_argument?(block_arguments)
  block_arguments.one? && !block_arguments.source.include?(',')
end
same_block_argument_and_is_a_argument?(block_body, block_argument) click to toggle source
# File lib/rubocop/cop/performance/redundant_equality_comparison_block.rb, line 65
def same_block_argument_and_is_a_argument?(block_body, block_argument)
  if block_body.method?(:===)
    block_argument.source != block_body.children[2].source
  elsif IS_A_METHODS.include?(block_body.method_name)
    block_argument.source == block_body.first_argument.source
  else
    false
  end
end
use_block_argument_in_method_argument_of_operand?(block_argument, operand) click to toggle source
# File lib/rubocop/cop/performance/redundant_equality_comparison_block.rb, line 89
def use_block_argument_in_method_argument_of_operand?(block_argument, operand)
  return false unless operand.send_type?

  arguments = operand.arguments
  arguments.inject(arguments.map(&:source)) do |operand_sources, argument|
    operand_sources + argument.each_descendant(:lvar).map(&:source)
  end.any?(block_argument.source)
end
use_equality_comparison_block?(block_body) click to toggle source
# File lib/rubocop/cop/performance/redundant_equality_comparison_block.rb, line 61
def use_equality_comparison_block?(block_body)
  block_body.send_type? && COMPARISON_METHODS.include?(block_body.method_name)
end