Myron Marston is taking over leadership of the RSpec project, and will be the lead maintainer of the rspec-core, rspec-expectations, and rspec-mocks gems.

Andy Lindeman is taking over as lead maintainer of the rspec-rails gem.

Myron Marston is RSpec’s new project lead

Myron Marston has been contributing to RSpec since the ramp up to the 2.0 release in 2010, and joined the core team in early 2011. In addition to solid contributions to the code base, Myron has taken responsibility for many bug reports, feature requests, pull requests, etc. He also makes a habit of answering RSpec-related questions on Stack Overflow and Twitter, and he does this all with thoughtfulness, patience, and wisdom.

I can’t think of a better choice to lead the RSpec project, so I invited him to do so. Thankfully, SEOmoz, Myron’s employer, is allowing him to work on RSpec during work hours, and so he accepted.

In addition to the overall project lead, Myron will be the lead maintainer of the rspec-core, rspec-expectations, and rspec-mocks gems. While Myron uses these core rspec libs every day for his work, he doesn’t do much with Rails, so we discussed and agreed that we’d ask somebody else to take care of the rspec-rails gem. Enter Andy Lindeman.

Andy Lindeman is the new lead maintainer of rspec-rails

Andy Lindeman is the newest addition to the rspec core team. Like Myron, Andy takes great care in shepherding pull requests and answering questions in addition to making his own rock solid contributions. Andy also writes Rails apps and does Rails training at Big Nerd Ranch, which puts him in a great position to ensure that rspec-rails keeps up with changes in Rails remains a great choice for developing Rails apps.

Thanks in part to Big Nerd Ranch for their support of Andy’s work on RSpec, Andy has agreed to take the lead on rspec-rails.

As for me …

When Dave Astels introduced Steven Baker’s new RSpec library to me back in 2005, I started submitting patches, Steven gave me commit rights and, a year later, he decided to move on to other work and offered me leadership of the project. I was overjoyed to accept.

In those days, I was teaching TDD/Refactoring courses for Object Mentor. I was encouraged to work on OSS in my bench time, and I was particularly interested in tools that helped to promote the documentation and design aspects of TDD. RSpec and some of the early definitions/discussions of BDD (“it’s all behavior!”) fit perfectly into my thinking and my world.

After I left Object Mentor, RSpec was part of my day to day work on Ruby applications, but most of my work on its maintenance moved to my spare time. This was fine at first, as I had the support of employers and family, but I found myself doing less and less of pretty much everything else that I enjoy and learn from.

Back in June, I joined a project team at DRW Trading that deals in a lot of Clojure and almost no Ruby. In the roughly 6 months since, I’ve been learning a new domain, a new language, new programming models, and even a new text editor. I consider myself extraordinarily fortunate to be able to learn all of these new things, but I’ve found myself less and less able to balance my work on RSpec with my job and with everything else I want to do.

And so, it is time.

Of course, I’ll continue to contribute to the project and surrounding conversation, and I look forward to seeing all my friends in the community at assorted conferences in the coming year(s). I’ll just be arriving without my RSpec Lead hat on.

Thank you to Steven Baker for handing me the wheel, and thank you to everybody who has participated in the project and all RSpec users for your support over these 6+ years. It’s been a great honor and a great pleasure.

Thanks to all who contributed. Special thanks to Myron Marston and Andy Lindeman for their personal contributions to the code as well as a great job shepherding pull requests from several new contributors.

UPDATE: If you’re an rspec/rails/capybara user, be sure to read Andy Lindeman’s blog post on Capybara-2.0 and rspec-rails.

Docs

RDoc

• http://rubydoc.info/gems/rspec-core
• http://rubydoc.info/gems/rspec-expectations
• http://rubydoc.info/gems/rspec-mocks
• http://rubydoc.info/gems/rspec-rails

Cucumber features

• http://relishapp.com/rspec/rspec-core
• http://relishapp.com/rspec/rspec-expectations
• http://relishapp.com/rspec/rspec-mocks
• http://relishapp.com/rspec/rspec-rails

Release notes

rspec-core-2.12.0

full changelog

Enhancements

• Add support for custom ordering strategies for groups and examples. (Myron Marston)
• JSON Formatter (Alex Chaffee)
• Refactor rake task internals (Sam Phippen)
• Refactor HtmlFormatter (Pete Hodgson)
• Autotest supports a path to Ruby that contains spaces (dsisnero)
• Provide a helpful warning when a shared example group is redefined. (Mark Burns).
• --default_path can be specified as --default-path. --line_number can be specified as --line-number. Hyphens are more idiomatic command line argument separators (Sam Phippen).
• A more useful error message is shown when an invalid command line option is used (Jordi Polo).
• Add format_docstrings { |str| } config option. It can be used to apply formatting rules to example group and example docstrings. (Alex Tan)
• Add support for an .rspec-local options file. This is intended to allow individual developers to set options in a git-ignored file that override the common project options in .rspec. (Sam Phippen)
• Support for mocha 0.13.0. (Andy Lindeman)

Bug fixes

• Remove override of ExampleGroup#ancestors. This is a core ruby method that RSpec shouldn’t override. Instead, define ExampleGroup#parent_groups. (Myron Marston)
• Limit monkey patching of shared example/context declaration methods (shared_examples_for, etc.) to just the objects that need it rather than every object in the system (Myron Marston).
• Fix Metadata#fetch to support computed values (Sam Goldman).
• Named subject can now be referred to from within subject block in a nested group (tomykaira).
• Fix fail_fast so that it properly exits when an error occurs in a before(:all) hook (Bradley Schaefer).
• Make the order spec files are loaded consistent, regardless of the order of the files returned by the OS or the order passed at the command line (Jo Liss and Sam Phippen).
• Ensure instance variables from before(:all) are always exposed from after(:all), even if an error occurs in before(:all) (Sam Phippen).
• rspec --init no longer generates an incorrect warning about --configure being deprecated (Sam Phippen).
• Fix pluralization of 1 seconds (Odin Dutton)
• Fix ANSICON url (Jarmo Pertman)
• Use dup of Time so reporting isn’t clobbered by examples that modify Time without properly restoring it. (David Chelimsky)

Deprecations

• share_as is no longer needed. shared_context and/or RSpec::SharedContext provide better mechanisms (Sam Phippen).
• Deprecate RSpec.configuration with a block (use RSpec.configure).

rspec-expectations-2.12.0

full changelog

Enhancements

• Colorize diffs if the --color option is configured. (Alex Coplan)
• Include backtraces in unexpected errors handled by raise_error matcher (Myron Marston)
• Print a warning when users accidentally pass a non-string argument as an expectation message (Sam Phippen)
• =~ and match_array matchers output a more useful error message when the actual value is not an array (or an object that responds to #to_ary) (Sam Phippen)

Bug fixes

• Fix include matcher so that expect({}).to include(:a => nil) fails as it should (Sam Phippen).
• Fix be_an_instance_of matcher so that Class#to_s is used in the description rather than Class#inspect, since some classes (like ActiveRecord::Base) define a long, verbose #inspect. (Tom Stuart)

rspec-mocks-2.12.0

full changelog

Enhancements

• and_raise can accept an exception class and message, more closely matching Kernel#raise (e.g., foo.stub(:bar).and_raise(RuntimeError, "message")) (Bas Vodde)
• Add and_call_original, which will delegate the message to the original method (Myron Marston).

