The file in the tutorial crash the heroku site

[jun-jing]

test/helpers/application_helper_test.rb

require 'test_helper'
class ApplicationHelperTest < ActionView::TestCase
  test "full title helper" do
    assert_equal full_title, FILL_IN
    assert_equal full_title("Help"), FILL_IN
  end
end

Above is the code in the book(Chapter6's final part which ask me to push the code to heroku), and I need to comment the require 'test_helper' and push it to heroku, otherwise the heorku site will crash.

Gemfile like below(guess it can serve some information to let you know my env):

source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '2.6.3'

gem 'active_storage_validations', '0.8.9'
gem 'bcrypt',                     '3.1.13'
gem 'bootsnap',                   '1.7.2', require: false
gem 'bootstrap-sass',             '3.4.1'
gem 'bootstrap-will_paginate',    '1.0.0'
gem 'faker',                      '2.11.0'
gem 'htmlbeautifier'
gem 'image_processing', '1.9.3'
gem 'jbuilder', '2.10.0'
gem 'mini_magick', '4.9.5'
gem 'puma', '5.2.2'
gem 'rails', '6.1.3.1'
gem 'sass-rails', '6.0.0'
gem 'turbolinks', '5.2.1'
gem 'webpacker', '5.2.1'
gem 'will_paginate', '3.3.0'

group :development, :test do
  gem 'byebug',  '11.1.3', platforms: %i[mri mingw x64_mingw]
  gem 'sqlite3', '1.4.2'
end

group :development do
  gem 'listen',             '3.4.1'
  gem 'rack-mini-profiler', '2.3.1'
  gem 'solargraph'
  gem 'spring', '2.1.1'
  gem 'web-console', '4.1.0'
end

group :test do
  gem 'capybara',                 '3.35.3'
  gem 'guard',                    '2.16.2'
  gem 'guard-minitest',           '2.4.6'
  gem 'minitest',                 '5.11.3'
  gem 'minitest-reporters',       '1.3.8'
  gem 'rails-controller-testing', '1.0.5'
  gem 'selenium-webdriver',       '3.142.7'
  gem 'webdrivers',               '4.6.0'
end

group :production do
  gem 'aws-sdk-s3', '1.87.0', require: false
  gem 'pg',         '1.2.3'
end
.
.
.

By the way, the book is really helpful, thanks for your effort.
Best regards.

[mhartl]

Thanks for the comment. The parts labeled FILL_IN are from the exercises and indicate that you need to fill in the corresponding places with valid code. By themselves, they are not valid Ruby, which could account for your application crashing at Heroku.