Rails developers: Have better context in Git diffs

Git diffs show the surrounding contexts for diff hunks. It does so by applying regular expressions to find the beginning of a context. When it comes to Ruby, however, it will not find method heads and travel up to the class definition:

@@ -24,7 +24,7 @@ class TicketPdf # <=== Actually expected here: the method definition
     ApplicationController.render(
       "tickets/index.html.haml",
       layout: "tickets",
-      assigns: { tickets: tickets }
+      assigns: { tickets: tickets, event_name: event_name }
     )
   end
 end
```...

Show/Hide Rubocop marking in RubyMine

If you have installed Rubocop in your project, RubyMine can show you Rubocop violations immediately in your editor. You probably already know this feature.

Example

Image

Enable/Disable marking

If your RubyMine does not show you any violations, although there are some, you may have to enable the setting first.

To do so, open Navigate -> Search Everywhere -> Actions (Or use the shortcut CTRL + SHIFT + A) and type in "rubocop", then you should see some...

Terminator: do not broadcast to other windows

Terminator has a cool feature that allows you to split your terminal into many panels and type in all of them at the same time. It's called broadcasting and can be enabled by pressing Alt+a (and disabled by Alt+o).

However, in some circumstances it will also be broadcasted to other running instances of Terminator. This probably is not what you want and could be very dangerous (e.g. if you're logged in to a production server in a terminal that is on another workspace).

To prevent the broadcast from affecting other windows, go to `Prefer...

Passive event listeners may speed up your scroll and touch events

Scroll and touch event listeners tend to be computationally expensive as they are triggered very often. Every time the event is fired, the browser needs to wait for the event to be processed before continuing - the event could prevent the default behavior. Luckily there is a concept called passive event listeners which is supported by all modern browsers.

Below are the key parts quoted from WICG's explainer on passive event listeners. See [this demo video](https://www.youtube.com/watch?v=NPM6172...

Ruby: A short summary of available hooks in Cucumber

Here is a short summary of Cucumber hooks in Ruby taken from https://github.com/cucumber/cucumber-ruby. Note that the BeforeStep is currently not existing in the Ruby implementation of Cucumber.

Before hooks run before the first step of each scenario.

Before do |scenario|
  ...
end

After hooks run after the last step of each scenario, even when the step result is failed, undefined, pending or skipped.

...

Migrate gem tests from Travis CI to Github Actions with gemika

We currently test most of our gems on Travis CI, but want to migrate those tests to Github Actions. This is a step-by-step guide on how to do this.

Note that this guide requires the gem to use gemika.

  1. Go to a new "ci" branch:
    git checkout -b ci
    
  2. Update gemika to version >= 0.5.0 in all your Gemfiles.
  3. Have gemika generate a Github Actions workflow definition by running
    mkdir -p .github/workflows; bundle exec rake gemika:generate_github_actions_workflow > .github/workf...
    

PostgreSQL: Importing dumps created with newer versions

When loading a database dump created with pg_dump into your database, you might run into an error like

pg_restore: error: unsupported version (1.15) in file header

This is because your local pg_restore version is too old to match the format created by pg_dump. The version of the PostgreSQL server doesn't matter here.

For example, the official Ubuntu 20.04 sources include only PostgreSQL 12, so your pg_restore version will also be v12. Ubuntu 22.04 includes version 14 in its sources.
Both seem to be incompatible with dumps ...

VCR and the webdrivers gem

If you're using the webdrivers gem and VCR together, depending on your configuration, VCR will yell at you regulary.
The webdrivers gem tries to update your webdrivers on your local machine. To do so, it checks the internet for newer versions, firing an HTTP-request to e.g. https://chromedriver.storage.googleapis.com

You can "fix" this in multiple ways:

  1. Update your drivers on your machine with
    RAILS_ENV=test rake webdrivers:chromedriver:update

  2. Ignore the driver update-URL in your ...

Carrierwave: How to migrate to another folder structure

A flat folder structure can be cool if you have only a few folders but can be painful for huge amounts. We recently had this issue in a project with more than 100.000 attachments, where we used a structure like this /attachments/123456789/file.pdf.

Even the ls command lasted several minutes to show us the content of the attachments folder.

So we decided to use a more hierarchical structure with a limited maximum of folder per layer. Here are a few tips how to migrate your files to their new...

Cucumber 4 and VCR integration

If you are trying to integrate VCR and Cucumber 4 and you're using the use_scenario_name: true option you will run into an error like this:

undefined method `feature' for #<Cucumber::RunningTestCase::TestCase:0x00005650550ba080>

Currently the VCR integration and Cucumber 4 is broken, but you can find an open issue with details and a monkey patch here.

Controlling issue grouping in Sentry

When you use Sentry to monitor exceptions, an important feature is Sentry's error grouping mechanism. It will aggregate similar error "events" into one issue, so you can track and monitor it more easily. Grouping is especially important when you try to silence certain errors.

It is worth understanding how Sentry's grouping mechanism works.

The default grouping mechanism

The exact algorithm has changed over time, and Sentry will keep using the algorithm t...

Git: How to stage hunks with a single key press

In interactive commands, Git allows the user to provide one-letter input with a single key without hitting enter (docs).

