Rails 5.1.0.beta1: Loving JavaScript, System Tests, Encrypted Secrets, and more

Rails 5.0 was released just some eight months ago, and now, some 3500 commits later, we’re already close to the next big release. And what release this version 5.1 is lining up to be! We’ve made great strides on long-term promises and key ergonomics while also spring cleaning a bunch of deprecated code.

Let me walk you through the highlight reel:

Loving JavaScript

We’ve had a stormy, perhaps even contentious, relationship with JavaScript over the years. But that time is past. JavaScript has improved immensely over the past few years, particularly with the advent of ES6, and with package and compilation tools like Yarn and Webpack. Rails is embracing both of these solutions with open arms and letting whatever past water flow under the bridge.

JavaScript and Ruby share a deep philosophical bond over language design, if not ecosystem management. Let’s focus on the aspects we have in common and help Rails programmers extract the best from JavaScript with the help of some key guiding conventions.

The improvements in Rails 5.1 focus on three major parts:

  1. Manage JavaScript dependencies from NPM via Yarn. Think of Yarn like Bundler for JavaScript (it even has Yehuda Katz involved!). This makes it easy to depend on libraries like React or anything else from NPM. Everything you depend on via Yarn is then made available to be required in the asset pipeline, just like vendored dependencies would have been. Just use the binstub bin/yarn to add dependencies.

  2. Optionally compile JavaScript with Webpack. While there are a million different module bundlers/compilers for JavaScript, Webpack is quickly emerging as the preeminent choice. We’ve made it easy to use Webpack with Rails through the new Webpacker gem that you can configure automatically on new projects with --webpack. This is fully compatible with the asset pipeline, which you can continue to use for images, fonts, sounds, whatever. You can even have some JavaScript on the asset pipeline and some done via Webpack. It’s all managed via Yarn that’s on by default.

  3. Drop jQuery as a default dependency. We used to require jQuery in order to provide features like data-remote, data-confirm, and the other parts of Rails UJS. This dependency is no longer necessary as we’ve rewritten rails-ujs to use vanilla JavaScript. You’re of course still free to use jQuery, but you no longer have to.

Thanks to Liceth Ovalles for her work on Yarn integration, Dangyi Liu for his work on rails-ujs, and Guillermo Iguaran for chaperoning the whole thing!

System tests

In my 2014 keynote at RailsConf, I spoke at length about how an over focus on unit tests (and TDD) has lead us astray. While unit tests are part of a complete testing solution, they’re not the most important one. Integration tests that verify behavior all the way from controllers through models and views should play a much bigger part. Rails already has a great answer for these baked in.

But integration tests do not help you test the entire system, if that system relies on JavaScript. And most major web systems today rely at least to some extent on JavaScript. That’s where system tests driven by a real browser come in.

There’s long been an answer for system tests like this in Ruby called Capybara. It’s just been kind of a journey to configure properly for Rails. So now we’ve baked them straight into the framework! You get a lovely wrapping of Capybara that’s preconfigured for Chrome and enhanced to provide failure screenshots as part of Action Dispatch. You also don’t have to worry about extra database cleanup strategies anymore because the baked in transactional tests now rollback system test changes.

These tests are not without trade-offs. It’s of course still slower to run through a whole browser setup than just test a model with a stubbed out database. But it also tests so much more. You’d do well to familiarize yourself with system tests and have them as part of your testing answer.

Thanks to Eileen M. Uchitelle for her work extracting this from Basecamp!

Encrypted secrets

If you’re checking production passwords, API keys, and other secrets undisguised into your revision control system, you’re doing it wrong. That’s not safe and you should stop it! Now that’s an easy prescription, but without a coherent answer to what you should do instead, it’s also not that helpful.

People have long been loading up the ENV to store these secrets or used a variety of other solutions. There are all sorts of trade-offs and drawbacks to the ENV-model, not least of which that you still need to store those secrets for real somewhere else.

Inspired by Ara T. Howard’s sekrets gem, we’ve built encrypted secrets management into Rails 5.1. You can setup a new encrypted secrets file with bin/rails secrets:setup. That’ll generate a master key you’ll store outside of the repository, but allow you to commit the actual production secrets to your revision control. They’re then decrypted in production either through an injected key file or through RAILS_MASTER_KEY in the ENV.

Thank you to Kasper Timm Hansen for the work on this and Ara for the inspiration!

Parameterized mailers

Action Mailer is modeled on Action Controller. It shares underpinnings through Abstract Controller, but it’s long been disadvantaged from its controller cousin in the way it can share logic between actions.

In Action Controller, it’s common to use before_action and similar callbacks to extract logic that applies to multiple actions. This is doable because the params hash is available before the action is invoked. But in Action Mailer, we’ve been using regular method signatures with explicit arguments, so those arguments haven’t been available to filters that run before the actions.

