Single-file Rails app experiment

app.ru

# frozen_string_literal: true

# Run this app as: puma app.ru
# Most of this was taken from: https://greg.molnar.io/blog/a-single-file-rails-application/

require 'bundler/inline'

gemfile(true) do
  source 'https://rubygems.org'

  gem 'rails', '~> 7.2.0'
  gem 'puma', '~> 6.4.2'
  gem 'sqlite3', '~> 2.0.4'
end

require 'rails/all'

database = 'development.sqlite3'
ENV['DATABASE_URL'] = "sqlite3:#{database}"
ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: database)

ActiveRecord::Base.logger = Logger.new(STDOUT)
Rails.logger = Logger.new(STDOUT)

ActiveRecord::Schema[7.2].define do
  # Let's re-create the table unless it already exists.
  create_table :posts, force: false, if_not_exists: true do |t|
  end

  create_table :comments, force: false, if_not_exists: true do |t|
    t.integer :post_id
  end
end


class App < Rails::Application
  config.eager_load = true
  config.root = __dir__
  config.consider_all_requests_local = true
  config.secret_key_base = 'i_am_a_secret'
  config.action_dispatch.default_headers = { 'X-Frame-Options' => 'ALLOWALL' }
  config.active_storage.service_configurations = { 'local' => { 'service' => 'Disk', 'root' => './storage' } }

  routes.append do
    root to: 'welcome#index'
  end
end

class ApplicationRecord < ActiveRecord::Base
  primary_abstract_class
end

class Post < ApplicationRecord
end

class ApplicationController < ActionController::Base
  # Only allow modern browsers supporting webp images, web push, badges, import maps, CSS nesting, and CSS :has.
  allow_browser versions: :modern
end

class WelcomeController < ApplicationController
  def index
    render inline: Post.new.inspect
  end
end

App.initialize!

run App