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...

Installing gems on a server that has no access to the internet (especially rubygems.org) requires to bundle the gems into the repository itself. This requires to adjust the bundle config in the repository.

1. Execute the following commands to configure bundler:

bundle config set --local path vendor
bundle config set --local disable_shared_gems true

Note

For Bundler < 2 you have to omit the "set": bundle config --local name value.
See here: [https://bundler.io/v1.17/man/bundle-config.1.html](https://bundler.io/v1.17/man...

Generate a password

htpasswd -Bn firstname.lastname

This will ask you for a password and use bcrypt (-B, more secure) and print the output to stdout (-n).

Check if password matches the hash

You'll first have to write the password hash to a file:

echo firstname.lastname:$2y$05$4JXxd2GM/J2...9c3KJmFS > htpass_test

Check, if it is correct:

htpasswd -v htpass_test firstname.lastname

You probably should not use the -b switch to read the password from the command line as the password will then be visible...

When you need the DOM node of a <script> tag (e.g. to read extra attributes, or to modify the DOM near it), you can usually reference it via document.currentScript.
However, document.currentScript is unsupported in ancient browsers, like Internet Explorer 11 or wkhtmltopdf's Webkit engine.

If you are not running async scripts, you can easily polyfill it:

document.scripts[document.scripts.length - 1]

It works because document.scripts grows with each <script> tag that was evaluated.
That is also the reason why th...

In newer passenger versions the output of passenger -v has changed. capistrano-passenger tries to parse the version and now causes the error undefined method '[]' for nil:NilClass. To fix this you only need to upgrade the capistrano-passenger gem.

Therefore run bundle update capistrano-passenger --conservative.

The version change of passenger from 6.0.7 to 6.0.8 has triggered this problem. This is fixed in capistrano-passenger >= 0.2.1.

ActiveRecord offers an explain method similar to using EXPLAIN SQL statements on the database.

However, this approach will explain all queries for the given scope which may include joins or includes.

Output will resemble your database's EXPLAIN style. For example, it looks like this on MySQL:

User.where(id: 1).includes(:articles).explain

EXPLAIN for: SELECT `users`.* FROM `users`  WHERE `users`.`id` = 1
+----+-------------+-------+-------+---------------+
| id | select_type | table | type  | possible_keys |
+----+-----...

I use the TypeScript compiler for this, since its output is more minimal than Babel's.

The following will transpile all src/*.js files into a file build.js:

npm install typescript
npx tsc src/*.js --target ES5 --allowJs --outFile build.js

The output will only transpile ES6 syntax. It will not include any polyfills for missing APIs.

I really love to use the shortcuts CTRL+Alt+ Arrow Left and CTRL+Alt+ Arrow Right to navigate through the code. It worked great on Ubuntu 18.04 and MATE but after migrating to my new notebook with GNOME and Ubuntu 20.04, I realized that the shortcuts didn't work anymore. Well, it worked via Navigate > Back and also showed the shortcut, but my fingers weren't able to do this...

I cried a lot. (Why God? WHY?)

Then I found this [thread on StackOverflow](https://stackoverflow.com/questions/47808160/intellij-idea-ctrlaltleft-short...

When you have a hex color code, you can easily convert it into its RGB values using plain Ruby.

>> "#ff8000".match(/^#(..)(..)(..)$/).captures.map(&:hex)
=> [255, 128, 0]

You can use that to implement a simple "hex to CSS rgba value with given opacity" method:

def hex_color_to_rgba(hex, opacity)
  rgb = hex.match(/^#(..)(..)(..)$/).captures.map(&:hex)
  "rgba(#{rgb.join(", ")}, #{opacity})"
end

>> hex_color_to_rgba("#ff8000", 0.5)
=> "rgba(255, 128, 0, 0.5)"

If you need to support RGBA hex color codes,...

Starting from Rails 4.0, you can use a special form options helper called #collection_check_boxes. It behaves similar to #collection_select, but instead of a single select field it renders a checkbox and a label for each item in the collection.

= form_for @post do |form|
  = form.collection_check_boxes :author_ids, Author.all, :id, :name_with_initial

How generated form params look like
---------------------------------...

https://tableconvert.com/ is an online tool to convert tables between different formats (e.g. json, markdown, csv).
It also has a button to transpose a table ("rotate" it by 90 degree).

The tool can be handy if you have tests with large markdown tables for testing contents of a flat json structure or csv.

Please note that you should not use it with sensitive data (like all online tools in general).

We prefer to run our end-to-end tests with headless Chrome. While it's a very stable solution overall, we sometimes see the headless Chrome process freeze (or the Capybara driver losing connection, we're not sure).

