Exception notifier: How to provide custom data to fail mails
The exception_notification gem supports to provide custom data to e.g. the fail mail within foreground or background jobs.
ExceptionNotifier.notify_exception(_ex_, :data => {:message => "was doing something wrong"})
Still this can be blocked if you have an initializer where you override the default sections
and background_sections
option. So remember to add the data
option to the desired section if required. In case you raise an exception without a data object, the fail...
Katapult 0.5.0 released
New Features
- Deployment ready for Opscomplete
- Copying view and controller templates over to target application during
basics configuration or via new commandkatapult templates
. - "Usage" section in README rewritten: Now describes two usage scenarios.
Improvements
- Generating a fixed Gemfile.lock. Run
bundle update
after code generation to
update all gems to recent versions. - Better deployment with Webpack
- Navigation only rendered if requested
- Some minor fixes
RubyMine: How to add a german spell checker
Grazie Lite
Rubymine 2024.3 bundles Grazie Lite by default. You need to enabled "German" under Settings/Preferences | Editor | Natural Languages
.
Hunspell (legacy)
- Install the
Hunspell
plugin and restart Ruby Mine - Run
sudo apt install hunspell-de-de
- Select
/usr/share/hunspell/de_DE.dic
in File > Settings > Editor > Spelling > Custom Directory +

It is possible to access Rails config (for example secrets) from within your webpack bundles, thanks to rails-erb-loader. When using webpacker, the setup is like this:
-
Install
rails-erb-loader
:yarn add rails-erb-loader
-
Add this to your
config/webpacker/environment.js
:environment.loaders.prepend('erb', { test: /\.erb$/, enforce: 'pre', use: [{ loader: 'rails-erb-loader', }] })
-
Start using erb. For examp...
How to examine an unknown Ruby object
When debugging your application, you will come across objects created by some gem or framework. You don't have the source code at hand, still need to inspect this object. Here are some tools to do so:
Relevant methods
@object.methods - Object.instance_methods
returns a list of methods excluding methods inherited from Object
. This makes the methods list drastically more relevant. You can also try subtracting other base classes like ActiveRecord::Base.methods
etc.
To further narrow it down you can also just look at public methods...
Rbenv: How to remove a gem installed from a Github source
Normally you can list all gems of the current ruby version with gem list
, which also includes the gems of you Gemfile
. These can be uninstalled with gem uninstall gemname
.
List and uninstall a gem installed via Bundler from Github
This does not work for gems installed directly from Github. They do not appear in gem list
.
Show all gems installed via Github by bundler:
ls ~/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/
Remove a gem installed via Github by Bundler:
rm -rf ~/.rbenv/versions/2.4.1/lib/ruby/gems/2....
How to let passenger restart after deployment with capistrano
Phusion Passenger changed the way how it gets restarted several times. Through the project's history, these all were valid:
touch tmp/restart.txt
sudo passenger-config restart-app /path/to/app
passenger-config restart-app /path/to/app
You should not need to know which one to use. Instead, the capistrano-passenger gem will choose the appropriate restart mechanism automatically based on your installed the passenger version.
Installation
-
Add to your
Gemfile
:gem 'capistr...
An incomplete guide to migrate a Rails application from paperclip to carrierwave
In this example we assume that not only the storage gem changes but also the file structure on disc.
A general approach
Part A: Create a commit which includes a script that allows you to copy the existing file to the new file structure.
Part B: Create a commit which removes all paperclip logic and replace it with the same code you used in the first commit
Part A
Here are some implementation details you might want to reuse:
- Use the existing models to read the files from
- Use your own carrierwave models to write t...
Geordi: How to rerun failed features
Geordi's cucumber
command has a --rerun
option that reruns failing tests the given number of times. Usage:
geordi cucumber path/to/features --rerun=2
geordi cucumber path/to/features -r2
Background and how to rerun manually
Cucumber will save a file tmp/parallel_cucumber_failures.log
containing the filenames and line number of the failed scenarios after a full test run. Normally you can say cucumber -p rerun
(rerun is a profile defined by default in config/cucumber.yml
) to rerun all failed scenarios.
Here are a few al...
Rails < 5: How to get after_commit callbacks fired in tests
If you use transactional_fixtures
or the database_cleaner gem with strategy :transaction
, after_commit
callbacks will not be fired in your tests.
Rails 5+
Rails 5 has a fix for this issue and no further action is needed.
Rails 3, Rails 4
Add the gem test_after_commit to your test
group in the Gemfile and you are done. You don't need to change the database strategy to deletion
(wh...
Ruby: How to use prepend for cleaner monkey patches
Let's say you have a gem which has the following module:
module SuperClient
def self.foo
'Foo'
end
def bar
'Bar'
end
end
For reasons you need to override foo
and bar
.
Keep in mind: Your code quality is getting worse with with each prepend
(other developers are not happy to find many library extensions). Try to avoid it if possible.
- Add a
lib/ext/super_client.rb
to your project (see How to organize monkey patches in Ruby on Rails projects) - Add the extension, which ov...
How to write a good changelog
We want to keep a changelog for all gems we maintain. There are some good practices for writing a changelog that adds value, please stick to these.
