app.rb

require 'sinatra'
require 'bundler/setup'
require 'json'
require 'line/bot'

ActiveRecord::Base.establish_connection(ENV['DATABASE_URL'] || 'sqlite3://localhost/appdb')
class User < ActiveRecord::Base; end

def client
  @client ||= LINE::Bot::Client.new { |config|
    config.channel_secret = ENV['SECRET']
    config.channel_token = ENV['TOKEN']
  }
end