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...

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.

...

Ubuntu 18.04 uses systemd to manage services.

There are basically two commands for listing all services and manipulating the state of a certain service: service and systemctl:

• service manages System V init scripts
• systemctl controls the state of the systemd system and service manager. It is backwards compatible to System V and includes the System V services

Therefore I prefer to use systemctl.

See which services are there

>systemctl list-units -a --type=service
  UNIT                                 LOAD     ...

HTML's <input type="file"> accepts a single file. You can allow multiple files via <input type="file" multiple>.
But sometimes, selecting multiple files is not enough and can be cumbersome for the user. Enter webkitdirectory:

<input type="file" webkitdirectory multiple>

Using webkitdirectory switches the browser's file picker to select a directory. All files inside that directory, and inside any nested subdirectories, will be selected for the file input.

This can be useful when users want to upload all files from a nested dire...

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...
   

If you're experiencing problems with your Google Chrome installation after an update, it might help downgrading Chrome to check if the problem disappears. Keep in mind though that running outdated software, especially web browsers, is in most cases not a good idea. Please verify periodically if you still need to run the old version or if an even more recently updated version fixes the problems introduced in your version.

Here's how to get old versions of Chrome for your Ubuntu installation:

First, go to [UbuntuUpdates](https://www.ubuntuup...

On some of our older projects, we use the mysql2 gem. Unfortunately, versions 0.2.x (required for Rails 2.3) and versions 0.3.x (required for Rails 3.2) can no longer be installed on Ubuntu 20.04. Trying this either leads to errors when compiling the native extension, or a segfaults when using it.

For Rails 4.2, mysql2 version 0.4.10 seems to work okay. If you still have issues, upgrade to 0.5.x, which should be compatible.

To install it, you have to switch the mysql2 gem to our fork. In your Gemfile, ...

If you need to test interaction with a remote API, check out the VCR gem as an alternative to Webmock or stubbing hell.

The idea behind VCR is that is performs real HTTP requests and logs the interaction in a .yml file. When you run the test again, requests and responses are stubbed from the log and the test can run offline.

It's a great way to mock network requests to an external service without going through the pain of log...

Fix: downgrade net-ssh to version 2.9.1.

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 ...

It sometimes happen that a database dump, that would want to insert into your development database, does not match the current schema of the database. This often happens when you have an old dump, but your current setup is up to date with the the master.

Hint: In most cases it is sufficient to delete and recreate the local database in order to import the dump. If any problems occur, proceed as follows:

1. Figure out the original migration status of the dumpfile

• Convert your dump to plaintext: `pg_restore -f some.dump > some.dump....

Find conditions for scopes can be given either as an array (:conditions => ['state = ?', 'draft']) or a hash (:conditions => { 'state' => 'draft' }). The later is nicer to read, but has horrible security implications in some versions of Ruby on Rails.

Affected versions

.desktop files define launchers for applications installed on your machine. They specify the command that will be executed when launched, icons, titles, etc. There are two directories in which these files are stored:

# basic installation
/usr/share/applications

# installed via snap
/var/lib/snapd/desktop/applications/

The sidekiq-rate-limiter gem allows rate-limiting Sidekiq jobs and works like a charm. However, it needs to be integrated on a per-worker basis.

If you want to limit a whole queue instead, and if your requirements are simple enough, you can do it via a Sidekiq middleware yourself.

Here is an example that limits concurrency of the "mailers" queue to 1. It uses a database mutex via the [with_advisory_lock](https://github.com/ClosureTree/wit...

Generated Photos produces AI-generated face images.

This is useful for UI mockups where you don't want to show real people or copyrighted stock photography.

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 ...

If a model inherits from others or uses many concerns / traits, it might be hard to see in the code which validators it has.
But fortunately there's a method for that:

irb(main):002:0> pp UserGroup.validators
[#<ActiveModel::Validations::InclusionValidator:0x00007f55efff97a8
  @attributes=[:deleted],
  @delimiter=[true, false],
  @options={:in=>[true, false], :allow_nil=>false}>,
 #<ActiveModel::Validations::InclusionValidator:0x00007f55f15748d0
  @attributes=[:cancelled],
  @delimiter=[true, false],
  @options={:in=>[true, false], ...

Good reference how to build bootstrap forms with simple_form.

When logging in Rails, you can use the log_tags configuration option to add extra information to each line, like :request_id or :subdomain. However, those are only valid inside a request context and have no effect when your application is logging from inside a Sidekiq process.
This includes custom as well as any framework logs, like query logging from ActiveRecord.

Since Sidekiq Workers run inside threads of a single process, running multiple jobs in...

Pagy is a gem for pagination.
They make some bold claims:

Pagy is the ultimate pagination gem that outperforms the others in each and every benchmark and comparison.

Maybe this is worth trying out.

ActiveRecord provides the ids method to pluck ids from a scope, but what if you need to pluck Global IDs?

While you could just call map(&:to_global_id) on your scope, this approach would instantiate each record just to do that. When you have many records, this will at the very least be slow.

Here is a method that does it for you efficiently. It respects Single Table Inheritance (STI).
Put it in your project's ApplicationRecord to make it available on all models.

class ApplicationRecord
  ...

Development

Google Chrome disables Notifications for insecure origins (i.e. those using HTTP). Only http://localhost is considered secure.

If you need to use browser notifications on other origins, you can set a flag: chrome://flags/#unsafely-treat-insecure-origin-as-secure. Enable the flag and add your origins. Remember that "origin" refers to the combination of protocol+hostname+port, e.g. "http://example.com:8088".