By activating strict_loading you force developers to address n+1 queries by preloading all associations used in the index view. Using an association that is not preloaded will raise an ActiveRecord::StrictLoadingViolationError.

I think it's a good default to activate strict_loading in your controllers' #index actions. This way, when a change introduces an n+1 query, you...

Use rules to include or exclude jobs in pipelines.

Rules are evaluated in order until the first match. When a match is found, the job is either included or excluded from the pipeline, depending on the configuration. The job can also have certain attributes added to it.

rules replaces only/except and they can’t be used together in the same job. If you configure one job to use both keywords, the linter returns a key may not be used with rules error.

GitLab 12.3 introduced rules. You can use them in your .gitlab-ci.yml in your proj...

The Truemail gem (not to be confused with truemail.io) allows validating email addresses, e.g. when users enter them into a sign-up form. It runs inside your application and does not depend on an external SaaS service.

Truemail supports different validation "layers":

1. Regex validation: if the given address is syntactically valid
2. DNS validation (called MX validation): if the given domain exists and can receive email
3. SMTP validation: connects to the host received from DNS and starts a test d...

In the Gitlab settings the flag Auto-cancel redundant pipelines is enabled by default. This auto-cancels jobs that have the interruptible setting set to true (defaults to false e.g. to not cancel deploys by accident).

Consider to set the interruptible flag for test jobs to reduce the load on your runners like in the following example .gitlab-ci.yml:

rubocop:
  interruptible: true
  script:
    - 'bundle exec rubocop'

rspec:
  int...

Applications often show or hide elements based on viewport dimensions, or may have components that behave differently (like mobile vs desktop navigation menus).
Since you want your integration tests to behave consistently, you want to set a specific size for your tests' browser windows.

Using WebDriver options / Chrome device metrics

For Google Chrome, the preferred way is setting "device metrics". This allows you to configure dimensions larger than your display and enable/disable touch behavior.

Simply use register_driver to set up...

If you need a sample video with certain properties for a test you can create one using ffmpeg.
You might want a very low bitrate file to speed up processing in your test. (e.g. you only care about the length, then you can create a video with a very low resolution and framerate)

Create a 21s video with 1fps and 10x10 resolution:
ffmpeg -t 21 -s 10x10 -r 1 -f rawvideo -pix_fmt rgb24 -i /dev/zero sample_21_seconds.mp4

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...

This release adds asynchronous compilers and many other features requested by the community.
We also fixed a number of performance regressions introduced by Unpoly 3.11.

Breaking changes are marked with a ⚠️ emoji and polyfilled by unpoly-migrate.js.

Asynchronous compilers

Compiler functions can now be [async](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/...

ActiveRecord computes table names of model classes, and results are usually just like you'd expect.
Adding a prefix for all classes in a namespace can feel a odd or broken, but does not have to be. It's actually very easy when done right.

Summary (tl;dr)

Here's the short version: Define a table_name_prefix method in the namespace module, and do not define any table_name_prefix in ActiveRecord classes inside of it. If this sounds familiar, we have [a card about using it already](https://makandracards.com/makandra/47198-rails-namespac...

Rails has always included a scaffold script that generates a default controller implementation for you. Unfortunately that generated controller is unnecessarily verbose.

When we take over Rails projects from other teams, we often find that controllers are the unloved child, where annoying glue code has been paved over and over again, negotiating between request and model using implicit and convoluted protocols.

We prefer a different approach. We believe that among all the classes in a Rails project, controllers are some of the hardest to...

We use the whenever gem to automatically update the crontab of the servers we deploy to. By default, whenever will update all servers with a matching role (we use the :cron role ).

This card describes how to install some tasks only for a given Rails environment or for a given Capistrano stage ("deployment target").

Installing jobs only for a given Rails environment
-----------------------------------...

You can use git worktree to manage multiple working trees attached to the same repository. But why should I use git worktree?

You can use more than one working tree to ...

... run tests while working on another branch
... compare multiple versions
... work on a different branch without disturbing your current branch

Creating a new working tree is as simple as creating a new branch. You only need to execute git worktree add <path> <branch>. When you are done, you can remove the working tree with git worktree remove <Worktree>...

Capybara has a variety of finder methods like find_button to help you look up DOM elements. There are also matchers like have_field to make expectations during tests.

