Devise confirmation instructions test is not working - ruby-on-rails

Question

I am using request_confirmation_test.rb file from devise
confirmation test from devise
I have included the helper too but the file is showing errors on each line. Looks like something is missing that is necessary for the file to work correctly.This is the error that I am getting currently
ConfirmationInstructionsTest#test_set_up_sender_from_custom_mailer_defaults:
NoMethodError: undefined method `from' for nil:NilClass
test/integration/request_confirmation_test.rb:46:in `block in <class:ConfirmationInstructionsTest>'
this is my code for testing file
require 'test_helper'
class ConfirmationInstructionsTest < ActionMailer::TestCase
def setup
setup_mailer
Devise.mailer = 'Devise::Mailer'
Devise.mailer_sender = 'johnmax.rtc#gmail.com'
end
def teardown
Devise.mailer = 'Devise::Mailer'
Devise.mailer_sender = 'please-change-me#config-initializers-devise.com'
end
def user
#user ||= create_user
end
def mail
#mail ||= begin
user
ActionMailer::Base.deliveries.first
end
end
test 'email sent after creating the user' do
assert_not_nil mail
end
# test 'content type should be set to html' do
# assert mail.content_type.include?('text/html')
# end
test 'send confirmation instructions to the user email' do
mail
assert_equal [user.email], mail.to
end
test 'set up sender from configuration' do
assert_equal ['johnmax.rtc#gmail.com'], mail.from
end
test 'set up sender from custom mailer defaults' do
Devise.mailer = 'Users::Mailer'
assert_equal ['johnmax.rtc#gmail.com'], mail.from
end
# test 'set up sender from custom mailer defaults with proc' do
# Devise.mailer = 'Users::FromProcMailer'
# assert_equal ['johnmax.rtc#gmail.com'], mail.from
# end
# test 'custom mailer renders parent mailer template' do
# Devise.mailer = 'Users::Mailer'
# assert_present mail.body.encoded
# end
# test 'set up reply to as copy from sender' do
# assert_equal ['johnmax.rtc#gmail.com'], mail.reply_to
# end
# test 'set up reply to as different if set in defaults' do
# Devise.mailer = 'Users::ReplyToMailer'
# assert_equal ['johnmax.rtc#gmail.com'], mail.from
# assert_equal ['johnmax.rtc#gmail.com'], mail.reply_to
# end
test 'set up subject from I18n' do
store_translations :en, devise: { mailer: { confirmation_instructions: { subject: 'Account Confirmation' } } } do
assert_equal 'Account Confirmation', mail.subject
end
end
test 'subject namespaced by model' do
store_translations :en, devise: { mailer: { confirmation_instructions: { user_subject: 'User Account Confirmation' } } } do
assert_equal 'User Account Confirmation', mail.subject
end
end
test 'body should have user info' do
assert_match user.email, mail.body.encoded
end
test 'body should have link to confirm the account' do
host, port = ActionMailer::Base.default_url_options.values_at :host, :port
if mail.body.encoded =~ %r{<a href=\"http://#{host}:#{port}/users/confirmation\?confirmation_token=([^"]+)">}
assert_equal $1, user.confirmation_token
else
flunk "expected confirmation url regex to match"
end
end
# test 'renders a scoped if scoped_views is set to true' do
# swap Devise, scoped_views: true do
# assert_equal user.email, mail.body.decoded
# end
# end
# test 'renders a scoped if scoped_views is set in the mailer class' do
# begin
# Devise::Mailer.scoped_views = true
# assert_equal user.email, mail.body.decoded
# ensure
# Devise::Mailer.send :remove_instance_variable, :#scoped_views
# end
# end
test 'mailer sender accepts a proc' do
swap Devise, mailer_sender: proc { "another#example.com" } do
assert_equal ['another#example.com'], mail.from
end
end
end
This is the helper file
require 'active_support/test_case'
class ActiveSupport::TestCase
VALID_AUTHENTICATION_TOKEN = 'AbCdEfGhIjKlMnOpQrSt'.freeze
def setup_mailer
ActionMailer::Base.deliveries = []
end
def store_translations(locale, translations, &block)
# Calling 'available_locales' before storing the translations to ensure
# that the I18n backend will be initialized before we store our custom
# translations, so they will always override the translations for the
# YML file.
I18n.available_locales
I18n.backend.store_translations(locale, translations)
yield
ensure
I18n.reload!
end
def generate_unique_email
##email_count ||= 0
##email_count += 1
"test#{##email_count}#example.com"
end
def valid_attributes(attributes={})
{ first_name: "usertest",
email: generate_unique_email,
password: '12345678',
password_confirmation: '12345678' }.update(attributes)
end
def new_user(attributes={})
User.new(valid_attributes(attributes))
end
def create_user(attributes={})
User.create!(valid_attributes(attributes))
end
def create_admin(attributes={})
valid_attributes = valid_attributes(attributes)
valid_attributes.delete(:first_name)
Admin.create!(valid_attributes)
end
def create_user_without_email(attributes={})
UserWithoutEmail.create!(valid_attributes(attributes))
end
def create_user_with_validations(attributes={})
UserWithValidations.create!(valid_attributes(attributes))
end
# Execute the block setting the given values and restoring old values after
# the block is executed.
def swap(object, new_values)
old_values = {}
new_values.each do |key, value|
old_values[key] = object.send key
object.send :"#{key}=", value
end
clear_cached_variables(new_values)
yield
ensure
clear_cached_variables(new_values)
old_values.each do |key, value|
object.send :"#{key}=", value
end
end
def clear_cached_variables(options)
if options.key?(:case_insensitive_keys) || options.key?(:strip_whitespace_keys)
Devise.mappings.each do |_, mapping|
mapping.to.instance_variable_set(:#devise_parameter_filter, nil)
end
end
end
end
Any help would be highly appreciated.