class RuboCop::Cop::Performance::BlockGivenWithExplicitBlock

This cop identifies unnecessary use of a `block_given?` where explicit check of block argument would suffice.

@example

# bad
def method(&block)
  do_something if block_given?
end

# good
def method(&block)
  do_something if block
end

# good - block is reassigned
def method(&block)
  block ||= -> { do_something }
  warn "Using default ..." unless block_given?
  # ...
end

Constants

MSG
RESTRICT_ON_SEND

Public Instance Methods

on_send(node) click to toggle source
# File lib/rubocop/cop/performance/block_given_with_explicit_block.rb, line 35
def on_send(node)
  def_node = node.each_ancestor(:def, :defs).first
  return unless def_node

  block_arg = def_node.arguments.find(&:blockarg_type?)
  return unless block_arg

  block_arg_name = block_arg.loc.name.source.to_sym
  return if reassigns_block_arg?(def_node, block_arg_name)

  add_offense(node) do |corrector|
    corrector.replace(node, block_arg_name)
  end
end