Deprecations:

• Add deprecation warning when using and_return with should_not_receive (Neha Kumari)

rspec-rails-2.12.0

full changelog

Enhancements

• Support validation contexts when using #errors_on (Woody Peterson)
• Include RequestExampleGroup in groups in spec/api

Bug fixes

• Add should and should_not to CollectionProxy (Rails 3.1+) and AssociationProxy (Rails 3.0). (Myron Marston)
• controller.controller_path is set correctly for view specs in Rails 3.1+. (Andy Lindeman)
• Generated specs support module namespacing (e.g., in a Rails engine). (Andy Lindeman)
• render properly infers the view to be rendered in Rails 3.0 and 3.1 (John Firebaugh)
• AutoTest mappings involving config/ work correctly (Brent J. Nordquist)
• Failures message for be_new_record are more useful (Andy Lindeman)

One of the original ideas behind BDD was that testing should be about behavior at all levels. Effectively, all automated tests can be viewed as “functional tests” of entry points, be they user facing or internal, crossing procedural boundaries or not. In this talk we’ll explore approaches to focusing on the behavior of objects, using language that also serves to document the expected behavior in ways useful to both technical and non-technical stakeholders.

The Agile Testing & BDD eXchange is a one-day conference with talks, open-space discussions and focus on ‘quality time’ between presenters and attendees. There is a nice blend of technical talks like Uncle Bob Martin talking about how to apply SOLID principles to test design, and more process oriented talks like Ellen Gottesdiener’s talk on product definition through structured conversation.

You can read the full program and purchase tickets at http://bit.ly/S0Ypb8 (be sure to use the promo-code “bddxnyc-community-discount”).

What: Agile Testing & BDD eXchange NYC

When: October 1st 2012

Where: The Ace Hotel NYC

Twitter: #BDDXNYC

Thanks also to Myron for all his work on two great new features: the new expectation syntax and support for stubbing constants.

rspec-core-2.11.0

full changelog

Enhancements

• Support multiple --example options. (Daniel Doubrovkine @dblock)
• Named subject e.g. subject(:article) { Article.new }
  • see http://blog.davidchelimsky.net/2012/05/13/spec-smell-explicit-use-of-subject/ for background.
  • thanks to Bradley Schaefer for suggesting it and Avdi Grimm for almost suggesting it.
• config.mock_with and config.expect_with yield custom config object to a block if given
  • aids decoupling from rspec-core’s configuation
• include_context and include_examples support a block, which gets eval’d in the current context (vs the nested context generated by it_behaves_like).
• Add config.order = 'random' to the spec_helper.rb generated by rspec --init.
• Delay the loading of DRb (Myron Marston).
• Limit monkey patching of describe onto just the objects that need it rather than every object in the system (Myron Marston).

Bug fixes

• Support alternative path separators. For example, on Windows, you can now do this: rspec spec\subdir. (Jarmo Pertman @jarmo)
• When an example raises an error and an after or around hook does as well, print out the hook error. Previously, the error was silenced and the user got no feedback about what happened. (Myron Marston)
• --require and -I are merged among different configuration sources (Andy Lindeman)
• Delegate to mocha methods instead of aliasing them in mocha adapter.

rspec-expectations-2.11.0

full changelog

Enhancements

• Expand expect syntax so that it supports expections on bare values in addition to blocks (Myron Marston).
• Add configuration options to control available expectation syntaxes (Myron Marston):
  • RSpec.configuration.expect_with(:rspec) { |c| c.syntax = :expect }
  • RSpec.configuration.expect_with(:rspec) { |c| c.syntax = :should }
  • RSpec.configuration.expect_with(:rspec) { |c| c.syntax = [:should, :expect] }
  • RSpec.configuration.add_should_and_should_not_to Delegator

Bug fixes

• Allow only Numeric values to be the “actual” in the be_within matcher. This prevents confusing error messages. (Su Zhang @zhangsu)
• Define should and should_not on BasicObject rather than Kernel on 1.9. This makes should and should_not work properly with BasicObject-subclassed proxy objects like Delegator. (Myron Marston)

rspec-mocks-2.11.0

full changelog

Enhancements

• expose ArgumentListMatcher as a formal API
  • supports use by 3rd party mock frameworks like Surrogate
• Add stub_const API to stub constants for the duration of an example (Myron Marston).

Bug fixes

• Fix regression of edge case behavior. double.should_receive(:foo) { a } was causing a NoMethodError when double.stub(:foo).and_return(a, b) had been setup before (Myron Marston).
• Infinite loop generated by using any_instance and dup. (Sidu Ponnappa @kaiwren)
• double.should_receive(:foo).at_least(:once).and_return(a) always returns a even if :foo is already stubbed.
• Prevent infinite loop when interpolating a null double into a string as an integer ("%i" % double.as_null_object). (Myron Marston)
• Fix should_receive so that null object behavior (e.g. returning self) is preserved if no implementation is given (Myron Marston).
• Fix and_raise so that it raises RuntimeError rather than Exception by default, just like ruby does. (Andrew Marshall)

rspec-rails-2.11.0

full changelog

Enhancements

• The generated spec/spec_helper.rb sets config.order = "random" so that specs run in random order by default.
• rename render_template to have_rendered (and alias to render_template for backward compatibility)

Bug fixes

• “uninitialized constant” errors are avoided when using using gems like rspec-rails-uncommitted that define Rspec::Rails before rspec-rails loads (Andy Lindeman)

Explicit use of the “subject” abstraction is a code smell, and should be refactored to use a more intention revealing name whenever possible.

One liners

rspec-core supports a one-liner syntax to reduce the noise of common requirements like validations:

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describe Article do
  it { should validate_presence_of(:title) }
end

Without support for this syntax, the same example might look like this:

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describe Article do
  it "validates presence of :title" do
    article = Article.new
    article.should validate_presence_of(:title)
  end
end

The benefit of this more verbose example is that it we can read it and understand all the parts right away: an object is initialized and assigned to a local variable, then that variable is used for an expectation.

The benefit of the one-liner is that it’s terse and expressive, but that comes at a cost: you can’t see what the expectation is being evaluated against, so you have to understand some underlying mechanics in order to isolate/understand a failure.

