NRepl for Ruby: simple nrepl client for Ruby 2+

nrepl.rb

require 'socket'
require 'bencode'
require 'securerandom'

module Loader
  class NRepl
    def self.connect(server, port)
      new(server, port)
    end

    def initialize(server, port)
      @port = port
      @server = server
      @conn = TCPSocket.new server, port
      @parser = BEncode::Parser.new(@conn)

      @session = op(:clone).select { |s| s['new-session'] }.first['new-session']
    end

    def send message
      msg = message.dup
      msg['id'] ||= SecureRandom.uuid
      @conn.write(msg.bencode)
      msg['id']
    end

    def recv message_id
      responses = []
      responses << @parser.parse! until !responses.empty? && responses.last.fetch("status", []).include?("done")
      responses
    end

    def op(name, opts = {})
      opts.keys.each do |key|
        opts[key.to_s] = opts.delete(key)
      end

      opts['op'] = name.to_s

      recv(send(opts))
    end

    def list_sessions
      op(:'ls-sessions', session: @session).map { |s| s['sessions'] }.first
    end

    def describe
      op(:describe, session: @session)
    end

    def load_file(file)
      op(:'load-file', file: file, session: @session)
    end

    def close_session(s)
      return if s.to_s == @session
      op(:close, session: s)
    end

    def eval code
      op(:eval, code: code, session: @session).select { |s| s['value'] }
    end

    def value code
      retval = op(:eval, code: code, session: @session).select { |s| s['value'] }
      return retval.first['value'] if retval.size > 0
      {}
    end

    def close
      op(:close, session: @session)
      @conn.close
    end
  end
end