module RuboCop::Cop::IfThenElse

def check(node)
  # We won't check modifier or ternary conditionals.
  return unless node.loc.expression.source =~ /\A(if|unless)\b/
  return unless offending_line(node)
  add_offense(node, :expression, error_message(node))
end

def on_if(node)
  check(node)
end

def on_unless(node)
  check(node)
end