The subject abstraction

Behind the scenes, the one-liner uses a “subject” abstraction supported by two methods named subject. One is a class method on ExampleGroup, used to declare the “subject” of all of the examples in the group:

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describe Article do
  subject { Article.new }
  # ...
end

The other is an instance method on ExampleGroup. The first time it is called within an example the block passed to the class’ subject method is evaluated and its result memoized, returning the same value from that and each subsequent subject call:

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describe Article do
  # ...
  it "validates presence of :title" do
    subject.should validate_presence_of(:title)
  end
end

Here is what they look like together:

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# not recommended
describe Article do
  subject { Article.new }

  it "validates presence of :title" do
    subject.should validate_presence_of(:title)
  end
end

The problem with this example is that the word “subject” is not very intention revealing. That might not appear problematic in this small example because you can see the declaration on line 3 and the reference on line 6. But when this group grows to where you have to scroll up from the reference to find the declaration, the generic nature of the word “subject” becomes a hinderance to understanding and slows you down.

In this case, we’d be better served by using a method (or a let declaration) with an intention revealing name:

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describe Article do
  def article; Article.new; end

  it "validates presence of :title" do
    article.should validate_presence_of(:title)
  end
end

If we can do that, you might wonder why we have “subject” at all. Well, it was originally designed to never be seen:

Implicit subject

Note in the example with subject { Article.new }, that the subject declaration is initializing an Article with no args. Since RSpec knows that the first argument to describe is the Article class, it can store a similar block in the background as a default, implicit subject declaration, leaving us with:

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# refactoring toward implicit step 1
describe Article do
  it "validates presence of :title" do
    subject.should validate_presence_of(:title)
  end
end

That’s a little better, but now subject appears out of nowhere in the example, leaving the reader to wonder where it came from. To remove the need for explicitly referencing subject, the example delegates should and should_not to subject when it is, itself, the receiver:

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# refactoring toward implicit step 2
describe Article do
  it "validates presence of :title" do
    should validate_presence_of(:title)
  end
end

Starting that line with “should” seems a bit odd though, so the final step is to do it all in one line:

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describe Article do
  it { should validate_presence_of(:title) }
end

Now we have a completely implicit subject, and the result reads quite nicely in both the code and the output when run with --format documentation:

Article
  should validate presence of :title

We still need to trust that something is doing some work for us but it’s all operating at the same level of abstraction, so we don’t have to try to interpret half of the functionality.

Avoid explicit use of subject

Intention revealing names are crucial if you want to be able to quickly scan and understand code as you navigate around different parts of a system. This is as true for specs as it is for implementation, and the generic nature of the word “subject” makes it a poor choice when a more intention revealing name can be used.

Is an explicit subject ever OK?

Guidelines are guidelines; YMMV. In general I would recommend that if there is a reasonable way to use an intention revealing name instead of “subject”, you should. The only use case I can think of in RSpec in which another name can’t be used is the one liner syntax:

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describe AmericanCitizen do
  context "18 years of age" do
    subject { Person.new(:birthdate => 18.years.ago) }
    it { should     be_able_to(:vote)   }
    it { should     be_able_to(:enlist) }
    it { should_not be_able_to(:drink)  } # srsly?
  end
end

Here we have to use subject because that’s the only way to tell RSpec where to send should and should_not. In my opinion, any other explicit appearance of subject can and should be refactored to use an intention revealing name.

Update 2012-05-15

Based on feedback on this post, I added support for a “named subject,” which lets you reference the declared subject implicitly in one-liners and with an intention revealing name in standard examples:

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describe CheckingAccount, "with a non-zero starting balance" do
  subject(:account) { CheckingAccount.new(Money.new(50, :USD)) }
  it { should_not be_overdrawn }
  it "has a balance equal to the starting balance" do
    account.balance.should eq(Money.new(50, :USD))
  end
end

This will be released with rspec-core-2.11. Keep your eyes out for it!

rspec-mocks-2.10.1

full changelog

Bug fixes

• fix regression of edge case behavior
  • fixed failure of object.should_receive(:message).at_least(0).times.and_return value
  • fixed failure of object.should_not_receive(:message).and_return value

rspec-rails-2.10.1

full changelog

Bug fixes

• fix regression introduced in 2.10.0 that broke integration with Devise

http://rubydoc.info/gems/rspec-core

http://rubydoc.info/gems/rspec-expectations

http://rubydoc.info/gems/rspec-mocks

http://rubydoc.info/gems/rspec-rails

Cucumber docs

http://relishapp.com/rspec/rspec-core

http://relishapp.com/rspec/rspec-expectations

http://relishapp.com/rspec/rspec-mocks

http://relishapp.com/rspec/rspec-rails

rspec-core-2.10.0

full changelog

Enhancements

• Add prepend_before and append_after hooks (preethiramdev)
  • intended for extension libs
  • restores rspec-1 behavior
• Reporting of profiled examples (moro)
  • Report the total amount of time taken for the top slowest examples.
  • Report what percentage the slowest examples took from the total runtime.

Bug fixes

• Properly parse SPEC_OPTS options.
• example.description returns the location of the example if there is no explicit description or matcher-generated description.
• RDoc fixes (Grzegorz Świrski)
• Do not modify example ancestry when dumping errors (Michael Grosser)

rspec-expectations-2.10.0

full changelog

Enhancements

• Add new start_with and end_with matchers (Jeremy Wadsack)
• Add new matchers for specifying yields (Myron Marson):
  • expect {...}.to yield_control
  • expect {...}.to yield_with_args(1, 2, 3)
  • expect {...}.to yield_with_no_args
  • expect {...}.to yield_successive_args(1, 2, 3)
• match_unless_raises takes multiple exception args

Bug fixes

• Fix be_within matcher to be inclusive of delta.
• Fix message-specific specs to pass on Rubinius (John Firebaugh)

rspec-mocks-2.10.0

full changelog

Bug fixes

• fail fast when an exactly or at_most expectation is exceeded

rspec-rails-2.10.0

full changelog

Bug fixes

• render_views called in a spec can now override the config setting. (martinsvalin)
• Fix render_views for anonymous controllers on 1.8.7. (hudge, mudge)
• Eliminate use of deprecated process_view_paths
• Fix false negatives when using route_to matcher with should_not
• controller is no longer nil in config.before hooks
• Change request.path_parameters keys to symbols to match real Rails environment (Nathan Broadbent)
• Silence deprecation warnings in pre-2.9 generated view specs (Jonathan del Strother)

full changelog

Bug fixes

• Provide a helpful message if the diff between two objects is empty.
• Fix bug diffing single strings with multiline strings.
• Fix for error with using custom matchers inside other custom matchers (mirasrael)
• Fix using execution context methods in nested DSL matchers (mirasrael)

rspec-core-2.9.0 / 2012-03-17

full changelog

Enhancements

• Support for “X minutes X seconds” spec run duration in formatter. (uzzz)
• Strip whitespace from group and example names in doc formatter.
• Removed spork-0.9 shim. If you’re using spork-0.8.x, you’ll need to upgrade to 0.9.0.

