Upgrade Ruby on Rails: 7.2 -> 8.0

Gemfile

@@ -5,7 +5,7 @@ gem 'bootsnap'
 gem 'pg'
 gem 'puma'
 gem 'puma_worker_killer'
-gem 'rails', '~> 7.2.0'
+gem 'rails', '~> 8.0.0'
 
 gem 'jbuilder'
 gem 'jquery-rails'

Gemfile.lock

@@ -1,66 +1,65 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (7.2.2.1)
-      actionpack (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    actioncable (8.0.2)
+      actionpack (= 8.0.2)
+      activesupport (= 8.0.2)
       nio4r (~> 2.0)
       websocket-driver (>= 0.6.1)
       zeitwerk (~> 2.6)
-    actionmailbox (7.2.2.1)
-      actionpack (= 7.2.2.1)
-      activejob (= 7.2.2.1)
-      activerecord (= 7.2.2.1)
-      activestorage (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    actionmailbox (8.0.2)
+      actionpack (= 8.0.2)
+      activejob (= 8.0.2)
+      activerecord (= 8.0.2)
+      activestorage (= 8.0.2)
+      activesupport (= 8.0.2)
       mail (>= 2.8.0)
-    actionmailer (7.2.2.1)
-      actionpack (= 7.2.2.1)
-      actionview (= 7.2.2.1)
-      activejob (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    actionmailer (8.0.2)
+      actionpack (= 8.0.2)
+      actionview (= 8.0.2)
+      activejob (= 8.0.2)
+      activesupport (= 8.0.2)
       mail (>= 2.8.0)
       rails-dom-testing (~> 2.2)
-    actionpack (7.2.2.1)
-      actionview (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    actionpack (8.0.2)
+      actionview (= 8.0.2)
+      activesupport (= 8.0.2)
       nokogiri (>= 1.8.5)
-      racc
-      rack (>= 2.2.4, < 3.2)
+      rack (>= 2.2.4)
       rack-session (>= 1.0.1)
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.2)
       rails-html-sanitizer (~> 1.6)
       useragent (~> 0.16)
-    actiontext (7.2.2.1)
-      actionpack (= 7.2.2.1)
-      activerecord (= 7.2.2.1)
-      activestorage (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    actiontext (8.0.2)
+      actionpack (= 8.0.2)
+      activerecord (= 8.0.2)
+      activestorage (= 8.0.2)
+      activesupport (= 8.0.2)
       globalid (>= 0.6.0)
       nokogiri (>= 1.8.5)
-    actionview (7.2.2.1)
-      activesupport (= 7.2.2.1)
+    actionview (8.0.2)
+      activesupport (= 8.0.2)
       builder (~> 3.1)
       erubi (~> 1.11)
       rails-dom-testing (~> 2.2)
       rails-html-sanitizer (~> 1.6)
-    activejob (7.2.2.1)
-      activesupport (= 7.2.2.1)
+    activejob (8.0.2)
+      activesupport (= 8.0.2)
       globalid (>= 0.3.6)
-    activemodel (7.2.2.1)
-      activesupport (= 7.2.2.1)
-    activerecord (7.2.2.1)
-      activemodel (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    activemodel (8.0.2)
+      activesupport (= 8.0.2)
