Do End Your Braces

Braces and do/end are completely swappable—almost all the time. They have different precedence. It’s not often that anyone comes across what this means in practice.

In shoulda, these do different things:

should redirect_to('#edit') { article_edit_path(@article) }
should redirect_to('#edit') do
  article_edit_path(@article)
end

To get a better grasp on the differences, consider these two simple methods:

def outer(inner, &block)
  inner
  block.call('outer') if block_given?
end

def inner(&block)
  block.call('inner') if block_given?
  1
end

Here outer is analogous to should and inner to redirect_to. Instead of having any real logic, though, they call a block with what they are. In practice:

outer inner {|where| puts "#{where} called me"}

# "inner called me"

outer inner do |where|
  puts "#{where} called me"
end

# "outer called me"

Short, explicit test setups

You probably know about this Factory Girl definition syntax:

FactoryGirl.define do
  factory :user do
    name 'Connie Customer'
  end
end

But did you know about this Factory Girl invocation syntax?

setup do
  @user = create(:user)
end

Or:

setup do
  @user = build(:user)
end

Or:

setup do
  post :create, user: attributes_for(:user)
end

It’s in there.

Configuration for Test::Unit / Shoulda:

class ActiveSupport::TestCase
  include FactoryGirl::Syntax::Methods
end

Configuration for RSpec:

RSpec.configure do |config|
  config.include FactoryGirl::Syntax::Methods
end

Configuration for Cucumber:

World FactoryGirl::Syntax::Methods

Written by Dan Croak.

This week in open source

paperclip

Much of the work over the past week was done in paperclip, so now you can upload files to your Rails apps with more flare and style!

It now supports an option for keeping old files, so you can pass :keep_old_files to has_attached_file and, when you destroy an attachment (@user.avatar.destroy) it won’t actually delete the underlying files (345ec74). Many people find this useful for S3 storage, which hints that there may be a deeper problem elsewhere. This is thanks to Eike Bernhardt (teefax) but was originally written by Philippe Creux (pcreux).

Christoph Lupprich (kitto) saw a quick way to speed up the #public_url method for Fog storage using AWS as the provider, so he did (989ec0e).

I’ve long wanted a migration helper, and Daniel Schierbeck (dasch) wrote it with some git cleanup from Alexey Mahotkin (693b528, b922111, f82c0d9, f3eacd2, e0a6732, ffbfc24, 500f1bb, b70ffbc, 65a6ae8). It looks like this:

class AddAvatarColumnsToUser < ActiveRecord::Migration
  def self.up
    change_table :users do |t|
      t.has_attached_file :avatar
    end
  end

  def self.down
    drop_attached_file :users, :avatar
  end
end

There were also some important internal changes. For example, Prem Sichanugrist (sikachu) replaced the AWS::S3 gem with AWS::SDK (1df1b03, 81129ad, 88a8af9, 75f413d, 2cf7378). He called out AWS (amazonwebservices) and Trevor Rowe (trevorrowe) for helping, and John Joseph Bachir (jjb) updated the docs appropriately (308f1a0).

Prem also got Paperclip passing on Rubinius (001fd99).

In bug fixes, base URLs with a ? but no = will produce Paperclip URLs using ? (128d664 and bb22be3). Prem thinks that’s the right behavior now, but it’s tricky to nail down.

Nick Padgett (npadgett) found an edgecase where we were calling strip on a non-string object, sometimes, and fixed that (34913f1).

Dimitrij Denissenko (dim) handled the case where using the :id_partition pattern in a URL or path pattern raises a NoMethodError on an unsaved resource (ac82244). He and I are now enemies for life for his use of nil.

Prem fixed another bug: if you have a path or URL pattern with :class in it it will show a warning. He removed this warning (b4ff2c5).