Bug fixes

• Restore --full_backtrace option
• Ensure that values passed to config.filter_run are respected when running over DRb (using spork).
• Ensure shared example groups are reset after a run (as example groups are).
• Remove rescue false from calls to filters represented as Procs
• Ensure described_class gets the closest constant (pyromaniac)
• In “autorun”, don’t run the specs in the at_exit hook if there was an exception (most likely due to a SyntaxError). (sunaku)
• Don’t extend groups with modules already used to extend ancestor groups.
• its correctly memoizes nil or false values (Yamada Masaki)

rspec-expectations-2.9.0 / 2012-03-17

full changelog

Enhancements

• Move built-in matcher classes to RSpec::Matchers::BuiltIn to reduce pollution of RSpec::Matchers (which is included in every example).
• Autoload files with matcher classes to improve load time.

Bug fixes

• Align respond_to? and method_missing in DSL-defined matchers.
• Clear out user-defined instance variables between invocations of DSL-defined matchers.
• Dup the instance of a DSL generated matcher so its state is not changed by subsequent invocations.
• Treat expected args consistently across positive and negative expectations (thanks to Ralf Kistner for the heads up)

rspec-mocks-2.9.0 / 2012-03-17

full changelog

Enhancements

• Support order constraints across objects (preethiramdev)

Bug fixes

• Allow a as_null_object to be passed to with
• Pass proc to block passed to stub (Aubrey Rhodes)
• Initialize child message expectation args to match any args (#109 – preethiramdev)

rspec-rails-2.9.0 / 2012-03-17

full changelog

Enhancments

• add description method to RouteToMatcher (John Wulff)
• Run “db:test:clone_structure” instead of “db:test:prepare” if Active Record’s schema format is “:sql”. (Andrey Voronkov)

Bug fixes

• mock_model(XXX).as_null_object.unknown_method returns self again
• Generated view specs use different IDs for each attribute.

• TDD is about specifying behavior, not structure.
• Validations are behavior, and should be specified.
• Associations are structure, and need not be.

Disclaimer

This is my personal viewpoint, though it is not mine alone. YMMV.

Declarations

ActiveRecord provides a declarative interface for describing the structure and behavior of a model:

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class Article < ActiveRecord::Base
  validates_presence_of :title
  has_many :comments
end

While syntactically similar, these two declarations do fundamentally different things.

Validations are behavior

The validates_presence_of :title declaration changes the behavior of the save method (and other methods that use save), and should be specified explicitly. Here’s an example using shoulda matchers:

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describe Article do
  it { should validate_presence_of(:title) }
end

Even though the matcher’s name looks just like the likely implementation, the validate_presence_of matcher specifies that you can not save an Article without a non-nil value for title, not that the validates_presence_of(:title) declaration exists.

Associations are structure

The has_many declaration exposes a comments method to clients that appears to be a collection of Comment objects. Doing Test-Driven Development, you would add this declaration when a specified behavior requires it e.g.

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describe Article do
  describe "#with_comments_by" do
    it "finds articles with comments by the submitted comment_author" do
      article = Factory(:article)
      article.comments << Factory.build(:comment, :author => "jdoe")
      Article.with_comments_by("jdoe").should eq([article])
    end
  end
end

This example needs a comments method that returns a collection in order to pass. If it doesn’t exist already (because no other example drove you to add it), this would be all the motivation you need to introduce it. You don’t need an example that says it "should have_many(:comments)".

Testing the framework

Some will argue that we don’t need to spec validations either, suggesting that it "should validate_presence_of(:title)" is testing the Rails framework, which we trust is already tested. If you think of TDD as a combination of specification, documentation, and regression testing, then this argument falls short on the specification/documentation front because the validation is behavior and, thus, the spec should specify the validation.

Even if you view testing as nothing more than a safety net against regressions, the argument still falls down in the face of refactoring. If we add a Review class that also has_many(:comments) and validates_presence_of(:title), and we want to extract that behavior to a Postable module that gets included in both Article and Review, we’d want a regression test to fail if we failed to include either of those declarations in the Postable module.

But declarations are already declarative!

Another argument is that declarations supply sufficient documentation. e.g. we can look at rental_contract.rb and know that it validates the presence of :rentable:

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class RentalContract < ActiveRecord::Base
  has_many :monthly_charges
  has_one :rentable, :polymorphic => true

  validates_presence_of :rentable

  def default_monthly_charge
    price / months_applied
  end
end

This is an interesting argument that I think has some merit, but I think it would require an extraordinarily disciplined and consistent approach of using declarations 100% of the time in model files such that each one is the spec for that model, e.g.

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class Contract < ActiveRecord::Base
  validates_presence_of :name
  has_many :monthly_expenses
  calculates_default_monthly_charge
end

100% may sound extreme, but as soon as we define a single method body in any one of the models, the declarative nature of the file begins to degrade, and so does its fitness for the purpose of specification. Plus, if we can only understand the expected behavior of a model by looking at both its spec and its implementation, we’ve lost some of the power of a test-driven approach.

What do you think?

Do you spec associations? If so, what value do you get from doing so? If not, have you run into situations where you wished you had?

Same questions for validations.

The rails-3.2.0.rc2 release broke stub_model in rspec-rails-2.0.0 > 2.8.0. The rspec-rails-2.8.1 release fixes this issue, but it means that when you upgrade to rails-3.2.0.rc2 or greater, you’ll have to upgrade to rspec-rails-2.8.1 or greater.

Because rspec-rails-2.8.1 supports all versions of rails since 3.0, I recommend that you upgrade to rspec-rails-2.8.1 first, and then upgrade to rails-3.2.0.rc2 (or 3.2.0 once it’s out).

Changelog

http://rubydoc.info/gems/rspec-rails/file/Changelog.md

Docs

http://rubydoc.info/gems/rspec-rails

http://relishapp.com/rspec/rspec-rails

• http://rubydoc.info/gems/rspec-core/file/Changelog.md
• http://rubydoc.info/gems/rspec-expectations/file/Changelog.md
• http://rubydoc.info/gems/rspec-mocks/file/Changelog.md
• http://rubydoc.info/gems/rspec-rails/file/Changelog.md

Documentation

While not 100% complete yet, we’ve made great strides on RSpec’s RDoc:

• http://rubydoc.info/gems/rspec-core
• http://rubydoc.info/gems/rspec-expectations
• http://rubydoc.info/gems/rspec-mocks
• http://rubydoc.info/gems/rspec-rails

http://rspec.info is now just a one pager (desperate for some design love – volunteers please email rspec-users@rubyforge.org). All the old pages are redirects to the relevant RDoc at http://rubydoc.info. RSpec-1 info is still available at http://old.rspec.info.

We’ve still got Cucumber features up at http://relishapp.com/rspec, but we’re going to be phasing that out as the primary source of documentation. There are a lot of reasons for this, and I’ll try to follow up with a separate blog post on this topic.

rspec-core

Improved support for tags and filtering

You can now set default tags/filters in either RSpec.configure or a .rspec file and override these tags on the command line. For example, this configuration tells rspec to run all the examples that are not tagged :slow:

# in spec/spec_helper.rb
RSpec.configure do |c|
  c.treat_symbols_as_metadata_keys_with_true_values = true
  c.filter_run_excluding :slow
end

Now when you want run those, you can just do this:

rspec --tag slow

This will override the configuration and run onlly the examples tagged :slow.