These methods also have a number of options to influence the lookup. E.g. the :disabled option lets you control whether Capybara will match disabled fields.

If you have a matching condition that cannot be expressed by the existing Capybara opt...

We are using Spring in our tests for sequential test execution but not for parallel test execution. And Rails requires you to set the config.cache_classes = false if you are using Spring in tests.

With our setup, this would raise the following error in cucumber-rails for parallel test executions due to some legacy database cleaner issue.

WARNING: You have set Rails' config.cache_classes to false
    (Spring needs cache_classes set to false). This is known to cause probl...

Native promises have no methods to inspect their state.

You can use the promiseState function below to check whether a promise is fulfilled, rejected or still pending:

promiseState(promise, function(state) {
  // `state` now either "pending", "fulfilled" or "rejected"
});

Note that the callback passed to promiseState will be called asynchronously in the next [microtask](https://jakearchibald.com/2015/tasks-microtasks-queues-and-schedules/...

Option 0: Download from the official page (preferred)

• Open https://googlechromelabs.github.io/chrome-for-testing/
• In Section "Stable" > chromedriver / linux64 > Download ZIP from URL
• Take the chromedriver binary from the ZIP file and put it e.g. into ~/bin.

Chromedriver must be available in your path. You can add ~/bin to your path like this:

echo "export PATH=$PATH:$HOME/bin" >> $HOME/.bash_profile

If you're also using Geordi, disable automatic updating of chromedriver in ~/.config/geordi/global.yml:

a...

Due to the way we setup Jasmine tests in our projects, you may run into various errors when Jasmine boots.

Setting jasmineRequire on undefined

Jasmine 4 may fail with an error like this:

Uncaught TypeError: Cannot set properties of undefined (setting 'jasmineRequire')

This is due to issues in Jasmine's [environment detection](https://github.com/jasmine/jasmine/blob/502cb24bb89212917a3c943b593fd918ffc481cb/lib/jasmine-core/...

The problem

Calling bundle update GEMNAME will update a lot more gems than you think. E.g. when you do this:

bundle update cucumber-rails

... you might think this will only update cucumber-rails. But it actually updates cucumber-rails and all of its dependencies. This will explode in your face when one of these dependencies release a new version with breaking API changes. Which is all the time.

In the example above updating cucumber-rails will give you Capybara 2.0 (because capybara is a dependency of `cucumber-rail...

General

A general overview about why and how we migrate can be found under Migrating from Elasticsearch to Opensearch

This card deals with specifics concerning the use of searchkick.

Step 1: Make Opensearch available for Searchkick

In your Gemfile

# Search
gem 'searchkick'                   # needs to be > 5, to use Opensearch 2
gem 'elasticsearch'
gem 'opensearch-ruby'

in config/initializers/searchkick.rb (or wherever you have configured your Searchkick settings) add:

SEARCHKICK_CLIENT_T...

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...

Safari on iOS accepts an apple-touch-icon favicon that is used for stuff like desktop bookmarks. Always define a solid background color for them.

If you use PNGs with a transparent background, Safari will use just set a black background on your pretty icon. This is almost never what you want.
You can fix that by applying a white background via ImageMagick like this:

convert a...

You can use ETags to allow clients to use cached responses, if your application would send the same contents as before.

Besides what "actually" defines your response's contents, your application probably also considers "global" conditions, like which user is signed in:

class ApplicationController < ActionController::Base

  etag { current_user&.id }
  etag { current_user&.updated_at }

end

Under the hood, Rails generates an ETag header value like W/"f14ce3710a2a3187802cadc7e0c8ea99". In doing so, all objects from that etagge...

RubyMine has a HTTP Client that can be useful to test web APIs.
Just create a .http scratch file an write your request in it.
The request can then be executed with the "Run all requests in File" button above the file.

Some alternatives:

• Postman
• Curl

The format for request is like this:

Method Request-URI HTTP-Version
Header-field: Heade...

Spreewald comes with a selector_for helper that matches an English term like the user's profile into a CSS selector. This is useful for steps that refer to a particular section of the page, like the following:

Then I should see "Bruce" within the user's profile
                                 ^^^^^^^^^^^^^^^^^^

If you're too lazy to manually translate English to a CSS selector by adding a line to features/env/selectors.rb, we already have an [auto-mapper to translate English into ...