This Week in Rails

September 29, 2023

This Week in Rails - September 29

Hi, Wojtek here. The Rails World starts next week. Three members of the current This Week In Rails editorial team — Greg, Emmanuel, and myself — will be in attendance. We’ve got some stickers featuring the newsletter’s logo, so be sure to spot us to snag one! Now, let’s delve into the latest updates in the Rails codebase.

Rails 7.1.0.rc1 released
Getting us closer to the final release of the Rails 7.1.

Add a public API for broadcasting logs
This feature existed for a while but was until now a private API. Broadcasting log allows to send log message to difference sinks (STDOUT, file, etc.) and is used by default in the development environment to write logs both on STDOUT and in the “development.log” file.

broadcast =,"development.log"))"Hello!") # The "Hello!" message is written on STDOUT and in the log file.

Allow attaching File or Pathname to has_one_attached

This might be especially handy when creating models in tests, as it’s easier to pass a File or a Pathname (from file_fixture for instance)

User.create!(avatar: file_fixture("image.jpg"))

Introduce ActionView::TestCase.register_parser

Register a callable to decode rendered content for a given MIME type.
Each registered parser will also define a #rendered.$MIME helper method, where $MIME corresponds to the value of the mime argument.

register_parser :rss, -> rendered { RSS::Parser.parse(rendered) }

By default, parsers for :html and :json are registered.

HTML tag validation added for tag names
Added validation for HTML tag names in the tag and content_tag helper method. Those methods now check that the provided tag name adheres to the HTML specification. If an invalid HTML tag name is provided, the method raises an ArgumentError with an appropriate error message.

Add expires_at option to ActiveStorage::Blob#signed_id
Providing expires_at will expire the link after given the time:

rails_blob_path(user.avatar, disposition: "attachment", expires_at: 30.minutes.from_now)

Introduce ActionMailer::FormBuilder

Use the default_form_builder method in mailers to set the default form builder for templates rendered by that mailer. Matches the behavior in Action Controller.

Factor out deep_merge into Active Support DeepMergeable
The ActiveSupport::DeepMergeable module allows a class to provide deep_merge and deep_merge! methods simply by implementing a merge!(other, &block) method. Values will be deep merged only when they are compatible, according to deep_merge? method. By default, that only includes instances of the same class or its subclasses. A class may override deep_merge? to further restrict or expand the domain of deep mergeable values.
This allowed to support deep_merge on ActionController::Parameters

Fix Range#overlap? ignoring empty ranges
Previously, #overlap? would incorrectly return true when one of the ranges was effectively “empty”.
Ruby 3.3 introduces Range#overlap? so this also ensures that both implementations return same results.

Performance tune the SQLite3 adapter connection configuration
For Rails applications, the Write-Ahead-Log in normal syncing mode with a capped journal size, a healthy shared memory buffer and a shared cache will perform, on average, 2× better.

Allow SQLite3 busy_handler to be configured with simple max number of retries
Retrying busy connections without delay is a preferred practice for performance-sensitive applications. Add support for a database.yml retries integer, which is used in a simple busy_handler function to retry busy connections without exponential backoff up to the max number of retries.

Set Active Job scheduled_at attribute as a Time object
Serialize and deserialize the value of scheduled_at as a Time object. Deserialize enqueued_at as a Time object as well. In addition assigning a numeric/epoch value to scheduled_at= is deprecated.

Fix duplicate escaping of quotes for check constraint expressions in MySQL schema
A check constraint with an expression, that already contains quotes, lead to an invalid schema dump with the mysql2 adapter.

You can view the whole list of changes here.
We had 39 contributors to the Rails codebase this past week!

Until next time!

About This Week in Rails

Your weekly inside scoop of interesting commits, pull requests and more from Rails.