module Opal::Nodes::Helpers

def js_falsy(sexp)
  if sexp.type == :call
    mid = sexp[2]
    if mid == :block_given?
      scope.uses_block!
      return "#{scope.block_name} === nil"
    end
  end
  with_temp do |tmp|
    [fragment("((#{tmp} = "), expr(sexp), fragment(") === nil || (#{tmp}._isBoolean && #{tmp} == false))")]
  end
end