+    activerecord (8.0.2)
+      activemodel (= 8.0.2)
+      activesupport (= 8.0.2)
       timeout (>= 0.4.0)
-    activestorage (7.2.2.1)
-      actionpack (= 7.2.2.1)
-      activejob (= 7.2.2.1)
-      activerecord (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    activestorage (8.0.2)
+      actionpack (= 8.0.2)
+      activejob (= 8.0.2)
+      activerecord (= 8.0.2)
+      activesupport (= 8.0.2)
       marcel (~> 1.0)
-    activesupport (7.2.2.1)
+    activesupport (8.0.2)
       base64
       benchmark (>= 0.3)
       bigdecimal
@@ -72,6 +71,7 @@ GEM
       minitest (>= 5.1)
       securerandom (>= 0.3)
       tzinfo (~> 2.0, >= 2.0.5)
+      uri (>= 0.13.1)
     addressable (2.8.7)
       public_suffix (>= 2.0.2, < 7.0)
     airbrake (13.0.5)
@@ -342,20 +342,20 @@ GEM
       woothee (>= 1.0.0)
     rackup (2.2.1)
       rack (>= 3)
-    rails (7.2.2.1)
-      actioncable (= 7.2.2.1)
-      actionmailbox (= 7.2.2.1)
-      actionmailer (= 7.2.2.1)
-      actionpack (= 7.2.2.1)
-      actiontext (= 7.2.2.1)
-      actionview (= 7.2.2.1)
-      activejob (= 7.2.2.1)
-      activemodel (= 7.2.2.1)
-      activerecord (= 7.2.2.1)
-      activestorage (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    rails (8.0.2)
+      actioncable (= 8.0.2)
+      actionmailbox (= 8.0.2)
+      actionmailer (= 8.0.2)
+      actionpack (= 8.0.2)
+      actiontext (= 8.0.2)
+      actionview (= 8.0.2)
+      activejob (= 8.0.2)
+      activemodel (= 8.0.2)
+      activerecord (= 8.0.2)
+      activestorage (= 8.0.2)
+      activesupport (= 8.0.2)
       bundler (>= 1.15.0)
-      railties (= 7.2.2.1)
+      railties (= 8.0.2)
     rails-controller-testing (1.0.5)
       actionpack (>= 5.0.1.rc1)
       actionview (>= 5.0.1.rc1)
@@ -367,9 +367,9 @@ GEM
     rails-html-sanitizer (1.6.2)
       loofah (~> 2.21)
       nokogiri (>= 1.15.7, != 1.16.7, != 1.16.6, != 1.16.5, != 1.16.4, != 1.16.3, != 1.16.2, != 1.16.1, != 1.16.0.rc1, != 1.16.0)
-    railties (7.2.2.1)
-      actionpack (= 7.2.2.1)
-      activesupport (= 7.2.2.1)
+    railties (8.0.2)
+      actionpack (= 8.0.2)
+      activesupport (= 8.0.2)
       irb (~> 1.13)
       rackup (>= 1.0.0)
       rake (>= 12.2)
@@ -506,6 +506,7 @@ GEM
     unicode-display_width (3.1.4)
       unicode-emoji (~> 4.0, >= 4.0.4)
     unicode-emoji (4.0.4)
+    uri (1.0.3)
     useragent (0.16.11)
     web-console (4.2.1)
       actionview (>= 6.0.0)
@@ -567,7 +568,7 @@ DEPENDENCIES
   rack-host-redirect
   rack-mini-profiler
   rack-user_agent
-  rails (~> 7.2.0)
+  rails (~> 8.0.0)
   rails-controller-testing
   rails-html-sanitizer
   rake