With Parameterized Mailers, we now give you the option of calling mailers with parameters that, like in controllers, are available before the action is invoked. This combines with the default to/from/reply_to headers to dramatically DRY-up some mailer actions.

It’s completely backwards compatible and you can convert just the mailers that stand to gain the most from extraction first.

Direct & resolved routes

We have a lovely, simple API for declaring new resource routes. But if you’d like to add new programmatic routes that has logic determining the final destination based on the parameters, well, you’d have to row your own boat with helpers and other messy approaches.

With directed routes, you can now declare programmatic routes that have the full power of Ruby to do different things depending on the parameters passed.

With resolved routes, you can reprogram the polymorphic look-up for models based straight to compatible methods. So this allow you to turn link_to @comment into a final route like message_path(@comment.parent, anchor: "comment_#{@comment.id}").

Thank you to Andrew White for making all this work!

Unify form_tag/form_for with form_with

We’ve long had two parallel structures for creating forms. Those that were based off records through form_for, where we used convention over configuration to extract the details, and manually configured ones using form_tag. Now we’ve unified these two hierarchies with form_with. A single root tree that you can configure through an inferred record or manually. It’s much nicer and simpler.

Thanks to Kasper Timm Hansen for this one too!

Everything else

In addition to the highlight reel, we have hundreds of other fixes and improvements across all the frameworks. Please peruse the CHANGELOGs to acquaint yourself with all the goodies:

Your release manager for Rails 5.1 is Rafael França. He’ll be chaperoning us through the betas, release candidates, and onto the final release in advance of RailsConf 2017.

As per our maintenance policy, the release of Rails 5.1 will mean that bug fixes will only apply to 5.1.x, regular security issues to 5.1.x and 5.0.x, and severe security issues to 5.1.x, 5.0.x, and 4.2.x. This means 4.x and below will essentially be unsupported!

Please help us test this beta version of Rails. It’s always frustrating when we put a lot of work into a new release, betas, release candidates, and then get people report all sorts of issues on week one of the final release. Basecamp 3 is already running this beta in production. This is an incremental upgrade to Rails 5.0. Please do your community duty and help us land a solid 5.1 without needing an immediate 5.1.1. Thank you! Gracias! Merci! TAK!

Eileen joins Rails core

We’re proud to welcome Eileen M. Uchitelle to Rails core. Eileen has worked tirelessly on Rails for three years, and just completed a major integration bit to have Capybara-backed system tests in Rails 5.1.

Her fingerprints are all over Active Record, she’s been reviewing tons of community pull requests, pushed testing ever forward, and written a bunch of needed documentation. A very well-rounded involvement indeed!

Eileen is Rails core member #14 and our first woman on the team ❤️🎉👏

[ANN] Rails 4.2.8 has been released!

Hi everyone,

I am happy to announce that Rails 4.2.8 has been released.

This is the first version of the 4.2 series that officially support Ruby 2.4.


To view the changes for each gem, please read the changelogs on GitHub:

Full listing

To see the full list of changes, check out all the commits on GitHub.


If you’d like to verify that your gem is the same as the one I’ve uploaded, please use these SHA-1 hashes.

Here are the checksums for 4.2.8:

$ shasum *-4.2.8.gem
cc7ae3c4dcefa6143fab312c0f1f49739665c6d0  actionmailer-4.2.8.gem
185fce7ae0e740dba3282118ab3485a734fbe29b  actionpack-4.2.8.gem
723f43d0d5e07d884fe73241195ede30e63c692a  actionview-4.2.8.gem
5743c76b7ebcb91e93c6ed1af3bf97e5888253fa  activejob-4.2.8.gem
b82e9fe90171934f3fb16b44b6f15abc5e2e942b  activemodel-4.2.8.gem
d794a4c91a5d1eef1dcccb5c8fb2db554e4c2b35  activerecord-4.2.8.gem
7f3383216dd88dd9317447d619a7c671aa362115  activesupport-4.2.8.gem
4e0e486fee35547a7d00f3149634513e8fc2a7e9  rails-4.2.8.gem
ec16b696985663f5e67bbeeb9acf331f3eb3892b  railties-4.2.8.gem

As always, huge thanks to the many contributors who helped with this release.

This Week in Rails: Freeze strings related to caching, query optimization for Postgres and more!

Hey everyone 👋

Prathamesh here with the latest from the world of Rails.

⚡️This week’s Rails contributors ⚡️

This week was full of improvements and bug fixes. We have 24 awesome people contributing to Rails with 3 first-timers!


This change freezes the common strings used for fragment caching reducing the string allocations every time a read/write operation is performed on the fragment cache. The patch showed proper object allocation benchmarks showing a noticeable improvement, so it was accepted.