Prem worked with Steve Richert (laserlemon) to show the Gemnasium results in the README (3e20907 and 777ac90), and Prem also updated the README to be more readable (adcd03c).

fake_braintree

The fake credit card processor, fake_braintree, hit 0.0.6 (eed875e and 0934f1e) this week as Ben Orenstein (r00k) added support for discounted subscriptions (757c0aa) and Gabe Berke-Williams (gabebw) exposed the transactions that have run (8dde09c and ab93137).

suspenders

Taking a stance on whether we play along with the little Open Directory Project game, suspenders now defaults to NOODP on every page which, as Matt Jankowski (mjankowski) points out, tells Web crawlers to never bother looking for ODP details (6275d0f).

shoulda-matchers

The sweet shoulda-matchers collection of RSpec matchers now has more accurate error messages for the allow_value matcher (25c2623), thanks to Clemens Helm (clemenshelm). It uses the underlying internationalization information to generate this.

bourbon

Another documentation update on bourbon as Phil LaPier (plapier) explained that multiple background images with shorthand notation are unsupported (798aa1c), after clarifying that multiple background images themselves have fancy comma-separated syntax (aa66831).

This week in open source

kumade

It was a refactoring week on kumade, the Heroku deployer. Gabe Berke-Williams and Josh Clayton refactored the Packager class, splitting it out into handlers for Jammit, Less, and no-op packagers (d854184). Then Gabe Berke-Williams (gabebw) went off on his own to introduce a CommandLine class, wrapping Cocaine with some Thor (0c3840d and 72424c0). Meanwhile Joshua Clayton (joshuaclayton) changed should_not have_received to should have_received.never (6652197).

suspenders

Our app making gem, suspenders, saw some updates from Matt Jankowski (mjankowski): Rails 3.1 (10ac09a, 97881fc, 354321d, c8f8c85, and db08366), bourbon (d490b36), flutie (e0bab83), the Hoptoad → Airbrake name change (6def3d7), and tying together the asset pipeline (a4ce3e7 and c760a33).

paul_revere

We have a one-off announcement plugin for Rails, named paul_revere. Nick Quaranto (qrush) released version 0.2.1 (3574b40 and dfbf940).

shoulda-matchers

Our collection of RSpec matchers, shoulda-matchers, is not passing on my laptop. Prem Sichanugrist (sikachu) built out the continuous integration tests more to attempt to clarify the issue (3d94390, 4450c86, 1a3aeec, 6785f59, f1f5e6d).

bourbon

The SCSS gem, bourbon, saw actual words being used by Matt Jankowski (mjankowski) in the documentation (b8afdea), plus Phil LaPier (plapier) updated the docs with resources for investigating browser compatibility (35539c9). He also added this sweet variable, $all-text-inputs, representing all HTML5 textual inputs like color, date, phone, password, URL, and so on (d1def76 and fb299e6). To wrap it all up he released version 0.1.8 (f3046bd).

paperclip

Lots of bug fixes in paperclip, the Rails image uploader plugin gem, this week. Cody Caughlan (ruckus) added S3 support for an HTTP proxy (4661cef). Denis Yagofarov (denyago) preserved the path set for the Cocaine gem (3a35ba9). Aditya Sanghi (asanghi) gave us a warning when two models save files to the same place on the filesystem (8d43e19). Daniel Evans (danielevans) removes the temporary file after it has been uploaded and processed (748332e). Edison (edison) added a feature where you can set the file system path based on a method in the model (996ca87 and 1738f3c).

Prem Sichanugrist (sikachu) then attacked some outstanding bugs: escape the URL (23cb822), handle a space leak where an array was growing by one for each request (d18d814), make the Interpolations.hash class method confirm to the expected signature for hash methods (e526c86), and preserve the filename for S3 attachments when we know the filename (522a53e).

Prem then did some refactoring, splitting the storage tests into individual unit tests (0ca98d1, d204c7d, 31d74d6), stubbing Cocaine (0a77f64), removing some noisy debugging (fd891e0), and cleaning up whitespace (825e1f1 and b2cac53). After all of this he released version 2.4.2 (9edeb01).

factory_girl

Features and refactorings were the name of the game for factory_girl, the fixture replacement for Rails. Joe Ferris and Josh Clayton fixed traits so now you can override attributes of them. They did this by refactoring attributes, introducing an intermediate Declaration object that knows how to compile down to a full factory (a154e64 and f8638b). Joe Ferris (jferris) made callbacks into first-class objects with validations (0f87ca3, ede051f, and 4d30663). Thomas Walpole (twalpole) fixed an inconsistency, ensuring that parent callbacks are called before child callbacks (27c4b21).

