Upgrade Example App to Rails 7 and Ruby 3.2.2

This upgrades the example application from Rails 3.2 to Rails 7 and Ruby
3.2.2.

Over the last 3 weeks I've been joined by developers from across
thoughtbot to live stream us working on this upgrade together. You can
watch the series at
https://www.youtube.com/watch?v=gQIYXc8y-UM&list=PL8tzorAO7s0huVF53GLeKbqNmMbwJ5JGF

As we made necessary changes we attempted to minimize changes to the
text of the book, but there were a few necessary changes, which are
included along here in addition to the example app upgrade.

book/code_smells/duplicated_code.md

@@ -37,7 +37,7 @@ def update
   question_params = params.
     require(:question).
     permit(:title, :options_attributes, :minimum, :maximum)
-  @question.update_attributes(question_params)
+  @question.update(question_params)
 
   if @question.save
     redirect_to @question.survey

book/solutions/extract_validator.md

@@ -58,6 +58,10 @@ is validated against it.
 
 ` app/validators/enumerable_validator.rb@21f7a57
 
+Please note that in the latest version of the example application the
+`EmailValidator` class was renamed to `EmailAddressValidator` to avoid a naming
+conflict with an external gem.
+
 ### Next Steps
 
 * Verify the extracted validator does not have any [long methods](#long-methods).

book/solutions/replace_conditional_with_polymorphism.md

@@ -153,7 +153,7 @@ to the appropriate class. First, let's move the method
 class MultipleChoiceQuestion < Question
   def summary
     total = answers.count
-    counts = answers.group(:text).order('COUNT(*) DESC').count
+    counts = answers.group(:text).order(Arel.sql('COUNT(*) DESC')).count
     percents = counts.map do |text, count|
       percent = (100.0 * count / total).round
       "#{percent}% #{text}"

example_app/.tool-versions

@@ -0,0 +1 @@
+ruby 3.2.2

example_app/Gemfile

@@ -1,29 +1,29 @@
 source 'https://rubygems.org'
 
-gem 'rails', '3.2.8'
+ruby '3.2.2'
+
+gem 'rails', '7.0.8'
 
 gem 'clearance'
-gem 'jquery-rails'
 gem 'simple_form'
-gem 'strong_parameters'
 gem 'sqlite3'
-gem 'thin'
-
-group :assets do
-  gem 'coffee-rails', '~> 3.2'
-  gem 'sass-rails', '~> 3.2'
-  gem 'uglifier', '>= 1.0'
-end
+gem 'sprockets-rails'
+gem 'puma'
+gem 'importmap-rails'
+gem "tzinfo-data", platforms: %i[ mingw mswin x64_mingw jruby ]
+gem 'bootsnap', require: false
 
 group :development, :test do
-  gem 'bourne'
+  gem 'bourne', '1.3.0'
   gem 'foreman'
   gem 'rspec-rails'
+  gem 'rails-dom-testing'
+  gem 'listen'
 end
 
 group :test do
   gem 'capybara'
   gem 'email_spec'
-  gem 'factory_girl_rails'
+  gem 'factory_bot_rails'
   gem 'shoulda-matchers'
 end