—order rand

We added an --order option with two supported values: rand and default.

rspec --order random (or rand) tells RSpec to run the groups in a random order, and then run the examples within each group in random order. We implemented it this way (rather than complete randomization of every example) because we don’t want to re-run expensive before(:all) hooks. A fair tradeoff, as the resulting randomization is just as effective at exposing order-dependency bugs.

When you use --order random, RSpec prints out the random number it used to seed the randomizer. When you think you’ve found an order-dependency bug, you can pass the seed along and the order will remain consistent:

--order rand:3455

--order default tells RSpec to load groups and examples as they are declared in each file.

rspec —init

We added an --init switch to the rspec command to generate a “spec” directory, and “.rspec” and “spec/spec_helper.rb” files with some starter code in them.

rspec-expectations

We discovered that the matcher DSL generates matchers that run considerably slower than classes which implement the matcher protocol. We made some minor improvements in the DSL, but to really improve things we re-implemented every single built-in matcher as a class.

• rspec-core
• rspec-expectations
• rspec-mocks
• rspec-rails

What’s new

Nothing really changed in rspec-rails or rspec-mocks, but rspec-core and rspec-expectations have both gotten some nice improvements.

Configuration (rspec-core)

rspec-core offers a number of configuration options which can be declared on the command line, in a config file (.rspec, ~/.rspec, or custom location), as well as in an RSpec.configure block (in spec/spec_helper.rb by convention). Before this release, some options, but not all, could be stored in config files and then overridden on the command line. The problems were that it was inconsistent (not all options worked this way), and we couldn’t override options that were set in RSpec.configure blocks.

With this release, almost all options declared in RSpec.configure can be overridden from the command line, and --tag options can override their inverses. For example, if you have this in .rspec:

--tag ~slow:true

That means “exclude examples tagged :slow => true”. So the following example would be excluded:

it "does something", :slow => true do
  # ...
end

You can also exclude that example from RSpec.configure like this:

RSpec.configure do |c|
  c.filter_run_excluding :slow => true
end

Note: the naming is different for historical reasons, and we will reconcile that in a future release, but for now, just know that --tag on the command line and in .rspec is synonymous with filter_run_[including|excluding] in RSpec.configure.

Override from command line

Whether the default is stored in .rspec or RSpec.configure, it can be overridden from the command line like this:

rspec --tag slow:true

“Profiles” in custom options files

The rspec command has an --options option that let’s store command line args in arbitrary files and tell RSpec where to find them. For example, you could set things up so your normal spec run excludes the groups and examples marked :slow by putting this in .rspec:

--tag ~slow

Now add a .slow file with:

--tag slow

Now run rspec to run everything but the slow specs, and run rspec --options .slow or rspec -O.slow to run the slow ones.

Override from Rake task

RSpec’s Rake task supports an rspec_opts config option, which means you can set up different groupings from rake tasks as well. The fast/slow example above would look like this:

namespace :spec do
  desc "runs the fast specs"
  RSpec::Core::RakeTask.new(:fast) do |t|
    t.rspec_opts = '--options .fast'
  end
  RSpec::Core::RakeTask.new(:slow) do |t|
    t.rspec_opts = '--options .slow'
  end
end

Or ..

namespace :spec do
  desc "runs the fast specs"
  RSpec::Core::RakeTask.new(:fast) do |t|
    t.rspec_opts = '--tag ~slow'
  end
  RSpec::Core::RakeTask.new(:slow) do |t|
    t.rspec_opts = '--tag slow'
  end
end

Implicit true value for tags/filters

This is not new in rspec-2.8, but all the tags/filters in the example above can be written without explicitly typing true:

--tag slow
--tag ~slow







RSpec.configure {|c| c.filter_run_excluding :slow}

it "does something", :slow do

You have to set a config option to enable this in rspec-2.x:

RSpec.configure {|c| c.treat_symbols_as_metadata_keys_with_true_values = true}

In rspec-3.0, this will be the default, but without setting this value in 2.x you’ll get a deprecation warning when you try to configure things this way. It’s ugly, I know, but this enabled us to introduce the new behavior without breaking compatibility with some suites in a minor release.

Ordering

With 2.8, you can now run the examples in random order, using the new --order option:

--order rand

The order is randomized with some reasonable caveats:

• top level example groups are randomized
• nested groups are randomized within their parent group
• examples are randomized within their group

This provides a very useful level of randomization while maintaining the integrity of before/after hooks, subject, let, etc.

If you want to run the examples in the default ordering (file-system load order for files and declaration order for groups/examples), you can override the order from the command line:

--order default

Pseudo-randomization

The randomization is managed by Ruby’s pseudo-randomization. This means that if you find an order dependency and want to debug/fix it, you can fix the order by providing the same seed for each run:

--order rand:1234

The seed is printed to the console with each run, so you can just copy it to the command. You can also just specify the seed, which RSpec will assume means you want to run with --order rand:

--seed 1234

Every time you run the suite with the same seed, the examples will run in the same “random” order.

Built-in matchers are all classes in rspec-expectations

The Matcher DSL in rspec-expectations makes it dead simple to define custom matchers that suit your domain. The problem is that it is several times slower than defining a class to do so. While this doesn’t make much difference when you have a custom matcher that you use a few dozen times (where talking hundredths of seconds here), it does make a difference if every single matcher invocation in your entire suite suffers this problem.

The short term fix is that all of the built-in matchers have been re-implemented as classes rather than using the DSL to declare them. This has the added benefit of making it easier to navigate the code and RDoc

Longer term, we’ll try to refactor the internals of the matcher DSL so that it generates a class at declaration time. Eventually.

Summing up

So that’s it. Nothing ground breaking. Nothing compatibility breaking. But some nice new features and improvements that will make your life just a little bit nicer when you upgrade. We’re doing a release candidate because enough changed internally that I want to give you time to try it out, so please, please do so! And please report any issues you’re having with this upgrade to:

• rspec-core
• rspec-expectations
• rspec-mocks
• rspec-rails

Assuming there are no significant issues, I’ll release 2.8 final within a week or two.

Happy spec’ing!

David

full changelog

• Bug fixes
• tell autotest the correct place to find the rspec executable

Just type rspec

With the the 2.7.0 release, if you keep all of your specs in the conventional spec directory, you don’t need to follow the rspec command with a path. Just type rspec.

If you keep your specs in a different directory, just set the --default_path option to that directory on the command line, or in a .rspec config file.

The rake task now lets Bundler manage Bundler

The RSpec::Core::RakeTask invokes the rspec command in a subshell. In recent releases, it assumed that you wanted it prefixed with bundle exec if it saw a Gemfile. We then added gemfile and skip_bundler options to the task, so you could manage this in different ways.

It turns out that Bundler manages this quite well without any help from RSpec. If you activate Bundler in the parent shell, via the command line or Bundler.setup, it sets environment variables that activate Bundler in the subshell with the correct gemfile.

