Capybara-screenshot can automatically save screenshots and the HTML for failed Capybara tests in Cucumber, RSpec or Minitest.

Requires Capybara-Webkit, Selenium or poltergeist for making screenshots. Screenshots are saved into $APPLICATION_ROOT/tmp/capybara.

Manually saving a page

Additionally you can trigger the same behavior manually from the test using Capybara::Session#save_and_open_page and [...

Rails includes a way to see what an e-mail will look like.

Integration to RSpec

All you need to do is implement a preview-class in spec/mailers/previews/notifier_preview.rb:

class NotifierPreview < ActionMailer::Preview
  def welcome
    Notifier.welcome(User.first)
  end
end

And adapt the preview load path in your application.rb:

config.action_mailer.preview_path = "#{Rails.root}/spec/mailers/previews" # For Rails < 7.1
config.action_mailer.preview_paths << "#{Rails.root}/spec/mailers/previews" # For Rails >=...

You can do so much more than console.log(...)! See the attached link for a great breakdown of what the developer console can give you.

Some of my favorites:

console.log takes many arguments

E.g. console.log("Current string:", string, "Current number:", 12)

Your output can have hyperlinks to Javascript objects

E.g. console.log("Check out the current %o, it's great", location)

[Di...

Rails guide that covers PostgreSQL-specific column types and usages for Active Record.

You should especially keep in mind the special datatypes that PostgreSQL offers. \
Types like json and array take away a lot of the pain that you had on MySQL projects.

Example use cases for array are tags or storing foreign keys (instead of a join model). You can even index them.

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

Cucumber will clean up files you've uploaded in your Cucumber features automatically with the attached code. Put the file in features/support/.

RSpec::Matchers.define :be_naturally_sorted do
  match do |array|
    array == array.natural_sort
  end
end

See RSpec: Where to put custom matchers and other support code. To use natural_sort, see this card.

This matcher is now part of Spreewald.

This step will pass if the specified select is sorted.

Then /^the "(.*?)" select should be sorted$/ do |label, negate|
  select = find_field(label)
  options = select.all('option').reject { |o| o.value.nil? }

  options.collect(&:text).each_cons(2) do |a,b|
    (a.text.downcase <=> b.text.downcase).should <= 0
  end
end

In conjunction with this custom matcher, the each_cons block can be replaced with:

options.should be_naturally_sorted

Usage

Then the "Organizations" select should be sorted...

Chances are you're seeing the warning repeated a lot of times, maybe thousands of times. Here's how to reproduce the issue:

Example 1

# bad code
(Time.current .. Time.current + 1.hour).include?(Time.current)

# Use Range#cover? instead of Range#include? since the former does no typecasting into integers.
(Time.current .. Time.current + 1.hour).cover?(Time.current)

Example 2

# bad code
Post.where(:created_at => min_date.beginning_of_day .. max_date.end_of_day)

# Use 'BETWEEN x AND y'
Post.where(['posts.created_at BETWEEN...

Sometimes you want Angular to watch an object only until a certain state is reached (e.g. an object appears in the scope).

Angular's $watch returns a method that you can call to remove that watch. For example:

unwatch = $scope.$watch 'user', (user) ->
  if user?
    ... # do something
    unwatch()

That's it.

Copy data from LibreOffice Calc

When you copy data from multi-line cells in LibreOffice Calc, quotation marks are automatically added, which you may not want.

For example with license keys:

09:46:24 [✔] pascal:~> icdiff license license_copy 
license                           license_copy                           
===== LICENSE BEGIN =====         "===== LICENSE BEGIN =====             
00000yIeXfhGSbt"yULWQR9n          00000yIeXfhGSbt""yULWQR9n        
olysFAv105bHmKOiqbxRX"Yr  ...

The Rails asset pipeline improves delivery of application assets (javascripts, stylesheets, images, fonts). Here are some basic facts about its inner workings.