Optimize query for finding primary keys of a Postgres table

This change simplifies and optimizes the query used to determine the primary keys of a PostgreSQL table improving the overall setup time.


Fix generator command for namespaced Rails engines

This change fixes the default generators to create proper namespaced resources for a namespaced Rails engine. For e.g. if we have a namespaced engine bukkits-admin , then

bin/rails g scaffold User name:string age:integer

will now correctly create


remove_index method can remove expression indexes now

Now, remove_index method can also be used to remove expression indexes apart from simple column indexes.

That’s it from This Week in Rails. There were many other great contributions, too numerous to list here, but feel free to check them out

See ya next week 👣

This Week in Rails: Ruby 2.4 on Rails 4.2

Hello! This is Tim , bringing you another edition of This Week in Rails.

This week’s Rails contributors

This week saw contributions from 26 contributors, including 4 for the first time! What a fantastic bunch!

Rails 4.2.8.rc1 has been released!

If you’re using Rails 4.2, you may want to get a head start by trying out the release candidate for the latest patch release. It’s the first Rails 4 release to support Ruby 2.4, so see if you can give it a try to help us iron out any kinks!


Deprecate locking of dirty records

ActiveRecord::Base#lock! and #with_lock reload the record before doing the actual locking. If there were any unsaved changes, they will be discarded without any warning. When this work is completed in Rails 5.2, an exception will be raised when trying to lock a dirty object. Until then, support for this has been deprecated, so keep an eye out for warnings like these!

Remove support for strings in callback conditions

If you’ve seen deprecation notices concerning strings used in if and unless conditions in callbacks, listen up! Support for these have now been officially removed. Time to update, if you haven’t already!


Allow ActiveRecord::Base.as_json to accept a frozen Hash

As you may know, ActiveRecord::Base.as_json takes an (optional) options hash. That hash is modified internally, but Rails is nice enough to clone it first so that it doesn’t change the thing you passed to it. If your thing was frozen however, it would cause it to blow up! How can this be so, I hear you ask. Well, when you clone an object, you also clone its frozen-ness. dup , on the other hand, does not do this, which turned out to be the solution. Case closed!

That’s it from This Week in Rails. There were many other great contributions, too numerous to list here, but feel free to check them out!

See you next week!

[ANN] Rails 4.2.8.rc1 has been released!

Hi everyone,

I am happy to announce that Rails 4.2.8.rc1 has been released.

If no regressions are found, expect the final release on Wednesday, February 15, 2017. If you find one, please open an issue on GitHub and mention me (@rafaelfranca) on it, so that we can fix it before the final release.


To view the changes for each gem, please read the changelogs on GitHub:

Full listing

To see the full list of changes, check out all the commits on GitHub.


If you’d like to verify that your gem is the same as the one I’ve uploaded, please use these SHA-1 hashes.

Here are the checksums for 4.2.8.rc1:

$ shasum *-4.2.8.rc1.gem
cb6ffe33124a95c84598437c3698f016acc30b01  actionmailer-4.2.8.rc1.gem
ed4c50bf4418ec6b82bf17cf41fcd8dd28a4c423  actionpack-4.2.8.rc1.gem
7ccc80e22af39350f0f2d8055663d1adb2320caa  actionview-4.2.8.rc1.gem
7dc4923abcbf3587c5aa6d6cf425ad0e3f69877e  activejob-4.2.8.rc1.gem
b97863c12a06beca60fe0f1e5760fd2e21f0d40d  activemodel-4.2.8.rc1.gem
40e7d2c780f8b0e70adb2a725fb773648539b4fe  activerecord-4.2.8.rc1.gem
edc12197ae5d6e13d6618c40143196ddd5debadd  activesupport-4.2.8.rc1.gem
04849eea3d5c5f20aa51b6dbd31357c9328d10ab  rails-4.2.8.rc1.gem
e05dce3a6c14b36b35bf1ea13433677e867602ae  railties-4.2.8.rc1.gem

As always, huge thanks to the many contributors who helped with this release.

This Week in Rails: Fresh code to fight the Winter doldrums

Hello! This is your host Andy, bringing you another edition of This Week in Rails.

I’m in a cold Northern climate ❄️️ and we’re in the middle of Winter right now. To me, it’s the best time of the year to stay inside and dive into some new code. Let’s take a look at some of the latest changes made to Ruby on Rails in the past week.

This Week’s Rails Contributors

We had 31 contributors this week. There are lots of PRs for bug fixes which are nice to see. Many thanks to all of the contributors!


Add warnings option to test runner

This change provides an option to enable Ruby’s warnings in tests.


Refactor Active Record reflections

This PR refactors reflections such that we can iterate over each reflection and ask the reflection object what scopes should be applied to the query we are currently building.