The gemfile and skip_bundler options are therefore deprecated and have no effect.

Release Notes

rspec-core-2.7.0

full changelog

NOTE: RSpec’s release policy dictates that there should not be any backward incompatible changes in minor releases, but we’re making an exception to release a change to how RSpec interacts with other command line tools.

As of 2.7.0, you must explicity require "rspec/autorun" unless you use the rspec command (which already does this for you).

• Enhancements

  • Add example.exception (David Chelimsky)
  • --default_path command line option (Justin Ko)
  • support multiple --line_number options (David J. Hamilton)
    • also supports path/to/file.rb:5:9 (runs examples on lines 5 and 9)
  • Allow classes/modules to be used as shared example group identifiers (Arthur Gunn)
  • Friendly error message when shared context cannot be found (Sławosz Sławiński)
  • Clear formatters when resetting config (John Bintz)
  • Add xspecify and xexample as temp-pending methods (David Chelimsky)
  • Add --no-drb option (Iain Hecker)
  • Provide more accurate run time by registering start time before code is loaded (David Chelimsky)
  • Rake task default pattern finds specs in symlinked dirs (Kelly Felkins)
  • Rake task no longer does anything to invoke bundler since Bundler already handles it for us. Thanks to Andre Arko for the tip.
  • Add --failure-exit-code option (Chris Griego)

• Bug fixes

  • Include Rake::DSL to remove deprecation warnings in Rake > 0.8.7 (Pivotal Casebook)
  • Only eval let block once even if it returns nil (Adam Meehan)
  • Fix --pattern option (wasn’t being recognized) (David Chelimsky)
  • Only implicitly require "rspec/autorun" with the rspec command (David Chelimsky)
  • Ensure that rspec’s at_exit defines the exit code (Daniel Doubrovkine)
  • Show the correct snippet in the HTML and TextMate formatters (Brian Faherty)

rspec-expectations-2.7.0

full changelog

• Enhancements

  • HaveMatcher converts argument using to_i (Alex Bepple & Pat Maddox)
  • Improved failure message for the have_xxx matcher (Myron Marston)
  • HaveMatcher supports count (Matthew Bellantoni)
  • Change matcher dups Enumerable before the action, supporting custom Enumerable types like CollectionProxy in Rails (David Chelimsky)

• Bug fixes

  • Fix typo in have(n).xyz documentation (Jean Boussier)
  • fix safe_sort for ruby 1.9.2 (Kernel now defines <=> for Object) (Peter van Hardenberg)

rspec-mocks-2.7.0

full changelog

• Enhancements

  • Use __send__ rather than send (alextk)
  • Add support for any_instance.stub_chain (Sidu Ponnappa)
  • Add support for any_instance argument matching based on with (Sidu Ponnappa and Andy Lindeman)

• Changes

  • Check for failure_message_for_should or failure_message instead of description to detect a matcher (Tibor Claassen)

• Bug fixes

  • pass a hash to any_instance.stub. (Justin Ko)
  • allow to_ary to be called without raising NoMethodError (Mikhail Dieterle)
  • any_instance properly restores private methods (Sidu Ponnappa)

rspec-rails-2.7.0

full changelog

• Enhancments

  • ActiveRecord::Relation can use the =~ matcher (Andy Lindeman)
  • Make generated controller spec more consistent with regard to ids (Brent J. Nordquist)
  • Less restrictive autotest mapping between spec and implementation files (José Valim)
  • require 'rspec/autorun' from generated spec_helper.rb (David Chelimsky)
  • add bypass_rescue (Lenny Marks)
  • route_to accepts query string (Marc Weil)

• Internal

  • Added specs for generators using ammeter (Alex Rothenberg)

• Bug fixes

  • Fix configuration/integration bug with rails 3.0 (fixed in 3.1) in which fixure_file_upload reads from ActiveSupport::TestCase.fixture_path and misses RSpec’s configuration (David Chelimsky)
  • Support nested resource in view spec generator (David Chelimsky)
  • Define primary_key on class generated by mock_model("WithAString") (David Chelimsky)

The reported problem: ActiveSupport::JSON::Encoding::CircularReferenceError using doubles

This spec …

require 'spec_helper'

describe ListsController do
  let(:list) { double("List") }

  describe "GET 'index'" do
    let(:expected) { [{id: "1", name: "test"}] }

    before do
      list.stub(:id){ "1" }
      list.stub(:name){ "test" }
      List.stub(:select){ [ list ] }
    end

    it "should return the list of lists" do
      get :index, format: :json
      response.body.should == expected.to_json
    end
  end
end

… plus this implementation …

class ListsController < ApplicationController
  respond_to :json

  expose(:lists) { List.select("id, name") }

  def index
    respond_with(lists)
  end
end

… produces this failure:

  Failure/Error: get :index, format: :json
     ActiveSupport::JSON::Encoding::CircularReferenceError:
       object references itself

The deeper problem: this is a great example of when not to use stubs.

Here’s why: there are three incorrect assumptions hiding behind the stubs!

1. select takes an Array: List.select(["id","name"]), but the example stubs it incorrectly.
2. the id is numeric, but the example uses String.
3. the json is wrapped: {"list":{"id":1,"name":"test"}}, but the example doesn’t wrap it.

Even if the stubs were properly aligned with reality, the reason for the error is that respond_with(lists) eventually calls as_json on the list object, which, in this example, is an RSpec double that doesn’t implement as_json. We need to either use a stub_model (which does implement as_json), or explicitly stub it in the example:

list.stub(:as_json) { { list: {id: 1, name: "test"} } }

But I’d avoid stubs altogether in this case. Stubs are great for well defined (and understood) public APIs which are invoked by the code being specified. In this case, we’re stubbing an API (as_json) that is invoked by the Rails framework, not the code being specified. If the Rails framework ever changes how it renders json, this example would continue to pass, but it would be a false positive.

One possible remedy

Here’s how I’d approach this outside-in (based on my own flow, design preferences, and target outcomes. YMMV.)

Start with a request spec:

require 'spec_helper'

describe "Lists" do
  describe "GET 'index.json'" do
    it "returns the list of lists" do
      list = List.create!(name: "test")
      get "/lists.json"
      response.body.should == [{list: {id: list.id, name: "test"}}].to_json
    end
  end
end

This shows exactly what to expect, so when working on clients we can refer directly to this without having to dig into internals.

Run this and it fails with uninitialized constant List, so generate the list resource:

rails generate resource list name:string
rake db:migrate
rake db:test:prepare

Run it again and it fails with ActionView::MissingTemplate. Now we have a couple of choices. The purist view says “write a controller spec”, but some people say controller specs are unnecessary if there are already request specs (or cukes) as they just add duplication.