Oh man check this: Joel Meador (janxious) updated the ChangeLog (306e51b and 88cf88)! Joshua Clayton (joshuaclayton) went along with this, too (9c95a2) before releasing version 2.1.2 (58e75bc and c1360e).

capybara-webkit

The capybara-webkit test driver, which Joe presented about at Boston Ruby, continues to improve. Gabe Berke-Williams (gabebw) gave us a documentation edit (f493b22), while Matthew Mongeau (halogenandtoast) striped and normalized spaces for consistency with Selenium (6d92f35) and also added support for unknown content types (ff0a6e7, 9257fe3, and 353fe86)

The Quest Continues: Introducing capybara-webkit

We recently blogged about our experiences and ongoing efforts to discover and improve tools for Javascript testing. In closing, we mentioned that we were fairly happy with Akephalos, but we didn’t believe the quest was over. Today, the quest continues.

Akephalos

Akephalos is a well-written driver that integrates soundly with the htmlunit virtual browser. However, as well-integrated as Akephalos is into both Capybara and htmlunit, it can only ever be as strong as htmlunit. As our applications became more sophisticated and large, we began to run into issues with htmlunit.

• Bugs: as previously mentioned, there are bugs in htmlunit, specifically with jQuery’s live. Although all browser implementations have bugs, it’s more useful if tests experience the same bugs as actual browsers.
• Compatibility: htmlunit doesn’t fully implement the feature set that modern browsers do. For example, it doesn’t fully handle DOM ranges or Ajax file uploads.
• Rendering: htmlunit doesn’t actually render the page, so tests that depend on CSS visibility or positioning won’t work.
• Performance: when most of your tests use Javascript, test suites with htmlunit start to crawl. It takes a while to start up a test with Akephalos, and a large test suite can easily take 10 or 15 minutes.

These issues made us realize that virtual browsers like envjs and htmlunit are never going to keep pace with actual browsers. If we want to write applications using features from the latest and greatest browsers, we’re going to need to test with them, too.

Selenium

That brought us back to the old mirage: Selenium. Selenium is well-supported, well-maintained, and works with real browsers. Integration with Ruby tests has improved considerably since the old Webrat days, and speed is better in some cases, as real browsers have been heavily optimized.

However, Selenium still has some ongoing issues that aren’t easy to solve:

• Timing: because Selenium uses a real browser, it doesn’t have as much control as a virtual browser does. This leads to issues with timing, causing erratic test failures.
• Overhead: real browsers come with features we don’t need, like a UI and plugins. This slows things down a bit.
• Gotchas: real browsers come with strange edge cases. Using Selenium and Firefox, sometimes the tests crash because Firefox tries to update the browser. Firefox doesn’t allow more than one instance to run at once. These gotchas are inevitable, because real browsers weren’t designed to be driven programatically.

We were forced to use Selenium because we needed all the capabilities of a real browser, but all these issues kept us looking for something better.

capybara-webkit

What we need was a real rendering engine coupled with a full Javascript and DOM implementation, but without all the cruft of a GUI browser. What we really wanted was a headless implementation of WebKit’s rendering engine that could be driven by Capybara tests. After Tristan “Websockets” Dunn showed me PhantomJs, I realized this might be possible using Qt’s WebKit implementation.

It was possible. I’d like to introduce a headless WebKit driver for capybara: capybara-webkit.

capybara-webkit has the following benefits:

• Compatibility: uses a real rendering engine (WebKit)
• Simplicity: runs headlessly, and designed to be controlled programatically
• Performance: faster than htmlunit - the test suites we’ve tried it on so far yielded 15-25% speed increases

The holy grail?

We designed capybara-webkit to solve the problems we had with other solutions, and so far it fits the bill nicely. We believe the quest is far from over, but we invite you to try out capybara-webkit on your own and see if this latest tool can take you a little further on your quest for the perfect testing solution.

Please keep in mind that this is a new driver and isn’t battle-tested as well as Akephalos or Selenium. If you discover any bugs, please report them in Github Issues. We’d also be happy to accept tested patches.

Next Steps & Related Reading

End-to-end testing with RSpec integration tests and Capybara

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