This post covers how to run on Rails main rather than a released version for developing your web application.
Creating a new Rails App
The way to create a new Rails app on edge is to add the --main flag when you create a new Rails app.
$ rails new app_on_main --main --skip-test --javascript=esbuild --css=tailwind --database=sqlite3
You’ll see a lot of text fly by as it sets things up.
$ rails new app_on_main --main --skip-test --javascript=esbuild --css=tailwind --database=sqlite3
create
create Gemfile
run bundle install
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Resolving dependencies...
Fetching gem metadata from https://rubygems.org/..........
Fetching reline 0.5.2
Installing reline 0.5.2
Bundle complete! 1 Gemfile dependency, 58 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.
run bundle exec rails new d:/projects/rails/trial/app_on_main --main --skip-test --javascript\=esbuild --css\=tailwind --database\=sqlite3
exist
remove Gemfile
remove Gemfile.lock
create README.md
create Rakefile
create .ruby-version
create config.ru
create .gitignore
create .gitattributes
create Gemfile
run git init from "."
Initialized empty Git repository in D:/projects/rails/trial/app_on_main/.git/
create app
create app/assets/config/manifest.js
create app/assets/stylesheets/application.css
create app/channels/application_cable/channel.rb
create app/channels/application_cable/connection.rb
create app/controllers/application_controller.rb
create app/helpers/application_helper.rb
create app/jobs/application_job.rb
create app/mailers/application_mailer.rb
create app/models/application_record.rb
create app/views/layouts/application.html.erb
create app/views/layouts/mailer.html.erb
create app/views/layouts/mailer.text.erb
create app/views/pwa/manifest.json.erb
create app/views/pwa/service-worker.js
create app/assets/images
create app/assets/images/.keep
create app/controllers/concerns/.keep
create app/models/concerns/.keep
create bin
create bin/brakeman
create bin/rails
create bin/rake
create bin/rubocop
create bin/setup
create Dockerfile
create .dockerignore
create bin/docker-entrypoint
create .rubocop.yml
create .github/workflows
create .github/workflows/ci.yml
create .github/dependabot.yml
create config
create config/routes.rb
create config/application.rb
create config/environment.rb
create config/cable.yml
create config/puma.rb
create config/storage.yml
create config/environments
create config/environments/development.rb
create config/environments/production.rb
create config/environments/test.rb
create config/initializers
create config/initializers/assets.rb
create config/initializers/content_security_policy.rb
create config/initializers/cors.rb
create config/initializers/enable_yjit.rb
create config/initializers/filter_parameter_logging.rb
create config/initializers/inflections.rb
create config/initializers/new_framework_defaults_7_2.rb
create config/initializers/permissions_policy.rb
create config/locales
create config/locales/en.yml
create config/master.key
append .gitignore
create config/boot.rb
create config/database.yml
create db
create db/seeds.rb
create lib
create lib/tasks
create lib/tasks/.keep
create lib/assets
create lib/assets/.keep
create log
create log/.keep
create public
create public/404.html
create public/406-unsupported-browser.html
create public/422.html
create public/500.html
create public/icon.png
create public/icon.svg
create public/robots.txt
create tmp
create tmp/.keep
create tmp/pids
create tmp/pids/.keep
create vendor
create vendor/.keep
create storage
create storage/.keep
create tmp/storage
create tmp/storage/.keep
create .devcontainer
create .devcontainer/devcontainer.json
create .devcontainer/Dockerfile
create .devcontainer/compose.yaml
remove config/initializers/cors.rb
remove config/initializers/new_framework_defaults_7_2.rb
run bundle install --quiet
run bundle lock --add-platform=x86_64-linux
Fetching gem metadata from https://rubygems.org/..........
Resolving dependencies...
Writing lockfile to d:/projects/rails/trial/app_on_main/Gemfile.lock
run bundle binstubs bundler
rails importmap:install
apply D:/Ruby33-x64/lib/ruby/gems/3.3.0/gems/importmap-rails-2.0.1/lib/install/install.rb
Add Importmap include tags in application layout
insert app/views/layouts/application.html.erb
Create application.js module as entrypoint
create app/javascript/application.js
Use vendor/javascript for downloaded pins
create vendor/javascript
create vendor/javascript/.keep
Ensure JavaScript files are in the Sprocket manifest
append app/assets/config/manifest.js
Configure importmap paths in config/importmap.rb
create config/importmap.rb
Copying binstub
create bin/importmap
run bundle install --quiet
rails turbo:install stimulus:install
apply D:/Ruby33-x64/lib/ruby/gems/3.3.0/gems/turbo-rails-2.0.5/lib/install/turbo_with_importmap.rb
Import Turbo
append app/javascript/application.js
Pin Turbo
append config/importmap.rb
run bundle install --quiet
Run turbo:install:redis to switch on Redis and use it in development for turbo streams
apply D:/Ruby33-x64/lib/ruby/gems/3.3.0/gems/stimulus-rails-1.3.3/lib/install/stimulus_with_importmap.rb
Create controllers directory
create app/javascript/controllers
create app/javascript/controllers/index.js
create app/javascript/controllers/application.js
create app/javascript/controllers/hello_controller.js
Import Stimulus controllers
append app/javascript/application.js
Pin Stimulus
Appending: pin "@hotwired/stimulus", to: "stimulus.min.js"
append config/importmap.rb
Appending: pin "@hotwired/stimulus-loading", to: "stimulus-loading.js"
append config/importmap.rb
Pin all controllers
Appending: pin_all_from "app/javascript/controllers", under: "controllers"
append config/importmap.rb
run bundle install --quiet
If you go into the Gemfile, you will see that this is how Rails is set up.
# Use main development branch of Rails
gem "rails", github: "rails/rails", branch: "main"
After this, just use ruby bin\rails [whatever] for your needs.
$ ruby bin\rails s
=> Booting Puma
=> Rails 7.2.0.alpha application starting in development
=> Run `bin/rails server --help` for more startup options
*** SIGUSR2 not implemented, signal based restart unavailable!
*** SIGUSR1 not implemented, signal based restart unavailable!
*** SIGHUP not implemented, signal based logs reopening unavailable!
Puma starting in single mode...
* Puma version: 6.4.2 (ruby 3.3.0-p0) ("The Eagle of Durango")
* Min threads: 3
* Max threads: 3
* Environment: development
* PID: 2976
* Listening on http://[::1]:3000
* Listening on http://127.0.0.1:3000
Use Ctrl-C to stop
If you go to http://localhost:3000/ you will see the Rails welcome page.
Updating Rails
If you need to do an update, just go ahead and do:
$ gem update railsEnjoy programming with Rails.
One issue
If you use this on Windows, you might encounter a Rubocop issue – see this post for the details and the fix for now.