The effect is that your test suite suddenly stops progressing without an error. You will eventually see an error after a long timeout but until then it will seem that your suite is frozen. If you're also using [capybara-screenshot](https:/...

Browsers blocks abusable JavaScript API calls until the user has interacted with the document. Examples would be opening new tab or start playing video or audio.

E.g. if you attempt to call video.play() in a test, the call will reject with a message like this:

NotAllowedError: play() failed because the user didn't interact with the document first. https://goo.gl/xX8pDD

Workaround

To pretend document interaction in a test you can create an element, click on it, and remove the element again. This unblocks the entire JavaSc...

The ActionDispatch module of Rails gives you the helper method flash to access the flash messages in a response.

describe PostsController, type: :request do

  describe 'update' do

    it 'shows a success message on update' do
      post_record = create(:post)

      put "/posts/#{post_record.id}"

      # Same as @request.flash[:alert]
      expect(flash[:alert]).to eq('Post updated successfully.')
    end

  end


end

capybara-lockstep can help you with flaky end-to-end tests:

This Ruby gem synchronizes Capybara commands with client-side JavaScript and AJAX requests. This greatly improves the stability of a full-stack integration test suite, even if that suite has timing issues.

5.4.0 2021-02-01

Compatible changes

• Add geordi branch command that checks out a feature branch based on a story from Pivotal Tracker
• Faster MySQL dumping with --single-transaction and --quick
• Allow pivotal tracker ids in the global config file
• Fix missing require for Fileutils in the dump load command (#145)
• Document PARALLEL_TEST_PROCESSORS

The linked article shows that there are unclear parts in the JSON specification and that different parsers treat them differently (which could lead to security vulnerabilities in certain cases).

I was curious what Ruby does (Ruby 2.6.6 with gem json 2.3.0, implementing RFC 7159):

Duplicate Keys

irb(main):001:0> require 'json'
=> true
irb(main):002:0> JSON.parse('{"qty": 1, "qty": -1}')
=> {"qty"=>-1}

Character Collision

irb(main):009:0> JSON.parse('{"qty": 1, "qty\ud800": -1}')
JSON::ParserError (487: incomplete sur...

We had the issue, that a VCR spec failed, after updating CarrierWave from version 0.11.0 to 1.3.2.
In this version, CarrierWave uses the gem SsrfFilter, which retrieves the IP addresses for the given hostname and replaces the hostname in the requested url with one of them.

It works with IPv4 addresses, but not with IPv6 addresses, because WebMock cannot handle those correctly:

uri = "#{protocol}://...

ZSH is an alternative command line shell that includes some features like spelling correction, cd automation, better theme, and plugin support. You can replace Bash with ZSH like following:

sudo apt-get install zsh

Setting ZSH as default login shell

sudo usermod -s /usr/bin/zsh $(whoami)

Opening a new terminal window will show you a dialog where you can configure your initial ZSH config (Option 2 recommended).

Afterwards you can install the plugin manager Oh-My-ZSH and select a prop...

The pages […] allow you to see different types of mixed content and test how they behave in your browser. The "Secure" pages are referencing assets with HTTPS, the "Non-Secure" pages are referencing them with HTTP. Generally, you'll observe the same behavior with both Secure pages and the Secure HTTP page for a given test; the behavior will change on the Non-Secure HTTPS page.

Also see Testing HTTPS with badssl.com.

Sometimes you want to have a time in a given timezone independent from you Rails timezone settings / system timezone. I usually have this use case in tests.

Example

Time.parse('2020-08-09 00:00') will return different results e.g. 2020-08-09 00:00:00 +0200 depending on the Rails timezone settings / system timezone. But in this example we always want to have the given time in UTC because that's what the API returns.

it 'returns a valid API response', vcr: true do
  expect(client.get('/users/1')).to have_attributes(
    name: 'So...

tl;dr: Upgrade the gem to at least 4.0.1

When you use rspec_rails in a version < 4 with Rails 6.1 you may encounter an error like this:

Failure/Error:
  raise WrongScopeError,
    "`#{name}` is not available from within an example (e.g. an " \
    "`it` block) or from constructs that run in the scope of an " \
    "example (e.g. `before`, `let`, etc). It is only available " \
    "on an example group (e.g. a `describe` or `context` block)."
    `name` is not available from within an example (e.g. an `it` block) or from constructs that...

A rough guide how to implement a REST API.

The discussion here includes some interesting points as well:

• Timestamps: ISO8601 format ("2021-02-22T20:34:53.686Z")
• Google API guideline: https://google.aip.dev/
• Numbers: String vs. Number

  The JSON number type is not a double. It's just a number of arbitrary size and precision in integer/decimal/E format that can be parsed as whatever the parser finds fitting.

• Pagination: Limit + Offset vs. Object ID / Pointer vs. System-Version...