What I Learned from Short Ruby Newsletter (#129)

I subscribed to the Short Ruby Newsletter a long time ago. I love it because it contains tons of interesting examples of Ruby and Ruby on Rails code that I would want to use in my apps. In every edition, I read about so many things which are new to me and might be useful.

Sadly, I always read the newsletter but never remember or use the cool new things. However, I decided to make a change, I took notes of the things that I found interesting and were new to me and thought I would write a small summary.

Here’s what I learned in #129:

Hotwire cheatsheet

Igor Kasyanchuk published a hotwire cheatsheet which will come in handy everytime I want to glance and quickly find something out about hotwire.

Custom Rails Constraints

This great article talks about using contraints to route webhooks sent from slack to proper controller actions. Using this approach you don’t have to conditionally check in the controller what type of webhook event you’ve got and then route it to the proper action.

Rails.application.routes.draw do
  post '/slack/events', 
    to: 'slack/messages#received',
    constraints: EventsConstraint['message']
  
  post '/slack/events',
    to: 'slack/messages#mentioned',
    constraints: EventsConstraint['app_mention']
  
  post '/slack/events',
    to: 'slack/home#opened',
    constraints: EventsConstraint['app_home_opened']
  
  post '/slack/events', 
    to: 'slack#events' # catch-all for remaining events
end

Above he draws the same route four times /slack/events but according to what event_type the webhook contains, the request is routed to the proper controller.

For constraints to work, all you need is a matches? method that returns true or false. docs

Did you know that rails provides subdomain constraints by default?

get "photos", to: "photos#index", constraints: { subdomain: "admin" }

# The above will route admin.example.com/photos to Photos#index

I didn’t!

ActionMailer::Base#email_address_with_name

There’s an email_address_with_name helper which returns an email address in the format of <Some Name> <email address>

We were using these kind of addresses in many parts of the codebase I work on and so I was able to refactor that into using this method.

Use bundler inline for quick scripts

I have seen this used in many bug recreation scripts in the Rails repo but never realized it was this simple.

require 'bundler/inline'

gemfile do
  source "https://rubygems.org/"
  gem "paint"
end

puts Paint['Ruby', :red] 
#=> prints Ruby in red color

Multiple Gemfiles

I hadn’t realized that I could use multiple Gemfiles in the same repo. This seems useful.

# Gemfile

gem ...
gem ...

if File.exist?('Gemfile.local')
  puts "\n>> Installing local development specified gems..."
  system("bundle check --gemfile=Gemfile.local || bundle install --jobs=4 --gemfile=Gemfile.local")
end

# Gemfile.local

source "https://rubygems.org"

gem "paint"

This will create a new Gemfile.local.lock file that tracks the gem versions installed via the Gemfile.local file.

I’m hugely grateful to the Short Ruby Newsletter team for curating these incredibly useful tips and tricks. My biggest lesson is learning about using Custom Routing Constraints and I can’t wait to triage my codebase to look for places I can use it!