#075 on Rails 6

Running Rails 6, learning about changes and new features, and testing out my favourite gems including: HAML

Notes

Rails 6 was release August 16, 2019.

Major features in Rails 6:

Action Mailbox allows you to route incoming emails to controller-like mailboxes.
Action Text brings rich text content and editing to Rails.
Parallel Testing allows you to parallelize your test suite
Action Cable testing tools allow you to test your Action Cable functionality at any level: connections, channels, broadcasts.

Upgrading to Rails 6.0

Recommended approach for upgrading an existing application:

ensure there is good test coverage
first upgrade to Rails 5.2
check advice in the Upgrading Ruby on Rails guide

Checking Pre-requisites and Installation

$ node -v
v11.10.0
$ npm -v
6.7.0
$ ruby -v
ruby 2.6.0p0 (2018-12-25 revision 66547) [x86_64-darwin17]
$ sqlite3 --version
3.19.3 2017-06-27 16:48:08 2b0954060fe10d6de6d479287dd88890f1bef6cc1beca11bc6cdb79f72e2377b
$ gem install rails -v 6.0.0
...
$ rails --version
Rails 6.0.0

Fixing missing dependencies

Node.js not installed. Please download and install Node.js https://nodejs.org/en/download/

brew install node

Yarn not installed. Please download and install Yarn from https://yarnpkg.com/lang/en/docs/install/

brew install yarn

Could not get it to work with node v12.8.0; had to downgrade to 11.15.0

n 11.15.0

Creating a Simple App

$ rails new minime6
...
$ cd minime6
$ rails db:migrate
$ rails server
=> Booting Puma
=> Rails 6.0.0 application starting in development
=> Run `rails server --help` for more startup options
Puma starting in single mode...
* Version 3.12.1 (ruby 2.6.0-p0), codename: Llamas in Pajamas
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://localhost:3000
Use Ctrl-C to stop

Hit http://localhost:3000..

rails6-hello

Adding a Welcome Page

Using controller generator:

bin/rails generate controller Welcome index

Adjust routes to use this as the main page.

rails6-welcome

Testing

$ rake test
Run options: --seed 13985

# Running:

.

Finished in 4.183906s, 0.2390 runs/s, 0.2390 assertions/s.
1 runs, 1 assertions, 0 failures, 0 errors, 0 skips

Adding The Blog App

The getting started guide has always outlined a simple blog application. Adding the basic features to minime6:

rails generate controller Articles
rails generate model Article title:string text:text
rails db:migrate

Using HAML

I prefer haml for templating in Rails. Does it still work for Rails 6? Yes!

While one can just add the haml gem, I’m using haml-rails which adds a rake task for converting Erb files. I ran this over all files in the app:

$ rails haml:erb2haml
--------------------------------------------------------------------------------
Generating HAML for app/views/articles/index.html.erb...
Generating HAML for app/views/articles/edit.html.erb...
Generating HAML for app/views/articles/show.html.erb...
Generating HAML for app/views/articles/_form.html.erb...
Generating HAML for app/views/articles/new.html.erb...
Generating HAML for app/views/welcome/index.html.erb...
Generating HAML for app/views/layouts/application.html.erb...
Generating HAML for app/views/layouts/mailer.html.erb...
Generating HAML for app/views/layouts/mailer.text.erb...
--------------------------------------------------------------------------------
HAML generated for the following files:
  app/views/articles/index.html.erb
  app/views/articles/edit.html.erb
  app/views/articles/show.html.erb
  app/views/articles/_form.html.erb
  app/views/articles/new.html.erb
  app/views/welcome/index.html.erb
  app/views/layouts/application.html.erb
  app/views/layouts/mailer.html.erb
  app/views/layouts/mailer.text.erb
--------------------------------------------------------------------------------
Would you like to delete the original .erb files? (This is not recommended unless you are under version control.) (y/n)
y
Deleting original .erb files.
--------------------------------------------------------------------------------
Task complete!
No .erb files found. Task will now exit.

Rendering Multiple Formats

Using respond_to

The default Rails mechanism, demonstrated with the Time::NowController.

  def show
    respond_to do |format|
      format.html
      format.json { render json: time_data }
      format.xml { render xml: time_data.to_xml(root: 'time') }
      format.text { render plain: @time }
    end
  end

Generating JSON:

$ curl -H "Accept: application/json" http://localhost:3000/time/now
{"iso8601":"2019-07-24T15:55:40Z"}
$ curl http://localhost:3000/time/now.json
{"iso8601":"2019-07-24T15:56:22Z"}

Generating XML:

$ curl -H "Accept: application/xml" http://localhost:3000/time/now
<?xml version="1.0" encoding="UTF-8"?>
<time>
  <iso8601>2019-07-24T15:56:58Z</iso8601>
</time>
$ curl http://localhost:3000/time/now.xml
<?xml version="1.0" encoding="UTF-8"?>
<time>
  <iso8601>2019-07-24T15:57:07Z</iso8601>
</time>

Generating plain text:

$ curl -H "Accept: text/plain" http://localhost:3000/time/now
2019-07-24T16:06:53Z
$ curl http://localhost:3000/time/now.txt
2019-07-24T16:07:29Z

Rails Controller Testing

rails-controller-testing adds back the assigns and assert_template methods for controller testing (these were removed from rails core in 5.0)

Working in Rails 6 - I’ve added an assert_template 'welcome/index' test.

Credits and References

Rails Getting Started
Rails 6 Timeline
Rails 6 Release Notes
Ruby Versions for Rails
Rails API 6.0.0
HAML
- haml - info
- haml gem source
- haml-rails gem source
Testing Gems
- rails-controller-testing

Project Notes