For me, the answer depends upon the complexity of the requirement as it compares to what we get for free from Rails. In this case, the only difference between the requirement and what Rails gives us for free is that we constrain the fields to id and name This is something we can implement in the model, so I’d just implement this very simple controller code and move on:

class ListsController < ApplicationController
  respond_to :json

  def index
    respond_with List.all
  end
end

Now the request spec fails with:

expected: "[{\"list\":{\"id\":1,\"name\":\"test\"}}]"
     got: "[{\"list\":{\"created_at\":\"2011-08-27T14:56:19Z\",\"id\":1,\"name\":\"test\",\"updated_at\":\"2011-08-27T14:56:19Z\"}}]"

We’re getting more key/value pairs than we want. I want the model responsible for constraining the keys in the json (Rails implements json transformations in the context of the model, so why shouldn’t we?), so I’d add a model spec:

require 'spec_helper'

describe List do
  describe "#as_json" do
    it "constrains keys to id and name" do
      list = List.new(:name => "things")
      list.as_json['list'].keys.should eq(%w[id name])
    end
  end
end

This fails with:

expected ["id", "name"]
     got ["created_at", "name", "updated_at"]

I expect to see created_at and updated_at, but I’m surprised (initially) to see that id is missing. Thinking this through, it makes sense because the example generates the list using new, so no id is generated. To get id to show up in the list of keys, we can use create instead of new, or we can explicitly set it. I’m going to go with setting the id explicitly to avoid the db hit, accepting the self-imposed leaky abstraction. It’s all trade-offs.

it "constrains fields to id and name" do
  list = List.new(:name => "things")
  list.id = 37
  list.as_json['list'].keys.should eq(%w[id name])
end

Now it fails with:

expected ["id", "name"]
     got ["created_at", "id", "name", "updated_at"]

Now we can implement the constraint:

class List < ActiveRecord::Base
  def as_json
    super({ only: %w[id name]})
  end
end

Now the model spec passes, but the request spec fails with:

ArgumentError:
  wrong number of arguments (1 for 0)

This is because the as_json implementation fails to honor the Rails API:

as_json(options = nil)

as_json is called by the Rails framework with an options hash. Had we done this without the request spec and weren’t aware of this information, we’d have a bunch of passing specs but the app would blow up. Hooray for testing at multiple levels!

So we add a new example to the model spec:

it "honors the submitted options hash" do
  list = List.new(:name => "things")
  list.id = 37
  list.as_json(:only => :name)['list'].keys.should eq(%w[name])
end

This fails with wrong number of arguments (1 for 0) as well, so now we adjust the model implementation:

def as_json(opts={})
  super({ only: %w[id name]}.merge(opts))
end

Now the model spec passes again, and so does the request spec! DONE!

The result is a very nice balance of clarity, speed (in spite of the one db hit in the request spec) and flexibility. Any new endpoints we add will get the same json representation because it is expressed in the model (heeding the principle of least surprise). The model spec not only specifies how the model should represent itself as json, but it helps to explain how the rails framework uses the model. All of this with no stubbing at all, and especially no stubbing of APIs our code isn’t invoking.

1. it helps you to install the correct gem versions
2. it constrains the load path to the correct gem versions at runtime

Assuming you’re using Bundler to constrain your runtime environment (which you are if you’re using Rails 3 defaults), then you are likely prefixing most shell commands with bundle exec.

We interrupt this post for an important update:

Two important pieces of information in the comments:

1. Prepending ./bin to your path exposes a serious security risk. Proceed with caution.
2. rvm >= 1.6.18 + bundler >= 1.0.5 removes the need for this altogether.

We now return you to our regularly scheduled post:

Here’s a little tip to help save you the prefix, without adding any aliases or functions to your environment.

bundle install --binstubs
export PATH=./bin:$PATH

bundle install --binstubs creates a bin directory at the root of your project, and fills it with Bundler-enabled wrappers for all of the executables installed by the gems listed in your Gemfile. This enables you to type bin/rake instead of bundle exec rake, for example, ensuring that the correct version of rake is loaded.

Now prepend ./bin to your path and you can just type rake.

• Bug fixes
  • Support exclusion filters in DRb. (Yann Lugrin)
  • Fix —example escaping when run over DRb. (Elliot Winkler)
  • Use standard ANSI codes for color formatting so colors work in a wider set of color schemes.

First, there are three distinct issues related to the rake release:

1. Backward-incompatibility

Rake 0.9 includes backward-incompatible changes. Per the changelog:

## Version 0.9.0

* *Incompatible* *change*: Rake DSL commands ('task', 'file', etc.)  are
  no longer private methods in Object.  If you need to call 'task :xzy' inside
  your class, include Rake::DSL into the class.  The DSL is still available at
  the top level scope (via the top level object which extends Rake::DSL).

This conflicts with the way Rails, among others, uses Rake, among others. The workaround recommended by @dhh is to constrain the rake version in the Gemfiles in your Rails applications:

gem "rake", "0.8.7"

This is a perfectly fine short term solution to keep your applications running, but it won’t be long before a gem that your Rails application depends on, either directly or through the transitive property of dependencies, is going to specify any of:

gemspec.add_dependency 'rake', '0.9.0'
gemspec.add_dependency 'rake', '>= 0.9.0'
gemspec.add_dependency 'rake', '~> 0.9.0'

When that happens, you’ll need to loosen the constraint in your app if you want to upgrade any of the gems downstream from the gem that introduces this dependency. This is not a big deal because you can control the situation directly in your own Gemfile in your own application.

Libraries are not applications

This advice should not, however, be applied to any gems that depend on Rake. Let’s say you’re using two gems that both provide Rake tasks and therefore depend on the rake gem. At some point the maintainer of gem aaa changes the constraint to "= 0.8.7", and the maintainer of gem bbb keeps a looser constraint: either ">= 0.8.7" or "~> 0.8.7". You upgrade to the new version of aaa and everything is fine because both constraints are satisfied by rake-0.8.7.

A little while down the road, the constraint in bbb changes to "~> 0.9.0". At this point you are unable to have the newest versions of aaa and bbb in the same application. This may not seem like a big deal because you can choose to not upgrade bbb at this point, but the further upstream the dependency (i.e. aaa depends on bbb, which depends on ccc), the more likely you are to be constrained in your upgrade choices.

In short, if you are maintaining a gem that applications or other gems depend on, you are doing end users a disservice by locking down any upstream dependency at one and only one version number.

Now here’s the catch: while some gem maintainers follow some sort of standard versioning and/or release policy, there are many that don’t. If you put in a looser version constraint on a gem whose maintainers introduce breaking changes in patch releases, you are also doing your users a disservice. More on this later.

2. Rake is used to run tasks that depend on Rake

Perhaps you’ve run into this interaction (or similar):

$ bundle install
$ rake db:migrate
You have already activated rake 0.9.0, but your Gemfile requires rake 0.8.7. Consider using bundle exec.

In this case, the application has an explicit dependency on rake-0.8.7, but rake-0.9.0 is installed in the shell environment. When you type rake xxx, Rubygems activates the 0.9.0 version (the newest version installed), and then tries to activate 0.8.7 when the app is running.