No magic

Manifests are the handle on your assets:

app/assets/stylesheets/application.css # use via: stylesheet_link_tag 'application'

The asset pipeline only considers files you explicitly require within your manifest files. The most common directives used in manifests are require some/file and require_tree some/directory. Paths may be **relative to the current director...

When you run code inside a $watch expression that forces a repaint (e.g. by computing an element's width, or running something like element.is(':visible')) you may end up with "page flickering" or scroll offset changes.

You can hook to the end of a digest cycle to avoid that.

The following is basically straight from the docs, but pretty awkward to use. Do it...

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...

If you get one of this errors:

Error: Could not retrieve catalog from remote server: Error 400 on SERVER: (<unknown>): found character that cannot start any token while scanning for the next token at line 1297 column 3
Warning: Not using cache on failed catalog
Error: Could not retrieve catalog; skipping run

Error: Could not retrieve catalog from remote server: Error 400 on SERVER: undefined method `empty?' for nil:NilClass at /etc/puppet/environments/production/manifests/nodes.pp:1 on node example.makandra.de
Warning: ...

When putting phone numbers into web pages, you should use tel: links so smartphone users can click those numbers to call someone.

Here is a small helper method that you can use to simplify this:

def tel_to(text)
  groups = text.to_s.scan(/(?:^\+)?\d+/)
  link_to text, "tel:#{groups.join '-'}"
end

This will allow you to use human-readable numbers and get clean links:

>> tel_to '(01234) 555 6789'
=> <a href="tel:01234-555-6789">(01234) 555 6789</a>

>> tel_to '+1 555 123-456'
=> <a href="tel:+1-555-123-456...

Raphaël is a small JavaScript library that should simplify your work with vector graphics on the web. If you want to create your own specific chart or image crop and rotate widget, for example, you can achieve it simply and easily with this library.

Upgrading from Ruby 1.8.7 to 2.1.2 took me an hour for a medium-sized application. It involved hardly any changes except

• removing the occasional monkey patch where I had backported functionality from modern Rubies
• Migrating from require to require_relative where I loaded RSpec factories in Cucumber's env.rb (the Rails application root is no longer in the load path by default)
• replacing the old debugger with byebug
• removing sytem_timer from Gemfile (see [this SO thread](http://stackoverflow.com/questions/7850216/how-to-inst...

Cucumber allows for prose in features and scenarios. Example:

Feature: Cancel account

  There are several ways to cancel a user account. Admins need to 
  do it in complex cases, but normally, users can do it themselves.
  
  Scenario: User cancels his own account
    
    Users should be able to cancel an account themselves, so the 
    admins do not need to do it.
    
    Given a user account for "willy@astor.de"
    When I sign in as "willy@astor.de"
    And I follow "Cancel account"
    Then I should see "Account canceled"...

If you make a gem with Bundler, you will get a rake release task that will instantly publish your gem to rubygems.org for all the world to admire. For private gems this is very bad.

To make sure this cannot happen, rubygems 2.2+ allows you to restrict eligible push hosts:

Gem::Specification.new 'my_gem', '1.0' do |s|
  # ...
  s.metadata['allowed_push_host'] = 'https://gems.my-company.example'
end

In case you already messed up, [follow these instructions to get your gem removed](http://help.rubygems.org/kb/rubygems/removing-an-a...

This is a problem when using Selenium with Firefox. We recommend using ChromeDriver for your Selenium tests.

Firefox will not trigger focus/blur events when its window is not focused. While this makes sense in standard usage, it breaks in parallel test execution.

Please do not rely on focus events in your tests. The linked card has an example of how to build passing tests that deal with focus/blur events.

Using this gem I could get JSON generation from a large, nested Ruby hash down from 200ms to 2ms.

Its behavior differs from the default JSON.dump or to_json behavior in that it serializes Ruby symbols as ":symbol", and that it doesn't like an ActiveSupport::HasWithIndifferentAccess.

There are also some issues if you are on Rails < 4.1 and want it to replace #to_json (but you can always just call Oj.dump explicitely).

Security warning: Oj does not escape HTML entities in JSON
---------...