Enumerable#count can do three things.

• With no argument provided, it returns the number of items.
• With an argument, it returns the number of items matching the given value.
• With a block, it counts the number of elements yielding a truthy value.

ary = [1, 2, 4, 2]
ary.count #=> 4
ary.count(2) #=> 2
ary.count { |x| x % 2 == 0 } #=> 3

Array#flatten by default flattens an array recursively. To only flatten the array for e.g. one level, it takes an optional argument.

# Flattens the array recursively
>> [1, [2, [3]]].flatten
=> [1, 2, 3]

# Flattens the array the given number of times
>> [1, [2, [3]]].flatten(1)
=> [1, 2, [3]]

I got the following error after updating the selenium-webdriver gem:

wrong number of arguments (0 for 1) (ArgumentError)
/home/pointoo-dev/.rvm/gems/ruby-1.8.7-p374/gems/selenium-webdriver-2.35.1/lib/selenium/webdriver/common/platform.rb:183:in `open'
/home/pointoo-dev/.rvm/gems/ruby-1.8.7-p374/gems/selenium-webdriver-2.35.1/lib/selenium/webdriver/common/platform.rb:183:in `ip'
/home/pointoo-dev/.rvm/gems/ruby-1.8.7-p374/gems/selenium-webdriver-2.35.1/lib/selenium/webdriver/common/platform.rb:196:in `interfaces'

It was caused...

Gem to show failing specs instantly.
Unlike the --fail-fast option it doesn't abort abort on the first failure, but keeps running other examples after print out the failure.

I haven't tried it with parallel_tests.

The Javascript in operator does what Hash#has_key? does in Ruby: Return whether an object has a property.
However, Coffeescript has its own in operator that checks for array inclusion. To check whether an object has a property, use of:

Javascript

'name' in {name: 'Horst'} # => true

Coffeescript

# wrong
'name' in {name: 'Horst'} # => false

# correct
'name' of {name: 'Horst'} # => true
1 in [1,2,3] # => true

True story.

To find a hash key by it's value, i.e. reverse lookup, one can use Hash#key. It's available in Ruby 1.9+.

Hash#key(value) → key
# => Returns the key of the first occurrence of a given value.
     If the value is not found, returns nil.

hash = { "a" => 100, "b" => 200, "c" => 300, "d" => 300 }
hash.key(200)   #=> "b"
hash.key(300)   #=> "c"
hash.key(999)   #=> nil

With ActiveSupport you can say:

class Robot
  def self.likes_humans?
    'Nope.'
  end

  delegate :likes_humans?, to: :class
end

Robot.likes_humans?
# => 'Nope.'

Robot.new.likes_humans?
# => 'Nope.'

Preview what your markdown would look like on Github. Helpful e.g. when writing or extending a Readme for your gem or projects.

Installation

sudo apt-get install cmake libicu-dev # required for building native extensions
gem install octodown

Know that this will install at least 12 other gems. However, the beautiful output should be worth it.

Usage

octodown README.md

Add gem 'database_cleaner' to your Gemfile. Then:

Cucumber & Rails 3+

# features/support/database_cleaner.rb

DatabaseCleaner.clean_with(:deletion) # clean once, now
DatabaseCleaner.strategy = :transaction
Cucumber::Rails::Database.javascript_strategy = :deletion

Cucumber & Rails 2

The latest available cucumber-rails for Rails 2 automatically uses database_cleaner when cucumber/rails/active_record is required -- but only if transactional fixtures are off. To have database_cleaner work correctly:

1. Add the ...

When a gem author releases a new version to Rubygems, usually a tag with the version number (e.g. v1.2.0) is created an pushed to Github, so everyone can check out or take a look at the source code at this point version release at a later time.

If you'd like to take a look at the Readme of a specific Gem version, you can easily switch to that git tag on Github.

Jonas Nicklas, the author of Carrierwave and Capybara, has released Refile, a gem for handling file uploads in Rails. It handles direct uploads (also direct uploads to Amazon S3) better than Carrierwave.

The story and reasoning behind some of the decisions in Refile, and how it's different from Carrierwave, by the author himself, is a good read before deciding which way you'll go.

Big Caveat: Refile only stores the original image and r...

Make sure you have libcurl3-dev installed:

sudo apt-get install libcurl3-dev
gem install typhoeus

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 [...

Databound provides Javascript a simple API to the Ruby on Rails CRUD.

Tries to expose a full model CRUD as an API. Not sure if this is useful for more refined requirements.

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.

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...

Traveling Ruby is a project which supplies self-contained, "portable" Ruby binaries: Ruby binaries that can run on any Linux distribution and any OS X machine. This allows Ruby app developers to bundle these binaries with their Ruby app, so that they can distribute a single package to end users, without needing end users to first install Ruby or gems.

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...

Shortener is a Rails Engine Gem that makes it easy to create and interpret shortened URLs on your own domain from within your Rails application. Once installed Shortener will generate, store URLS and “unshorten” shortened URLs for your applications visitors, all whilst collecting basic usage metrics.

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...

For our production servers we use Passenger as a Ruby application server. While it is possible to use Passenger for development as an Apache module, the installation process is not for the faint of heart.

Luckily Passenger also comes as a standalone binary which requires zero configuration.

You can Passenger Standalone as a replacement for Webrick or Thin if you'd like to:

• Use SSL certificates locally
• Get performance behavior that is closer to ...

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...

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
---------...