All browsers + IE9 know the CSS :empty selector. It lets you hide an element when it has no content, i.e. not even white space.

(How to prevent whitespace in HAML)

For instance, you have a badge displaying the number of unread messages in a red bubble with white text:

.unread-messages-bubble {
  background-color: red;
  border-radius: 10px;
  padding: 10px;
  color: white;
}

To hide that bubble entirely ...

The linked article provides a description of commonly found problems with TLS and hints on debugging / solving them.

tl;dr: Avoid to memoize methods with default (keyword) arguments!

When you are using Memoized with default arguments or default keyword arguments, there are some edge cased you have to
keep in mind.

When you memoize a method with (keyword) arguments that have an expression as default value, you should be aware
that the expression is evaluated only once.

memoize def print_time(time = Time.now)
  time
end

print_time
=> 2021-07-23 14:23:18 +0200

sleep(1.minute)
print_time
=> 2021-07-23 14:23:18 +0200

When you memoize a met...

We had a card that described how to install multiple mysql versions using mysql-sandbox. Nowadays with the wide adoption of docker it might be easier to use a MySQL docker image for this purpose.

Create a new mysql instance

docker run --name projectname_db -e MYSQL_ROOT_PASSWORD=secret -p "33008:3306" -d --restart unless-stopped mysql:5.7

The port 33008 is a freely chosen free port on the host machine that will be used to establish a...

The rubygems binary gem allows to extract a local gem with gem unpack GEMNAME. For more details see the official documentation.

This was useful for compliance checks, when it was necessary to check the license of the C-files in nokogiri.

If your Carrierwave uploader dynamically generates the filename (e.g. by incorporating a user's name), you must call model.save! after recreating versions.

uploader.recreate_versions! does not update the model with the stored filename.

better_errors is an awesome gem for enhanced error pages in development, featuring a live-REPL for some light debugging.

To debug the exception you got on an AJAX-Request, visit /__better_errors on your app's root path (e.g. http://localhost:3000/__better_errors). It shows the error page for the last exception that occurred, even when it has been triggered by an AJAX request.

You can scale background images in CSS to the container size using background-size (Demo).

Commonly, we use contain or cover because we want to preserve the image's aspect ratio.
If you do not want to do that, simply provide scaling values for X and Y:

background-size: 100% 100%

(a simple 100% would mean 100% auto and respect the image's aspect ratio)

SVGs with a viewBox will force their aspect ratio

The above may not work for you when ...

All Rubyists should be familiar with the common definitions for include and extend. You include a module to add instance methods to a class and extend to add class methods. Unfortunately, this common definition isn’t entirely accurate. It fails to explain why we use instance.extend(Module) to add methods to an instance. Shouldn’t it be instance.include(Module)? To figure this out we’re going to start by discussing where methods are stored.

• include: Adds methods from the provided Module to the object
• extend: Calls include on the single...

When using custom properties in your stylesheets, you may want to set a specific property value to an existing variable in your SASS environment. A pratical example would be a list of color variables that you've defined in colors.sass and that you would like to refer to in your stylesheets. However, simply assigning a variable will not work:

$my-great-blue: blue

:root
  --my-color: $my-great-blue

.sky
  background-color: var(--my-color)

The property value will not be valid and if you open the browser's inspection window, yo...

It seems like changing the HTTP_ACCEPT_LANGUAGE is not possible for a headless chrome.

• On Ubuntu the headless Chrome derives the Accept-Language from the operation system
• Adding the option options.add_argument('--lang=de') to the Capybara::Selenium::Driver has no effect
• Adding the preference options.add_preference('intl.accept_languages', 'de') to the Capybara::Selenium::Driver has only effects if the --headless option is skipped (see bug ticket #775911)
• Cha...

You can throttle the network in your headless chrome via Selenium. This might be useful for debugging issues with flaky integration tests or slow page simulations.

page.driver.browser.network_conditions = {offline: false, latency: 5, download_throughput: 2 * 1024, upload_throughput: 2 * 1024}

The settings will match to the following UI component in Chrome:

Were the values for the default profiles might match the values from this post:

**S...

An extensive list of command line options when booting Chrome.

This is useful for building a Capybara driver with custom Chrome options.

I ran into a situation in which I received the yarn integrity check warning when starting the rails console even though everything was up to date and correct versions in use.

TLDR: run spring stop

I tried starting the rails console without switching to the correct node version first and received the yarn integrity warning.

warning Integrity check: System parameters don't match                                                                                     
error Integrity check failed                                         ...

Starting with Ruby 2.0 you can define methods with keyword arguments.

In 2.1+ required keyword arguments can be defined by using a colon without default value:

def match(value, ignore:)
  # ...
end

To accomplish something similar in ruby 1.8, use:

def match(value, options = {})
  ignore = options.fetch(:ignore)
  # ...
end

When using RestClient to make an HTTP request, it will raise an exception when receiving a non-successful response.
HTTP status codes like 422 or 403 might be totally expected when talking to APIs, so plastering your code with rescue RestClient::Exception or similar can feel annoying.

It may not be intuitive, but the readme says you can also pass a block to methods like RestClient.get or RestClient::Request.execute. In that case, RestClient will not raise ...

Der verlinkte Artikel grenzt präzise ab, welche Aufgaben zur Suchmaschinenoptimierung (SEO) gehören und welche nicht.

Suchmaschinenoptimierung ist eine Querschnittsfunktion: die Arbeit vieler unterschiedlicher Abteilungen hat Einfluss auf den SEO-Erfolg der Firma. In diesem Beitrag versuchen wir deswegen, den Kern von SEO zu definieren.

To start a workflow manually it must have a trigger called workflow_dispatch:

---
name: Tests
on:
  push:
    branches:
    - master
  pull_request:
    branches:
    - master
  workflow_dispatch:
    branches:
    - master  

In the Actions tab of your repo you can now select a workflow and press "Run Workflow".

See GitHub documentation for details.

If you have a flaky command you can use the nick-invision/retry to re-try a failing command, optionally with a timeout:

---
...
jobs:
  test:
    ...
    steps:
    - name: Run tests
      uses: nick-invision/retry@v2
      with:
        timeout_seconds: 30
        max_attempts: 3
        command: bundle exec rake spec

The attached patch lets you find a record by a string or number in any column:

User.find_by_anything('carla')
User.find_by_anything('email@domain.de')
User.find_by_anything(10023)

There's also a bang variant that raises ActiveRecord::NotFound if no record matches the given value:

User.find_by_anything!('carla')

Boolean and binary columns are excluded from the search because that would be crazy.

I recommend copying the attachment to features/support/find_by_anything.rb, since it is most useful in Cucumber step def...

If you want to find the commits that touched a specific text in a file, use

git log -S 'text in the code' -- path/to/file

If you use tig you may run a similar command to get a navigatable list of affected files:

tig -S'text in the code'

Example

Here is an example, where the move of the convert_number_column_value(value) method in active record is traced (simplified output):

git log -n 1 --pretty=oneline -S 'convert_number_column_value(value)' -- activerecord/lib/active_record/base.rb
ceb33f84933639d3b6...