This is a catch 22 that we’ve been lulled into ignoring by the mere fact that there have not been any rake releases for a couple of years (rake-0.9.0 was released 2 years and 5 days after rake-0.8.7). We all expect to type rake xxx and have it just work. Why not? It’s worked thus far, right?

During the two years of rake-0.8.7, Bundler was born. You may remember that the Bundler team took a lot of heat during its early days. One of the complaints I remember was that people didn’t want to have to type bundle exec to run a rake task. The result is that pretty much all apps that use Bundler and Rake have this in their Rakefiles:

require 'rubygems'
require 'bundler'
Bundler.setup

This enables us to type rake xxx and let Bundler manage loading every other gem besides rake, which is already loaded by Rubygems. So now when we find both rake-0.8.7 and 0.9.0 in our gem environment, and the app we’re working with depends explicitly on 0.8.7, we have (at least) three options:

a. Tell bundler to install the rake command PROJECT_ROOT/bin

bundle install --binstubs

Now you can run this

bin/rake xxx

b. Explicitly run bundle exec

bundle exec rake

In either of the first two options, Bundler controls the activation of the rake gem for you, which allows it to put the correct version on the $LOAD_PATH.

c. Just remove 0.9 from the current gem environment

gem uninstall rake

This only works if you’re using an isolated gemset for the current project (e.g. using rvm) or you simply don’t need rake-0.9.0 on your system. It also is not a very reliable way to deal with this if you have any sort of automated build or deployment system that is installing gems into a shared gem environment on the build or production servers.

The real problem here is not that we have to type a different command on the command line. We humans can adapt and get used to doing that. The deeper problem is that there are countless automation scripts out in the wild that depend on rake xxx. In order to support both versions of Rake, they will all have to be changed to use one of the first two solutions noted above. The cost of this is no small chunk of change, but it is nobody’s fault but our own for failing to recognize the cyclical nature of using a versioned tool to run applications that might require a different version.

3. Not all gems expose their dependencies in a way that Bundler or Rubygems can control them

On my team at DRW, we tried to constrain our rake dependencies to 0.8.7 as a temporary measure, but each time we installed into a new gem environment we found that rake-0.9.0 was being installed. It turned out that a gem we depended on was installing rake through a back door, and with no version constraint at all. The result was that neither Bundler nor Rubygems had any control over this installation relative to our application (Bundler told Rubygems to install this gem, and this gem silently installed rake). And, to make things more confusing, Bundler reported that it was installing rake-0.8.7 and said nothing about 0.9.0.

The maintainer of that gem released new versions right away, so that issue is now resolved, but it’s entirely possible that other gems you’re using are doing the same (or similar). Just something to keep your eye out for.

What can we learn from all of this?

One issue this exposes is a lack of common understanding and agreement about how to manage releases and dependencies. The Rubygems Rational Versioning policy and Semantic Versioning are both very sound approaches that share a common scheme for version numbers:

A version has three parts: major, minor, and patch. For example, release 3.0.0 is a major release because the first number was incremented from 2 to 3, 3.2.0 is a minor release because the second number was incremented from 1 to 2, and 3.2.1 is a patch release because the third number was incremented from 0 to 1. Both specs state the following:

1. Patch releases (3.2.1) should only include bug fixes and internal implementation changes.
2. Minor releases (3.2.0) can include bug fixes, internal changes, and new features, but no breaking changes.
3. Major releases (3.0.0) can include bug fixes, internal changes, new features, and breaking changes.

If everybody adhered to either policy, we’d all be able to declare our gem dependencies like this:

spec.add_dependency "foo", ">= 2.3", "< 3.0"

… or the following, oft misunderstood, shortcut for same:

spec.add_dependency "foo", "~> 2.3"

This tells Rubygems to install the newest version that is >= 2.3.0, trusting that no version 2.y.x will include breaking changes.

RSpec

I’ll confess that I didn’t adhere to either approach with RSpec until the rspec-2.0.0 release, last October. I knowingly introduced breaking changes in the 1.x series and RSpec likely lost the confidence of a fair sum of users during that time.

The good news, vis a vis RSpec, is that we’ve been following Rubygems Rational Versioning since the rspec-2.0 release. While we’ve had a couple of regressions in the process (followed swiftly by patch releases that addressed them), there has been only one intentionally breaking change, and that was related to integration with another library. That change was announced, documented, and I don’t recall seeing any issues reported related to it.

We’re not doing SemVer yet because it is more strict than RRV, and RSpec does not currently meet all of its criteria. I do hope, however, to have RSpec on SemVer before the year is out.

This all sounds great, but …

… the reality is that getting every gem developer to commit to RRV or SemVer is very unlikely. What those of us who do can do, however, is try to provide a balance of flexibility and safety when we declare upstream dependencies. The rspec-expectations gem, for example, declares the following runtime dependency:

diff-lcs ~> 1.1.2

This expresses an opinion that it is safe for your application (that depends on rspec-expectations) to depend on any 1.1.x version of diff-lcs greater than or equal to 1.1.2, but it is not safe to depend on 1.2.0. While this provides a high degree of safety, it also provides low flexibility: if any other gem your app depends on depends on diff-lcs-1.2 in the future (not likely, since 1.1.2 was released in 2004, but that’s besides the point), you won’t be able to use it with the current release of rspec-expectations, even if the diff-lcs-2.2 release does not include any breaking changes.

If diff-lcs was still under regular maintenance, and it’s maintainers were committed to RRV or SemVer, then rspec-expectations would be able to use this dependency instead:

diff-lcs ~> 1.2

This would provide significantly more flexibility in rspec-expectations’s ability to play nice with other gems that also depend on diff-lcs in the same applciation over a longer period of time.

Note that every gem page on rubygems.org now includes a recommendation to use the pessamistic constraint using a three-part version number (e.g. rake ~> 0.9.0). As just discussed, this provides safety, but lacks long term flexibility.

Depending on rake

So what should maintainers of gems that depend on rake do now? The likelihood is that some end users will constrain their applications to rake 0.8.7, and others will constrain them to = 0.9.0, ~> 0.9.0, or >= 0.9.0. Unless Jim Weirich announces that rake will follow RRV or SemVer, we have to allow for the possibility that rake 0.10.0 will introduce new breaking changes. In this case, I think the responsible thing to do is make sure our gems work with both rake-0.8 and 0.9, and specify the dependency like this:

spec.add_runtime_dependency 'rake', '>= 0.8.7', '< 0.10'

Trusting that no rake 0.9.x version will introduce breaking changes, this provides the greatest flexibility to end users without exposing them to the risk of breaking changes in rake-0.10.0.

Feedback

I’m curious to hear what you think about all of this. Do you think this all makes sense? Do you think I’m over or understating the importance, complexity, or severity of these issues? Do you have a different approach to recommend in moving forward? I look forward to your feedback.

rspec-rails-2.6.1 / 2011-05-25

full changelog

• Bug fixes
  • fix controller specs with anonymous controllers with around filters
  • exclude spec directory from rcov metrics (Rodrigo Navarro)
  • guard against calling prerequisites on nil default rake task (Jack Dempsey)