Pry `db-exec` command

.pryrc

if defined?(ActiveRecord::Base)
  Pry::Commands.create_command 'db-exec' do
    description 'Run SQL statement with ActiveRecord::Base.connection'

    banner <<-BANNER
      Usage: db-exec [ > OUTPUT ] STATEMENT
             db-exec [ > OUTPUT ] < INPUT
             db-exec < INPUT > OUTPUT

      Examples:

      db-exec SELECT NOW()            execute any SQL statement
      db-exec -- SELECT NOW() -h      add -- to avoid option parsing
      db-exec \#{User.all.to_sql}      you can use interpolation
      db-exec < in.sql                execute content read from file
      db-exec < in.sql > out.txt      and write result to another file
    BANNER

    def options(opt)
      opt.on '-t', '--to=', 'Assign result object to specific local variable.'
    end

    def process
      var  = opts.to? ? opts[:to] : nil
      pipe = {}
      while args.length > 0 && args[0].to_s.presence_in(%w[> <])
        raise Pry::CommandError, "Missing pipe argument after '#{args[0]}'" if args[1].blank?
        pipe[args[0]] = args[1]
        args.shift
        args.shift
      end

      stmt = if pipe.key?('<')
               IO.read(pipe['<'])
             else
              args.join(' ').strip
             end

      result = ActiveRecord::Base.connection.execute(stmt)
      raise Pry::CommandError, "Execute error #{result.error_message}" if result.error_message.present?

      # NOTE: require customized ai (awesome_inspect) for table output
      if pipe.key?('>')
        IO.write(pipe['>'], result.ai(table: true, plain: true, multibyte: true, max_width: 0))
        output.puts "result written to #{pipe['>']}"
      else
        output.puts result.ai(table: true)
      end

      if var.present?
        target.local_variable_set(var.to_sym, result)
      end
    end
  end
end