Managing Rails locale files with i18n-tasks
When internationalizing your Rails app, you'll be replacing strings like 'Please enter your name'
with t('.name_prompt')
. You will be adding keys to your config/locales/*.yml
files over and over again. Not to miss any key and place each at the right place is a challenging task.
The gem i18n-tasks
has you covered. See its README for a list of things it will do for you.
Note
The
i18n-tasks
gem does not understand aliases and will duplicate all referenced data when it writes locales. If yo...
Running "bundle update" without arguments might break your application
Calling bundle update
(without arguments) updates all your gems at once. Given that many gems don't care about stable APIs, this might break your application in a million ways.
To stay sane, update your gems using the applicable way below:
Projects in active development
Update the entire bundle regularily (e.g. once a week). This ensures that your libraries are up-to-date while it's easy to spot major version bumps which may break the app.
Projects that have not been updated in a while
- [Update a single gem conservatively](htt...
Slack integration for deployments via Capistrano
You can hook into Slack when using Capistrano for deployment. The slackistrano gem does most of the heavy lifting for you. Its default messages are unobtrusive and can be adjusted easily.
When deploying, it posts to a Slack channel like this:
How to integrate
Integrating Slackistrano with Capistrano 3 is fairly simple.
- In your Slack, open menu → A...
Setup Sidekiq and Redis
If you want Sidekiq to be able to talk to Redis on staging and production servers, you need to add the following to your configuration:
# config/initializers/sidekiq.rb
require 'sidekiq'
Sidekiq.configure_client do |config|
config.redis = { url: REDIS_URL }
end
Sidekiq.configure_server do |config|
config.redis = { url: REDIS_URL }
end
The following step may be skipped for new Sidekiq 6+, since it isn't recommended anymore to use a global redis client.
# config/initializers/redis.rb
require 'redis'
require_relativ...
Ruby bug: Symbolized Strings Break Keyword Arguments in Ruby 2.2
TL;DR Under certain circumstances, dynamically defined symbols may break keyword arguments in Ruby 2.2. This was fixed in Ruby 2.2.3 and 2.3.
Specifically, when …
- there is a method with several keyword arguments and a double-splat argument (e.g.
def m(foo: 'bar, option: 'will be lost', **further_options)
) - there is a dynamically created
Symbol
(e.g.'culprit'.to_sym
) that is created before the method is parsed - the method gets called with both the
option
and aculprit
keyword argument
… then the `optio...
Specify Gemfile for bundle
Bundler allows you to specify the name of the Gemfile you want to bundle with the BUNDLE_GEMFILE
environment variable.
BUNDLE_GEMFILE=Gemfile.rails.7.2 bundle
By default, bundler will look for a file called Gemfile
in your project, but there may be cases where you want to have multiple Gemfiles in your project, which cannot all be named Gemfile
. Let's say for example, you maintain a gem and want to run automated tests against multiple rails versions. When you need to bundle one of your secondary Gemfiles, the solution above ...
Using before(:context) / before(:all) in RSpec will cause you lots of trouble unless you know what you are doing
TL;DR Avoid before(:context)
(formerly before(:all)
), use before(:example)
(formerly before(:each)
) instead.
If you do use before(:context)
, you need to know what you are doing and take care of any cleanup yourself.
Why?
Understand this:
-
before(:context)
is run when thecontext
/describe
block begins, -
before(:context)
is run outside of transactions, so data created here will bleed into other specs -
before(:example)
is run before each spec inside it,
Generally, you'll want a clean setup for each s...
Capistrano 3: Running a command on all servers
This Capistrano task runs a command on all servers.
bundle exec cap production app:run cmd='zgrep -P "..." RAILS_ROOT/log/production.log'
Code
# lib/capistrano/tasks/app.rake
namespace :app do
# Use e.g. to grep logs on all servers:
# b cap production app:run_cmd cmd='zgrep -P "..." RAILS_ROOT/log/production.log'
#
# * Use RAILS_ROOT as a placeholder for the remote Rails root directory.
# * Append ` || test $? =1;` to grep calls in order to avoid exit code 1 (= "nothing found")
# * To be able to process ...
Aruba: Stubbing binaries
When testing your command line application with Aruba, you might need to stub out other binaries you don't want to be invoked by your test.
Aruba Doubles is a library that was built for this purpose. It is not actively maintained, but works with the little fix below.
Installation
Install the gem as instructed by its README, then put this Before
block somewhere into features/support
:
Before do
Arub...
Configuring Webpacker deployments with Capistrano
When deploying a Rails application that is using Webpacker and Capistrano, there are a few configuration tweaks that optimize the experience.
Using capistrano-rails
capistrano-rails is a Gem that adds Rails specifics to Capistrano, i.e. support for Bundler, assets, and migrations. While it is designed for Asset Pipeline (Sprockets) assets, it can easily be configured for Webpacker. This brings these features to the Webpacker world:
- Automatic removal of expired assets
- Manifest backups
When does Webpacker compile?
Webpack builds can take a long time, so we only want to compile when needed.
This card shows what will cause Webpacker (the Rails/Webpack integration) to compile your assets.
When you run a dev server
While development it is recommended to boot a webpack dev server using bin/webpack-dev-server
.
The dev server compiles once when booted. When you access your page on localhost
before the initial compilation, the page may load without assets.
The ...
Mailcatcher: An alternative to inaction_mailer
Looks simpler than inaction_mailer:
gem install mailcatcher
mailcatcher
Setup Rails to send mails to 127.0.0.1:1025. Usually you want the following config in config/environments/development.rb
and maybe in test.rb
or cucumber.rb
.
config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
:address => 'localhost',
:port => 1025
}
Now you can see sent mails in your browser when opening http://127.0.0.1:1080
Note: In order to s...
