In order to avoid rare loading differences between Test and Production, we like to set config.cache_classes = true in config/environments/test.rb. However, the new "zeitwerk" autoloader in Rails 6 has issues with this setting when Spring is used. It cannot reload properly and will fail with:

reloading is disabled because config.cache_classes is true

Interestingly, classes were already unloaded beforehand, so the next invocation of e.g. bin/rake db:migrate RAILS_ENV=test will run successfully. Still, this needs to be fixed.

##...

calc() lets you mix CSS units. Ever wanted to give an element "the container's width minus 20px on each side"? Here you go:

width: calc(100% - (20px * 2));

When using Sass, you need to interpolate Sass expressions:

width: calc(100% - #{$margin})

Supported by all modern browsers and IE9+.

In JavaScript we often use Immediately Invoked Function Expessions (or IIFEs) to prevent local variables from bleeding into an outside scope:

(function() {
  var foo = "value"; // foo is scoped to this IIFE
})();

In Coffeescript an IIFE looks like this:

(->
  foo = "value" # foo is scoped to this IIFE
)()

There is also a shorthand syntax with do:

do ->
  foo = "value" # foo is scoped to this IIFE

You can also use do with arguments t...

In Rubocop you might notice the cop Style/CaseEquality for e.g. this example:

def foo(expected, actual)
  expected === actual
end

In case expected is a Regex, it suggests to change it to the following pattern:

def foo(expected, actual)
  expected.match?(actual)
end

In case expected is a Regex or a String, you need to keep ===. Otherwise the actual expression is always converted to a regular expression.

# For expected === actual
foo('Test(s)', 'Test(s)') #=> true

# For expected.match?(actual)
foo('Test(...

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.

...

For outputting a given String in HTML, you mostly want to replace line breaks with <br> or <p> tags.
You can use simple_format, but it has side effects like keeping some HTML.

If you only care about line breaks, you might be better off using a small, specialized helper method:

def format_linebreaks(text)
  safe_text = h(text)
  paragraphs = split_paragraphs(safe_text).map(&:html_safe)

  html = ''.html_safe
  paragraphs.each do |paragraph|
    html << content_tag(:p, paragraph)
  end

...

capybara_element['attribute_name'] allows accessing an element's attributes in Capybara.

A few examples:

find('#my_element')['class']
# => "first-class second-class"

find('#my_input')['placeholder']
# => "My placeholder value"

find('a#example-link')['href']
# => "http://example.com"

find('#my_element')['missing_attribute']
# => nil

In a project team for a bigger project people have several roles:

• Developer: at makandra
• Project lead: at makandra
• Project manager (PM): at makandra, external, or with the customer. In a smaller project this person is also the project lead.
• Product owner (PO): with the customer

Developer

• Development
• Take responsibility for their stories. This includes always gathering all necessary information from the project lead or the PM, communicate blockers, make sure stories are merged, deployed etc.
• Tell the project lead, if you'r...

Rails does not offer a "vanilla" way of negating an ActiveRecord scope. Here are two ways to do it yourself without too much effort.

Example:

class User
  scope :admins, -> { where(role: ['admin', 'superuser'] }
  # ...
end

Now what if we want a scope of users that are not admins? While you could declare a second scope like scope :non_admins, -> { where(role: ['guest', 'editor']) }, there are ways to use the opposite of the admins scope.

Option A: Subquery

You could just use a subquery. Doing that with scopes is easy...

Ubuntu 18.04 uses systemd to manage services.

See which Services are running

To get an overview which services are available and running / not running, you can use service --status-all:

>service --status-all
 [ + ]  acpid
 [ - ]  alsa-utils
 [ - ]  anacron
 [ + ]  apache-htcacheclean
 [ - ]  apache2
 [ + ]  apparmor
 [ + ]  apport
 [ + ]  avahi-daemon
 [ + ]  avahi-dnsconfd
 [ - ]  bluetooth
 [ - ]  bootmisc.sh
 [ - ]  brltty
...

+ means running, - means not running, ? means unknown

Manage Services

To temporaril...

Geordi provides a pretty neat way to generate beautiful commit messages according to your stories in Pivotal Tracker:

geordi commit

Geordi reads from a .geordi.yml file inside your repo and connects to Pivotal Tracker to list started and finished stories with their title. Choosing one of them generates a commit message including id and title from pivotal tracker. For example:

[#1234567] CRUD Users

Trouble shooting

If you encounter a bug like `40...

When accepting GIF images, you will also accept animated GIFs. Resizing them can be a time-consuming task and will block a Rails worker until the image is processed.

Save yourself that trouble, and simply tell ImageMagick to drop any frames but the first one.

Add the following to your uploader class:

process :remove_animation

private

def remove_animation
  if content_type == 'image/gif'
    manipulate! { |image| image.collapse! }
  end
end

You may also define that process for specific versions only (e....