# Enabled this feature globally
git config --global interactive.singlekey true

# Or enable this feature locally for a single repository
git config interactive.singlekey true

This allows you to hit "y" instead of "y + ENTER" to move to the next hunk.

Stage this hunk [y,n,q,a,d,s,e,?]?

Parallel cucumber: How to pass in cucumber arguments

Here is an example with the --tags option. You need to wrap them inside --cucumber-options option of parallel_cucumber.

DISPLAY=:17 bundle exec parallel_cucumber --cucumber-options '--tags @solo' features

See more details in the docs.

Useful Ruby Pathname method

If you have a Ruby Pathname, you can use the method :/ to append filepaths to it.

With this method, Ruby code can look like this:

Rails.root/"features"/"fixtures"/"picture.jpg"

Alternatively you can use the #join method, which feels less magic:

Rails.root.join('features', 'fixtures', 'picture.jpg')

The State of Ruby 3 Typing | Square Corner Blog

We're pleased to announce Ruby 3’s new language for type signatures, RBS. One of the long-stated goals for Ruby 3 has been to add type checking tooling. After much discussion with Matz and the Ruby committer team, we decided to take the incremental step of adding a foundational type signature language called “RBS,” which will ship with Ruby 3 along with signatures for the stdlib. RBS command line tooling will also ship with Ruby 3, so you can generate signatures for your own Ruby code.

Ruby 3 is coming, and it will have optional type sign...

Introducing GoodJob 1.0, a new Postgres-based, multithreaded, ActiveJob backend for Ruby on Rails

GoodJob is a new background worker gem. It's compatible with ActiveJob.

We're huge fans of Sidekiq for its stability and features. One advantage of GoodJob over Sidekiq is that GoodJob doesn't require Redis. So in cases where you don't have Redis or don't want to pay for a Redis HA quorum node, this might be an alternative worth checking out.

Sentry: Different ways of deferring notifications for an issue

We use Sentry to be informed about different kinds of issues. One of the key features is that you are not getting spammed if many errors of the same kind occur in a small timespan.
If an issue pops up the usual workflow is to fix the code and mark the issue as "resolved" in Sentry. Only new or resolved issues trigger another email notification when they are proxied through Sentry.

This workflow does not fit well for issues we cannot fix, e.g. when consuming an external API that is sometimes down. In such cases you ...

Automatically validating dependency licenses with License Finder

"Open-source software (OSS) is great. Anyone can use virtually any open-source code in their projects."

Well, it depends. Licenses can make things difficult, especially when you are developing closed-source software. Since some OSS licenses even require the employing application to be open-sourced as well (looking at you, GPL), you cannot use such software in a closed-source project.

To be sure on this, we have developed a project-level integration of Pivotal's excellent [license_finder](https:/...

FactoryBot: Traits for enums

FactoryBot allows to create traits from Enums since version 6.0.0

The automatic definition of traits for Active Record enum attributes is enabled by default, for non-Active Record enums you can use the traits_for_enum method.

Example

factory :user do
  traits_for_enum :role, %w[admin contact] # you can use User::ROLES here, of course
end

is equivalent to

factory :user do
  trait :admin do
    role { 'admin' }
  end

  trait :contact do
    role { 'c...

Select2 alternatives without jQuery

Select2 is a fantastic library for advanced dropdown boxes, but it depends on jQuery.

Alternatives

Tom Select

There is a selectize.js fork called Tom Select. It is well tested, comes with Bootstrap 3, Bootstrap 4 and Bootstrap 5 styles and is easy to use. You might miss some advanced features.

Known issues:

  • Dynamic opt-groups in AJAX requests are not supported, you need to define them in advance on the select field (see <https://github.com/selectize/selectize.js/pull/1226/...

Howto: Select2 with AJAX

Select2 comes with AJAX support built in, using jQuery's AJAX methods.
...
For remote data sources only, Select2 does not create a new element until the item has been selected for the first time. This is done for performance reasons. Once an has been created, it will remain in the DOM even if the selection is later changed.

If you have a huge collection of records for your select2 input, you can populate it via AJAX in order to not pollute your HTML with lots of <option> elements.

All you have to do is to provide...

The JavaScript Object Model: Prototypes and properties

Speaker today is Henning Koch, Head of Development at makandra.

This talk will be in German with English slides.

Introduction

As web developers we work with JavaScript every day, even when our backend code uses another language. While we've become quite adept with JavaScript at a basic level, I think many of us lack a deep understanding of the JavaScript object model and its capabilities.

Some of the questions we will answer in this talk:

  • How does the new keyword construct an object?
  • What is the differen...

Cucumber may complain about cucumber.yml being invalid when it is valid

Running Cucumber tests while your cucumber.yml is 100% valid may still produce the following error.

cucumber.yml was found, but could not be parsed. Please refer to cucumber's documentation on correct profile usage.

This may in fact be due to your rerun file (e.g. tmp/rerun.txt) being invalid. Delete it and try again.

Legacy CarrierWave: How to generate versions with different file extensions

We use CarrierWave in many of our projects to store and serve files of various formats - mostly images. A common use case of CarrierWave's DSL is to "process" the original file in order to create multiple "versions", for example different resolutions of the same image.

Now we could go one step further: What if we want to create versions that have a different file extension than the original file? For example, let's assume we'd like to create a ve...