class RuboCop::Cop::Style::GuardClause

def assigned_lvar_used_in_if_branch?(node)
  return false unless (if_branch = node.if_branch)
  assigned_lvars_in_condition = node.condition.each_descendant(:lvasgn).map do |lvasgn|
    lvar_name, = *lvasgn
    lvar_name.to_s
  end
  used_lvars_in_branch = if_branch.each_descendant(:lvar).map(&:source) || []
  (assigned_lvars_in_condition & used_lvars_in_branch).any?
end