bin/dev

@@ -0,0 +1,2 @@
+#!/usr/bin/env ruby
+exec "./bin/rails", "server", *ARGV

bin/setup

@@ -2,7 +2,6 @@
 require "fileutils"
 
 APP_ROOT = File.expand_path("..", __dir__)
-APP_NAME = "coderdojo-jp"
 
 def system!(*args)
   system(*args, exception: true)
@@ -14,7 +13,6 @@ FileUtils.chdir APP_ROOT do
   # Add necessary setup steps to this file.
 
   puts "== Installing dependencies =="
-  system! "gem install bundler --conservative"
   system("bundle check") || system!("bundle install")
 
   # puts "\n== Copying sample files =="
@@ -56,10 +54,9 @@ FileUtils.chdir APP_ROOT do
   puts "\n== Removing old logs and tempfiles =="
   system! "bin/rails log:clear tmp:clear"
 
-  puts "\n== Restarting application server =="
-  system! "bin/rails restart"
-
-  # puts "\n== Configuring puma-dev =="
-  # system "ln -nfs #{APP_ROOT} ~/.puma-dev/#{APP_NAME}"
-  # system "curl -Is https://#{APP_NAME}.test/up | head -n 1"
+  unless ARGV.include?("--skip-server")
+    puts "\n== Starting development server =="
+    STDOUT.flush # flush the output before exec(2) so that it displays
+    exec "bin/dev"
+  end
 end

config/application.rb

@@ -32,5 +32,13 @@ class Application < Rails::Application
 
     # Fixture paths
     config.fixture_paths = [Rails.root.join('spec/fixtures')]
+
+    # TODO: The following config should be switched to its default value `true`, but not urgent.
+    # Rails 5.0: Require `belongs_to` associations by default. Previous versions had false.
+    # https://railsguides.jp/configuring.html#config-active-record-belongs-to-required-by-default
+    config.active_record.belongs_to_required_by_default = false
+
+    # Rails 8.0: `to_time` will always preserve the full timezone in Rails 8.1.
+    config.active_support.to_time_preserves_timezone = :zone
   end
 end

config/environments/development.rb

@@ -3,9 +3,7 @@
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
-  # In the development environment your application's code is reloaded any time
-  # it changes. This slows down response time but is perfect for development
-  # since you don't have to restart the web server when you make code changes.
+  # Make code changes take effect immediately without server restart.
   config.enable_reloading = true
 
   # Do not eager load code on boot.
@@ -17,53 +15,47 @@
   # Enable server timing.
   config.server_timing = true
 
-  # Enable/disable caching. By default caching is disabled.
-  # Run rails dev:cache to toggle caching.
+  # Enable/disable Action Controller caching. By default Action Controller caching is disabled.
+  # Run rails dev:cache to toggle Action Controller caching.
   if Rails.root.join("tmp/caching-dev.txt").exist?
     config.action_controller.perform_caching = true
     config.action_controller.enable_fragment_cache_logging = true
-
-    config.cache_store = :memory_store
-    config.public_file_server.headers = { "Cache-Control" => "public, max-age=#{2.days.to_i}" }
+    config.public_file_server.headers = { "cache-control" => "public, max-age=#{2.days.to_i}" }
   else
     config.action_controller.perform_caching = false
-
-    config.cache_store = :null_store
   end
 
+  # Change to :null_store to avoid any caching.
+  config.cache_store = :memory_store
+
   # Store uploaded files on the local file system (see config/storage.yml for options).
   config.active_storage.service = :local
 
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false
 
-  # Disable caching for Action Mailer templates even if Action Controller
-  # caching is enabled.
+  # Make template changes take effect immediately.
   config.action_mailer.perform_caching = false
+
+  # Set localhost to be used by links generated in mailer templates.
   config.action_mailer.default_url_options = { host: "localhost", port: 3000 }
   config.action_mailer.delivery_method = :letter_opener_web
 
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 
-  # Raise exceptions for disallowed deprecations.
-  config.active_support.disallowed_deprecation = :raise
-
-  # Tell Active Support which deprecation messages to disallow.
-  config.active_support.disallowed_deprecation_warnings = []
-
   # Raise an error on page load if there are pending migrations.
   config.active_record.migration_error = :page_load
 
   # Highlight code that triggered database queries in logs.
   config.active_record.verbose_query_logs = true
 
+  # Append comments with runtime information tags to SQL queries in logs.
+  config.active_record.query_log_tags_enabled = true
+
   # Highlight code that enqueued background job in logs.
   config.active_job.verbose_enqueue_logs = true
 
-  # Suppress logger output for asset requests.
-  config.assets.quiet = true
-
   # Raises error for missing translations.
   # config.i18n.raise_on_missing_translations = true