Spreewald, Cucumber: Selector for the nth element
The recommended additional setup of the spreewald gem, a useful set of cucumber steps, includes adding a file for defining custom selectors which can be used as prose within steps:
When I follow "Edit" within the controls section
Where the controls section
can be any arbitrary defined css selector within selectors.rb
Often it can be useful to select the nth element of a specific selector. Luckily, this can ...
makandra/gemika: Helpers for testing Ruby gems
We have released a new library Gemika to help test a gem against multiple versions of Ruby, gem dependencies and database types.
Here's what Gemika can give your test's development setup (all features are opt-in):
- Test one codebase against multiple sets of gem dependency sets (e.g. Rails 4.2, Rails 5.0).
- Test one codebase against multiple Ruby versions (e.g. Ruby 2.1.8, Ruby 2.3.1).
- Test one codebase against multiple database types (currently MySQL or PostgreSQL).
- Compute a matrix of all possib...
Five years of "Today I Learned" from Josh Branchaud
The linked GitHub repository is a bit like our "dev" cards deck, but groomed from a single person (Josh Branchaud). It includes an extensive list of over 900 TILs on many topics that might be interesting for most of us. (e.g. Ruby, Rails, Git, Unix..)
Ruby
Here is an excerpt of all the Ruby TILs that were new to me. I encourage you to take your time to skim over the original list as well!
-
Assoc For Hashes
- `Hash#ass...
Ruby: Comparing a string or regex with another string
In Rubocop you might notice the cop Style/CaseEquality
for e.g. this example:
def foo(expected, actual)
expected === actual
end
In case expected
is a Regex, it suggests to change it to the following pattern:
def foo(expected, actual)
expected.match?(actual)
end
In case expected
is a Regex or a String, you need to keep ===
. Otherwise the actual
expression is always converted to a regular expression.
# For expected === actual
foo('Test(s)', 'Test(s)') #=> true
# For expected.match?(actual)
foo('Test(...
Jasmine: Testing AJAX calls that manipulate the DOM
Here is a Javascript function reloadUsers()
that fetches a HTML snippet from the server using AJAX and replaces the current .users
container in the DOM:
window.reloadUsers = ->
$.get('/users').then (html) ->
$('.users').html(html)
Testing this simple function poses a number of challenges:
- It only works if there is a
<div class="users">...</div>
container in the current DOM. Obviously the Jasmine spec runner has no such container. - The code requests
/users
and we want to prevent network interaction in our uni...
Testing focus/blur events with Cucumber
This is a problem when using Selenium with Firefox. We recommend using ChromeDriver for your Selenium tests.
This setup allows to test focus/blur events in Cucumber tests (using Selenium). For background information, see How to solve Selenium focus issues.
Cucumber step definition:
# This step is needed because in Selenium tests, blur events are not triggered
# when the browser has no focus.
When /^I unfocus the "(.*?)" field to trigger ja...
esbuild: Make your Rails application show build errors
Building application assets with esbuild is the new way to do it, and it's great, especially in combination with Sprockets (or Propshaft on Rails 7).
You might be missing some convenience features, though.
Here we cover one specific issue:
Once you have started your development Rails server and esbuild with the --watch
option (if you used jsbundling-rails to set up, you probably use bin/dev
), esbuild will recompile your assets upon change, but build errors will only be printed to the terminal. Your application won't complain about them ...
Rspec 3: what to do when `describe` is undefined
When tests might not run with skipping RSpec
in the RSpec.describe
failing with the error undefined method 'describe' for main:Object
this card will help you out!
In RSpec 3 the DSL like describe
is exposed globally by default. Therefore it is not necessary to write Rspec.describe
.
However, there is a config option to disable this beavior, which also disables the old should
-syntax:
RSpec.configure do |config|
config.disable_monkey_patching!...
Good real world example for form models / presenters in Rails
We have often felt the pain where our models need to serve too many masters. E.g. we are adding a lot of logic and callbacks for a particular form screen, but then the model becomes a pain in tests, where all those callbacks just get in the way. Or we have different forms for the same model but they need to behave very differently (e.g. admin user form vs. public sign up form).
There are many approaches that promise help. They have many names: DCI, presenters, exhibits, form models, view models, etc.
Unfortunately most of these approaches ...
Postgres in Alpine docker container: sorting order might differ
In CI test runs I noticed that string sorting order changed after switching from a debian-based PostgreSQL docker image to one that is based on Alpine Linux.
Debian image sorting: bar Bar foo Foo
Alpine image sorting: Bar Foo bar foo
Explanation
Alpine Linux is a very slim linux distribution that results in small docker image sizes (roughly 100MB instead of 150MB), so it's a popular choice. However, it does not have all comman locales installed and does not use all locales that a user installs by default.
Postgres orders string co...
Spreewald: Content-Disposition not set when testing a download's filename
Precondition
- You are not using javascript tests
- The file is served from a public folder (not via controller)
Problem description
If you deliver files from a public folder it might be that the Content-Disposition
header is not set. That's why the following spreewald step might raise an error:
Then I should get a download with filename "..."
expected: /filename="some.pdf"$/
got: nil (using =~) (RSpec::Expectations::ExpectationNotMetError)
Solution
One solution...
git: find the version of a gem that releases a certain commit
Sometimes I ran across a GitHub merge request of a gem where it was not completely obvious in which version the change was released. This might be the case for a bugfix PR that you want to add to your project.
Git can help you to find the next git tag that was set in the branch. This usually has the name of the version in it (as the rake release
task automatically creates a git tag during release).
git name-rev --tags <commit ref>
Note
The more commonly used
git describe
command will return the last tag before a c...