Use like this:

power-rake db:migrate VERSION=20100913132321

By default the environments development, test, cucumber and performance are considered. The script will not run rake on a production or staging environment.

This script is part of our geordi gem on github.

To only run a single describe/context block in a long spec, you can say

spec spec/models/note_spec.rb:545

... where the describe block starts at line 545.

Note: This will only run examples that are direct children of this block, not descendants further down (when nesting describe/context blocks).

You may also pass the line of an it block to run this exact one.

There are many different methods that allow mapping an Array to a Hash in Ruby.

Array#to_h with a block (Ruby 2.6+)

You can call an array with a block that is called with each element. The block must return a [key, value] tuple.

This is useful if both the hash key and value can be derived from each array element:

users = User.all
user_names_by_id = users.to_h { |user| [user.id, user.name] }

{
  1 => "Alice",
  2 => "Bob"
}

Array#to_h on an array of key/value tuples (Ruby 2.1+)

Converts an Array ...

When submitting textareas, browsers sometimes include carriage returns (\r) instead of just line feeds (\n) at the end of each line. I don't know when this happens, and most of the time it doesn't matter.

In cases where it does matter, use the attached trait to remove carriage returns from one or more attributes like this:

class Note
  does 'strip_carriage_returns', :prose, :code
end

Here is the test that goes with it:

describe Note do

  describe 'before_validation' do...

When a spec only runs when it is called directly, but not as part of the whole test suite, make sure the filename is foo_spec.rb instead of just foo.rb.

By default, Cucumber uses mocha. This note shows to use RSpec stubs and mocks instead.

Rspec 1 / Rails 2

Put the following into your env.rb:

require 'spec/stubs/cucumber'

Rspec 2 / Rails 3

Put the following into your env.rb:

require 'cucumber/rspec/doubles'

Note: Since Cucumber 4 it is important to require these lines in the env.rb and not any other file in support/* to register the hooks after any other After hook in support/*. Otherwise your doubles are removed, while other After steps requi...

There are two distinct ways of commenting Haml markup: HTML and Ruby.

HTML comments

This will create an HTML comment that will be sent to the client (aka browser):

/= link_to 'Example', 'www.example.com'

This produces the following HTML:

<!-- = link_to 'Example', 'www.example.com' -->

Only use this variant if you need the comment to appear in the HTML.

Ruby comments

This will comment code so it will not be sent to the client:

-# = link_to 'foo'

99% of the time you'll be adding notes f...

This is an awesome gadget in your toolbox, even if your test coverage is great.

• gem install ruby-debug (Ruby 1.8) or gem install debugger (Ruby 1.9)
• Start your server with script/server --debugger
• Set a breakpoint by invoking debugger anywhere in your code
• Open your application in the browser and run the code path that crosses the breakpoint
• Once you reach the breakpoint, the page loading will seem to "hang".
• Switch to the shell you started the server with. That shell will be running an irb session where you can step thr...

There will probably be better solutions as we become more experienced with using Bundler, and more command line tools become Bundler-aware.

b will use bundle exec if there is a Gemfile in the working directory, and run the call without Bundler otherwise.

b spec spec

This script is part of our geordi gem on github.

Put

def task_with_hoptoad_notification(options)
  task(options) do
    begin
      yield
    rescue Exception => e
      Airbrake.notify(e)
      raise e
    end
  end
end

at the top of the Rakefile, and replace all relevant

task :my_task => :environment do
    do_something
end

with

task_with_hoptoad_notification :my_task => :environment do
    do_something
end

This will use the usual notification rules, i.e. you won't get anything in the development or test environments.
...

Update RubyGems and Passenger

Bundler requires Rubygems >= 1.3.6. Run gem update --system if you have an older version.
It also is not compatible with older versions of passenger, so bring that up to date as well (2.2.15 works).

If you installed RubyGems through apt (which you should never do!), you may see a message giving you a hint to use apt to update.
Some people advise to install the 'rubygems-update-1.3.7' gem on Ubuntu systems if you used apt to install RubyGems.
I did that - and lost all...

Sometimes you want to fetch associations for an ActiveRecord that you already loaded, e.g. when it has deeply nested associations.

Edge Rider gives your models a static method preload_associations. The method can be used to preload associations for loaded objects like this:

class UsersController < ApplicationController
  def show
    @user = User.find(params[:id])
    @user.preload_associations(threads: { posts: :author }, messages: :sender)
  end
end

The attached initializers re...

There are three ways to define your own RSpec matchers, with increasing complexibility and options:

1) Use RSpec::Matchers.define

RSpec::Matchers.define :be_a_multiple_of do |expected|
  match do |actual|
    actual % expected == 0
  end
  
  # optional
  failure_message do |actual|
    "expected that #{actual} would be a multiple of #{expected}"
  end
  
  # optional
  failure_message_when_negated do |actual|
    "expected that #{actual} would not be a multiple of #{expected}"
  end
end

• This is automatically available i...

When you need to add a event listener to hundreds of elements, this might slow down the browser.

An alternative is to register an event listener at the root of the DOM tree (document). Then wait for events to bubble up and check whether the triggering element (event.target) matches the selector before you run your callback.

This technique is called event delegation.

Performance considerations

Because you only register a single listener, registering is ...

A well-written API can be a great asset to the organization that wrote it and to all that use it. Given the importance of good API design, surprisingly little has been written on the subject. In this talk (recorded at Javapolis), Java library designer Joshua Bloch teaches how to design good APIs, with many examples of what good and bad APIs look like.

When you roll custom URLs with hacks like routing-filter, you can put a spec like this into spec/routing/routing_spec.rb:

Spreewald has steps that let you test that e-mails have been sent, using arbitrary conditions in any combination.

The attached file is for legacy purposes only.

Don't use should validate_format_of(...) because that matcher works in weird ways. Use the allow_value matcher instead:

describe Email, '#sender' do
  # > Rspec 3 should syntax
  it { should allow_value("email@addresse.foo").for(:sender) }
  it { should_not allow_value("foo").for(:sender) }
  
  # Rspec 3 expect syntax
  it { is_expected.to allow_value("email@addresse.foo").for(:sender) }
  it { is_expected.not_to allow_value("foo").for(:sender) }
end

Errors that may occur if you do use should validate_format_of(...):
...

You can write regular expressions some different ways, e.g. /regex/ and %r{regex}. For examples, look here.

Remember that it is always a good idea to match a regex visually first.

Characters

Literal Characters

[ ] \ ^ $ . | ? * + ( )

Character Classes

[ae]            matches a and e, e.g. gr[ae]y => grey or gray => but NOT graay or graey
[0-9]  ...

The following example is from the Cucumber wiki:

Given a blog post named "Random" with Markdown body
  """
  Some Title, Eh?
  ==============
  Here is the first paragraph of my blog post. Lorem ipsum dolor sit amet,
  consectetur adipiscing elit.
  """

That multi-line string will be given as the last block argument in your step definitions:

Given /^a blog post named "([^\"]*)" with Markdown body$/ do |title, markdown|
  Post.create!(:title =...

Our awesome collection of rspec helpers (formerly known as "spec_candy.rb") is now available as a gem. It works, it is tested and there will be updates.

Usage

Add rspec_candy to your Gemfile.

Add require 'rspec_candy/helpers' to your spec_helper.rb, after the rspec requires.

List of features

See on GitHub