Report the attribute on ActiveRecord::SerializationTypeMismatch

When a ActiveRecord::SerializationTypeMismatch error occurs, we will now know which attribute caused the error.

Simplify query in column_definitions() for Postgres

This patch updates how column_definitions() for Postgres is calculated. The author has a nice usage of the EXPLAIN tool, to show that the new implementation is more efficient.


Reload through_record that has been destroyed

For has_one :through associations, if through_proxy is not reset, setting a new record causes the runtime error Can’t modify frozen hash.

Wrapping up

That’s it from This Week in Rails. There were many other great contributions, too numerous to list here, but feel free to check them out!

Catch you next week!

This Week in Rails: Mailer preprocessing and new ERB handler

Steampunk! It’s all the rage with the kids these days.

Honestly, I was going to work this better into the lead but then I ran out of… ssssstea… 🤓

Anyway friendo! Here’s what Kasper dug up from this week in Rails.

This Week’s Rails Contributors

This week we got 33 committers: welcome or hello again! Either way, you all seem to be on the right track 😉

Action Mailer Preprocessing

Incoming! Mailers can now use params allowing for easier preprocessing with before_action akin to Action Controller. To enable call mailers like this: InvitationMailer.with(invitee: person).account_invitation.deliver_later

See the pull request for a considerable A/B example.

Rails uses Erubi for ERB handling

For many years Rails has used Erubis to handle ERB templates, but it’s been deprecated in favor of Erubi. Being 1/6 shorter to type is far from the only thing Erubi has going for it, so dip into the pull request for the full list 😄

One more thing

Steampunk! It’s hip, it’s wholesome and for the whole family.

Wrapping up

That’s it from This Week in Rails! There were many other great contributions, too numerous to list here, but feel free to check them out!

See ya!

New Action Pack caching gems released

Hi everyone,

I’m happy to announce that new versions of the caching gems extracted from Rails 4.0 have been released.

Action Pack Page Caching (v1.1.0)

CHANGES since 1.0.2

  • Support for Rails 5.0
  • Support for setting page_cache_directory at the controller instance level
  • Support for setting page_cache_directory using a proc, symbol or callable object

To see the full list of changes, check out all the commits on GitHub.


If you’d like to verify that your gem is the same as the one I’ve uploaded, please use this SHA-1 hash.

$ shasum actionpack-page_caching-1.1.0.gem
b9626f7afeb1d69267d1fd6b7255a30be7c33d29  actionpack-page_caching-1.1.0.gem

Action Pack Action Caching (v1.2.0)

CHANGES since 1.1.1

  • Support for Rails 5.0
  • Respect Accept header when caching actions
  • Standardise behavior of options :layout and :cache_path when passed a proc, symbol or callable object

To see the full list of changes, check out all the commits on GitHub.


If you’d like to verify that your gem is the same as the one I’ve uploaded, please use this SHA-1 hash.

$ shasum actionpack-action_caching-1.2.0.gem
308c3acf35c0bdbf15e5c63b64aeda0ec817a269  actionpack-action_caching-1.2.0.gem

Many thanks to the numerous people who have contributed PRs and reported bugs.

This Week in Rails: DB adapters, Git, Action Cable and more!

Hello everyone! This is Roque bringing the latest news from the Rails community.

Remember, today is the last day to submit your RailsConf proposal. You have until 11:59 p.m. MST!

Now, let’s get started!

This Week’s Rails Contributors

This week 33 people contributed to Rails. We also got 4 first time contributors. Welcome aboard folks and keep it going!

SQL Server adapter released for Rails 5

The 5.0.x version of the adapter is only for the latest 5.0 version of Rails. If you need the adapter for an older version of Rails, just install the latest version of the adapter that matches your Rails version (3.2.x to 4.1.x).

Git repo in new Rails projects

New projects will now be generated with a Git repo by default. Please use the option --skip-git if you choose to skip it.

Foreign Key Support for SQLite

Adds foreign key support for SQLite 3.6.19 (or greater) in create statements.


Improve the AS::NumericWithFormat#to_s memory allocation

Thanks to some good profiling, ActiveSupport::NumericWithFormat#to_s should behave better and not allocate too many objects. 🔎


Add channel prefix support to Action Cable Redis adapter

Without channel prefix in Redis, apps using the same Redis server could have their communication compromised. You can now set the option channel_prefix in your cable.yml file. Please check the PR for details.

Make all Rails commands work in engines

The following commands are now working in engines: server, console, dbconsole and runner.

Generate migrations at custom path

New database migrations will be generated at the path set by config.paths["db/migrate"] if the option is defined.

Fix Module#parent_name on a frozen module

The method would throw a runtime error when called for a frozen module.

Wrapping up

That’s it from This Week in Rails! There were many other great contributions, too numerous to list here, but feel free to check them out!

Until next week!