Creating Signed Cookies in Capybara

profile_management_spec.rb

# spec/features/profile_management_spec.rb

require 'rails_helper'

feature 'Profile Management', type: :feature do
  given!(:user) { create(:user) }

  scenario 'User updates profile' do
    cookie = SignedCookieGenerator.new(:auth, user.id)
    page.driver.browser.set_cookie(cookie.to_s)
    visit '/account/profile'

    expect(page).to have_text('Profile Page')
  end
end

signed_cookie_generator.rb

# spec/support/signed_cookie_generator.rb

class SignedCookieGenerator
  attr_accessor :name, :value

  def initialize(name, value)
    @name = name.to_sym
    @value = value
    @cookie_jar = ActionDispatch::Cookies::CookieJar.new(ActiveSupport::KeyGenerator.new(Rails.application.secrets.secret_key_base), Capybara.default_host, false, signed_cookie_salt: Rails.configuration.action_dispatch.encrypted_signed_cookie_salt)
  end

  def to_s
    "#{name}=#{signed_cookie_value};"
  end

  def signed_cookie_value
    @cookie_jar.signed[name] = {value: value}
    Rack::Utils.escape(@cookie_jar[name])
  end
end

Blog post where this code snippet is posted: http://terenceponce.com/post/129755084060/creating-signed-cookies-in-capybara