RSpec-illustrate Gem Version

A plugin to RSpec and YARD that allows you to define illustrative objects in your examples that will be forwarded to the output formatter. The results can be imported into YARD, which makes your generated specs and documentation more readable, illustrative, and explanatory.

Source code at

Documentation at


Add this line to your application's Gemfile:

gem 'rspec-illustrate'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rspec-illustrate


Within an example you use the illustrate statement to define an object that will be passed to the output formatter. You can also provide additional options if you want to set a label or define when the formatter should write the illustration (e.g. omit if the example fails, etc.)

Given the file ./spec/array_spec.rb:

require 'rspec/illustrate'

describe Array do
  describe "#sort" do
    it "should sort the array" do
      given = [3, 1, 2]
      expected = [1, 2, 3]
      actual = given.sort

      illustrate given, :label=>"Given the array"
      illustrate expected, :label=>"After sort it looks like this"
      illustrate actual, :show_when_passed=>false

      expect(actual).to eq(expected)

You execute RSpec with a formatter that takes the illustrations into consideration, i.e.:

$ rspec -f RSpec::Formatters::IllustratedDocumentationFormatter

The output would be something like this:

    should sort the array
    --- Given the array ---
    [3, 1, 2]
    --- After sort it looks like this ---
    [1, 2, 3]

Import test results and illustrations into YARD

RSpec-Illustrate comes with a template for YARD and an RSpec formatter that outputs a specific HTML format that the template can import.

To create the test report you have to execute RSpec with the specific formatter. You need to add the following to your Rakefile:

require "rspec/core/rake_task" do |t|
  t.rspec_opts = "--format RSpec::Formatters::YARD --out ./doc/api.rspec"

Keep in mind that the file must end with .rspec in order for the template to understand it's an RSpec output file. You load the template by invoking require rspec/illustrate/yard and you import it by giving it to YARD as a normal input file. Add the following to your Rakefile:

require 'yard'
require 'rspec/illustrate/yard' do |t|
    t.files   = ['lib/**/*.rb', 'doc/api.rspec']
task :doc => [:spec]

You can also include it as an extra file if you want to view it as a complete test report (it is HTML after all). Simply add it to the list of extra files by adding it after the - sign:

require 'yard'
require 'rspec/illustrate/yard' do |t|
    t.files   = ['lib/**/*.rb', 'doc/api.rspec', '-', 'doc/api.rspec']
task :doc => [:spec]


After checking out the repo, run bin/setup to install dependencies.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release to create a git tag for the version, push git commits and tags, and push the .gem file to


  1. Fork it ( )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request