- Add a notice to the README's contribute section about the changelog
- For every release update the changelog
- Note the date format yyyy-mm-tt
What is a changelog?
A changelog is a file which contains a curated, chronologically ordered list of notable changes for each version of a project.
Why keep a changelog?
To make it easier for users and...
How to make changes to a Ruby gem (as a Rails developer)
At makandra, we've built a few gems over the years. Some of these are quite popular: spreewald (> 1M downloads), active_type (> 1M downloads), and geordi (> 200k downloads)
Developing a Ruby gem is different from developing Rails applications, with the biggest difference: there is no Rails. This means:
- no defined structure (neither for code nor directories)
- no autoloading of classes, i.e. you need to
require
all files yourself - no
active_support
niceties
Also, their scope...
How to fill in multiple lines in a textarea with cucumber
If you want to fill in textareas with multiple lines of text (containing line breaks / new lines) you can use Cucumber's docstrings:
And I fill in "Comment" with:
"""
This is a long comment.
With multiple lines.
And paragraphs.
"""
The step definition is part of the spreewald gem
Whenever: Don't forget leading zeros for hours!
Whenever is a Ruby gem that provides a nicer syntax for writing and deploying cron jobs.
Leading zeros are important for whenever if you use the 24-hours format!
This schedule.rb
:
every 1.day, at: '3:00', roles: [:primary_cron] do
runner 'Scheduler.delay.do_things'
end
will lead to this crontab entry (crontab -l
) with the default configuration:
0 15 * * * /bin/bash -l -c 'cd /var/www/my-project/releases/20180607182518 && bin/rails runner -e production '\''Scheduler.delay.do_things'\'''
Which would run on 3...
Capistrano + Rails: Tagging production deploys
Just like Ruby Gems tag their version releases to the corresponding Git commit, it can be helpful to track production deploys within the commit history. This task does the tagging for you.
Capistrano 3
# lib/capistrano/tasks/deploy.rb
namespace :deploy do
...
desc 'Tag the deployed revision'
task :tag_revision do
date = Date.today.to_s
puts `git tag deploy-#{date} #{fetch :current_revision}`
puts `git push --tags origin`
end
end
# config/deploy/production.rb
after 'deploy:finished', 'deploy:tag_revi...
Unpoly: Loading large libraries on-demand
When your JavaScript bundle is so massive that you cannot load it all up front, I would recommend to load large libraries from the compilers that need it.
Compilers are also a good place to track whether the library has been loaded before. Note that including same <script>
tag more than once will cause the browser to fetch and execute the script more than once. This can lead to memory leaks or cause duplicate event handlers being registered.
In our work we mostly load all JavaScript up front, since our bundles are small enough. We recent...
Webpacker: Configuring browser compatibility
Webpacker uses Babel and Webpack to transpile modern JavaScript down to EcmaScript 5. Depending on what browser a project needs to support, the final Webpack output needs to be different. E.g. when we need to support IE11 we can rely on fewer JavaScript features. Hence our output will be more verbose than when we only need support modern browsers.
Rails 5.1+ projects often use Webpacker to preconfigure the Webpack pipeline for us. The default configuration works something like this:
- Webpack checks w...
Bundler error: Downloading gem revealed dependencies not in the API
Recent Bundler (1.16.1) started complaining about missing dependencies in the Gemfile. This is due to a stricter handling of specifications (see attached link).
The error message looks like this:
Downloading example-gem-1.2.3 revealed dependencies not in the API or the lockfile (other-gem (< 3)).
Either installing with `--full-index` or running `bundle update example-gem` should fix the problem.
However, bundle install --full-index
did not any better for me, and bundle update
is not always a viable solution.
Easiest solut...
Fixing: Gem::Package::PathError: installing into parent path is not allowed
This might be a known issue with Rubygems 2.5.1. This will help:
gem update --system
Running Rails 2 apps with modern MariaDB SQL server
You might have some trouble running a Rails LTS 2 app with MySQL 5.7.
If you don't want to hack Mysql 5.6 into your modern Ubuntu or use the MySQL sandbox, you might want to try MariaDB 10.x.
MariaDB 10.x should work with both old and new Rails applications.
[Switch to MariaDB](https://makandracards.com/makandra/468343-how-...
Making httpclient use the operating system's SSL cert store
The httpclient gem comes with a custom SSL cert store.
While an customizable, application-level cert store is great when you need to deal with broken or self-signed certificates, you usually want to use the cert store from the underlying Linux. The Linux cert store is updated periodically while httpclient's cert store goes out of date and will eventually not be able to verify certs.
To use the cert store from the underlying operating system:
client = HTTPClient.new
client.ssl_config.cert_store...
Upgrading a Rails app to Cucumber 3
Upgrade gems
You need to update a lof gems. Make sure you don't have any version constraints in your Gemfile
or your bundle update
won't do anything!
Upgrade cucumber_priority
:
bundle update cucumber_priority
Upgrade spreewald
:
bundle update spreewald
Upgrade cucumber_factory
:
bundle update cucumber_factory
Upgrade parallel_tests
:
bundle update parallel_tests
Even on the latest version, parallel_tests
will print some deprecation warnings due to using an older formatter A...