unsubscribe all deleted channel with firefox.

client.rb

require 'json'
class Client

  def initialize
    path = "client_secrets.json"
    begin
      json = open(path) do |io|
        JSON.load(io)
      end
      @json = json
    rescue => e
      puts "#{e}"
    end
  end

  def id
    @json["id"]
  end

  def password
    @json["password"]
  end
end

Gemfile

# A sample Gemfile
source "https://rubygems.org"

gem "selenium-webdriver"

unsubscribe_deleted_channel.rb

require "selenium-webdriver"
require_relative 'client.rb'

client = Client.new

driver = Selenium::WebDriver.for :firefox

#login
driver.navigate.to 'https://www.youtube.com/?hl=ja&gl=JP'
driver.find_element(:xpath, '//*[@id="yt-masthead-signin"]/button').click
driver.find_element(:name, 'Email').send_keys(client.id)
driver.find_element(:name, 'Passwd').send_keys(client.password)
driver.find_element(:xpath, '//*[@id="signIn"]').click

# list
elements = driver.find_elements(:css, '.guide-channels-list a')
links = elements.map {|e| e.attribute("href")}
links.each do |url|
  next unless url.include?("channel")
  driver.navigate.to url
  title_element = driver.find_element(:class, 'branded-page-header-title')
  if title_element.text.empty?
    puts "remove"
    driver.find_element(:xpath, '//*[@id="c4-primary-header-contents"]/div/span/button[1]').click
  else
    puts title_element.text
  end
end

driver.quit