Rails 7 is the latest version of the popular web development framework that powers many websites and applications. It brings a lot of new features and improvements that make Rails development faster, easier, and more enjoyable.

Here are some of the most notable changes and benefits that 7th edition offers, and best practices for upgrading your existing Rails applications.

Rails 7: New Features and Improvements


Hotwire is a new way of building modern web applications with Rails, without writing much JavaScript. It consists of two parts: Turbo and Stimulus. Turbo is a set of techniques and libraries that make your web pages load and render faster, using HTML over the wire instead of JSON. Stimulus is a lightweight JavaScript framework that lets you add interactivity and behavior to your HTML elements, using data attributes. Together, they enable you to create rich and dynamic user interfaces
with minimal code and complexity.

CSS Bundling and Minification:

Rails 7 introduces a new way of managing your CSS assets, using esbuild. Esbuild is a fast and modern bundler and minifier for JavaScript and CSS, written in Go. It allows you to use the latest CSS features, such as modules, variables, and custom properties, without worrying about browser compatibility or performance. You can also use popular CSS preprocessors, such as Sass or Less, with esbuild. Rails 7 automatically sets up esbuild for you, so you don’t have to configure anything.

Import Maps:

Import maps are a new standard for loading JavaScript modules in the browser, without using a bundler. They let you map module names to URLs, so you can import them directly in your script tags. For example, you can import React from a CDN, without having to install it locally or bundle it with your code. Import maps are supported by Rails 7 out of the box, so you can use them to organize and load your JavaScript modules easily and efficiently.

Encrypted Cookies:

Rails 7 adds a new option to encrypt your cookies, instead of just signing them. This adds an extra layer of security and privacy to your application, as it prevents anyone from reading or tampering with your cookie data. You can enable encrypted cookies by setting `config.action_dispatch.use_cookies_with_metadata = true` in
your application.rb file. You can also choose which cookies to encrypt and which ones to sign, by using the `:encrypted` or `:signed` options when setting or reading cookies.

Parallel Testing:

Rails 7 improves the parallel testing feature that was introduced in Rails 6, by  adding support for more test frameworks and runners, such as RSpec, Minitest, and Spring. Parallel testing allows you to run your tests in multiple processes or threads, which can significantly speed up your test suite. You can enable parallel testing by setting `parallelize(workers: n)` in your test_helper.rb or rails_helper.rb file, where n is the number of processes or threads you want to use. In addition to the aforementioned updates, Rails 7 also includes many other changes and enhancements, such as:
● The ‘–minimal flag’ for ‘rails new’, generating a bare-bones application with essential gems and configurations.
● The ‘–api flag’ for ‘rails generate scaffold’, creating a JSON API scaffold with necessary files and code.
● The ‘rails restart’ command, allows the server to restart without stopping Spring or webpacker.
● The ‘config.generators.after_generate’ hook, enabling custom code execution after generating files with Rails generators.
● The ‘ActiveSupport::CurrentAttributes’ module, providing thread-safe access to global variables.
● The ‘ActiveStorage::Service::MirrorService’ class, enabling mirroring of
uploaded files for redundancy and backup.
● The ‘ActiveRecord::Relation#excluding’ method, excluding records from a relation based on primary keys.
● The ‘ActiveRecord::Base.strict_loading_by_default’ option, enabling strict loading mode for associations by default.
● The ‘ActionController::API class’, a lighter and faster alternative for API-only applications derived from ‘ActionController::Metal’.
● The ‘ActionView::Component’ class, facilitating the creation of reusable view  components using Ruby code and HTML templates.

Rails 7: Best Practices to Upgrade

Here are some tips to make upgrading your existing Rails applications to Rails 7 a smooth and rewarding process.

Follow Official Guides:

The official Rails guides provide detailed instructions on how to upgrade from different versions of Rails to Rails 7. They cover the changes and deprecations that you need to be aware of, and the steps that you need to take to migrate your code and configuration.

Use Dual Booting:

Dual booting is a technique that lets you run your application with two differentversions of Rails, using a gemfile switcher. This can help you test and debug your application with Rails 7, without affecting your production environment or your other developers. You can use the `next` gem to set up dual booting for your application.

Run Test Scenarios:

Running your test suite is a great way to check if your application works as expected with Rails 7. You can also use tools like `deprecation_toolkit` or `rails- deprecated` to track and fix any deprecation warnings that Rails 7 may raise.

Use the Latest Ruby Version:

Rails 7 requires Ruby 2.7 or higher, and works best with Ruby 3.0 or higher. Using the latest Ruby version can also bring you performance and security benefits, as well as new features and syntax improvements. You can use tools like `rbenv` or `rvm` to manage multiple Ruby versions on your system.

Review Dependencies:

Before upgrading to Rails 7, you should review your dependencies and make sure they are compatible with Rails 7. You can use tools like `bundle outdated` or `bundler-audit` to check for outdated or vulnerable gems in your Gemfile.

Follow the Rails Community:

The Rails community is a valuable source of information and support for upgrading to Rails 7. You can follow the official Rails blog, Twitter account, and GitHub repository to stay updated on the latest news and releases. You can also join the Rails Discord server, where you can chat with other Rails developers and ask for help if you encounter any issues