Riot

A fast, expressive and concise unit-testing framework.

Installation

Add Gemcutter to your gem sources:

sudo gem sources -a http://gemcutter.org

Then, simply install the Riot gem like so:

sudo gem install riot

Usage

In contrast to other popular Ruby testing frameworks such as Test::Unit, Shoulda and RSpec, Riot does not run a setup and teardown sequence before and after each test. This speeds up the test runs quite a bit, but also puts restrictions on how you write your tests. In general, you should avoid mutating any objects under test.

In Riot, tests reside in contexts. Within these, a topic object is defined through a setup block. The actual assertions are then made with assert.

context "An Array" do
  setup { Array.new }
  asserts("is empty") { topic.empty? }
end

As you can see, the setup block doesn't use any instance variables to save the object under test -- rather, the return value of the block is used as the topic. This object can then be accessed in the assertions using the topic attribute.

Furthermore, assertions need only return a boolean; true indicates a pass, while false indicates a fail.

Contexts can also be nested; the setup blocks are executed outside-in before.

context "An Array" do
  setup { Array.new }

  context "with one element" do
    setup { topic << "foo" }
    asserts("is not empty") { !topic.empty? }
    asserts("returns the element on #first") { topic.first == "foo" }
  end
end

Using assertion macros

Macros greatly simplify a lot of assertions by capturing common practises, e.g. comparing some value using the == operator. They work by calling the macro method on the return value of asserts:

asserts("#first") { topic.first }.equals("foo")

Other macros are available; for a complete overview, see Riot::AssertionMacro.

A common pattern is to make assertions on the return value of some attribute or method on the topic -- to simplify this, we have provided an easy to use shorthand. Simply give a Symbol as the first argument to asserts and leave out the block.

asserts(:first).equals("foo")

If you're like me, you like to write a bunch of failing tests for a context and then make them pass. This can easily be done by simply calling an asserts or should command with no block returning the actual value.

asserts("something special")
should("do something special")

Both of the above tests will fail. You can use this similar to a should_eventually. The difference is that should_eventually is not technically a failure and will therefore be ignored in time by (based on my experience). The above two blocks will actually show up as failures and should hopefully drive you to making them pass.

Reading Riot's output

Riot can output the test results in several ways, the default being story reporting. With this reporter, the output looks like the following:

An Array
  + asserts is empty
An Array with one element
  + asserts is not empty
  + asserts returns the element on #first

3 passes, 0 failures, 0 errors in 0.000181 seconds

The various shorthands and macros are built in a way that ensures expressive and specific feedback, e.g. the assertion

asserts(:full_name).matches(/^\w+ \w+$/)

yields the output

+ asserts #full_name matches /^\w+ \w+$/

Testing Rack application

Rack applications can easily be tested using Riot::Rack, which integrates Rack::Test into Riot.

require 'riot'
require 'riot/rack'

context "HelloWorldApp" do
  # Specify your app using the #app helper. If you don't specify
  # one, Riot::Rack will recursively look for a config.ru file.
  app { HelloWorldApp }

  # You can use all the Rack::Test helpers in the setup blocks.
  setup { get '/' }

  # You can access the response directly.
  asserts(:status).equals(200)
  asserts(:body).equals("Hello, World!")
end

Contributing

Riot is still in its infancy, so both the internal and external API may change radically. That being said, we would love to hear any thoughts and ideas, and bug reports are always welcome. We hang out in #riot on irc.freenode.net.

The code is hosted on GitHub, and can be fetched with Git by running:

git clone git://github.com/thumblemonks/riot.git

License

Riot is released under the MIT license. See MIT-LICENSE.