Turnip is a Gherkin extension for RSpec. It allows you to write tests in Gherkin and run them through your RSpec environment. Basically you can write cucumber features in RSpec.

Install the gem

gem install turnip

Or add it to your Gemfile and run bundle.

group :test do
  gem "turnip"
end

Now edit the .rspec file in your project directory (create it if doesn't exist), and add the following line:

-r turnip/rspec

• Source hosted at GitHub.
• Please direct questions, discussion or problems to the mailing list. Please do not open an issue on GitHub if you have a question.
• If you found a reproducible bug, open a GitHub Issue to submit a bug report.
• Please do not contact any of the maintainers directly, unless you have found a security related issue.

Pull requests are very welcome (and even better than bug reports)! Please create a topic branch for every separate change you make.

• Support Ruby 2.5 or higher
• Does not support Ruby (or does not work) 2.4.X or earlier

In accordance with the RSpec support policy jnicklas#158 (comment)

• Support RSpec 3.x the latest or one version before
• Does not support two version before the latest or earlier
• Does not work on RSpec 2 or earlier

Example If the latest version is 3.5.x:

• Support 3.5.x
• Support 3.4.x
• Does not support (or does not work) 3.3.x or earlier

Add a feature file anywhere in your spec directory:

# spec/acceptance/attack_monster.feature
Feature: Attacking a monster
  Background:
    Given there is a monster

  Scenario: attack the monster
    When I attack it
    Then it should die

Now you can run it just like you would run any other rspec spec:

rspec spec/acceptance/attack_monster.feature

It will automatically be run if you run all your specs with rake spec or rspec spec.

Yes, that's really it.

You can define steps on any module:

module MonsterSteps
  step "there is a monster" do
    @monster = Monster.new
  end
end

You can now include this module in RSpec:

RSpec.configure { |c| c.include MonsterSteps }

Steps are implemented as regular Ruby methods under the hood, so you can use Ruby's normal inheritance chain to mix and match steps.

Since Turnip runs atop RSpec, it can utilize RSpec's built-in before and after hooks. To run a hook for all features, specify a global hook with type set to :feature:

config.before(:type => :feature) do
  do_something
end
config.after(:type => :feature) do
  do_something_else
end

You can also limit this to a tag by specifying the tag in the argument to before or after:

config.before(:some_tag => true) do
  do_something
end

Turnip has a special module called Turnip::Steps, which is automatically included in RSpec. If you add steps to this module, they are available in all your features. As a convenience, there is a shortcut to doing this, just call step in the global namespace like this:

step "there is a monster" do
  @monster = Monster.new
end

Note that unlike Cucumber, Turnip does not support regexps in step definitions. You can however use placeholders in your step definitions, like this:

step "there is a monster called :name" do |name|
  @monster = Monster.new(name)
end

You can now put values in this placeholder, either quoted or not:

Given there is a monster called Jonas
And there is a monster called "Jonas Nicklas"

You can also specify alternative words and optional parts of words, like this:

step "there is/are :count monster(s)" do |count|
  @monsters = Array.new(count) { Monster.new }
end

That will match both "there is X monster" or "there are X monsters".

You can also define custom step placeholders. More on that later.

Since steps are defined on modules, you can pick and choose which of them are available in which feature. This can be extremely useful if you have a large number of steps, and do not want them to potentially conflict.

If you had some scenarios which talk to the database directly, and some which go through a user interface, you could implement it as follows:

module InterfaceSteps
  step "I do it" do
    ...
  end
end

module DatabaseSteps
  step "I do it" do
    ...
  end
end

RSpec.configure do |config|
  config.include InterfaceSteps, :interface => true
  config.include DatabaseSteps, :database => true
end

Turnip turns tags into RSpec metadata, so you can use RSpec's conditional include feature to include these steps only for those scenarios tagged the appropriate way. So even though the step is named the same, you can now use it in your feature files like so:

@interface
Scenario: do it through the interface

@database
Scenario: do it through the database

Be careful though not to tag a feature with both @interface and @database in this example. Since steps use the Ruby inheritance chain, the step which is included last will "win", just like any other Ruby method. This might not be what you expect.

Since this pattern of creating a module and including it for a specific tag is very common, we have created a handy shortcut for it:

steps_for :interface do
  step "I do it" do
    ...
  end
end

Check out features/alignment_steps.rb

for an example.

Turnip automatically loads your spec_helper file. From there you can place your steps wherever you want, and load them however you like. For example, if you were to put your steps in spec/steps, you could load them like this:

Dir.glob("spec/steps/**/*steps.rb") { |f| load f, true }

Before loading your spec_helper, Turnip also tries to load a file called turnip_helper where you can setup anything specific to your turnip examples. You might find it beneficial to load your steps from this file so that they don't have to be loaded when you run your other tests.

If you use Turnip with rspec-rails v3.x, most configuration written to rails_helper.rb but not spec_helper.rb. So you should write to turnip_helper like this:

require 'rails_helper'

Then you can write configuration to rails_helper to load your steps.

Since steps are Ruby methods you can call them like other Ruby methods. However, since the step description likely contains spaces and other special characters, you will probably have to use send to call the step:

step "the value is :num" do |num|
  @value = num
end

step "the value is twice as much as :num" do |num|
  send "the value is :num", num * 2
end

If you use the second step, it will call into the first step, sending in the doubled value.

Sometimes you will want to call the step just like you would from your feature file, in that case you can use the step method:

step "the value is :num" do |num|
  @value = num
end

step "the value is the magic number" do
  step "the value is 3"
end

You can mark an existing method as a step. This will make it available in your Turnip features. For example:

module MonsterSteps
  def create_monster(name)
    @monster = Monster.new(:name => name)
  end
  step :create_monster, "there is a monster called :name"
end

Do you want to be more specific in what to match in your step placeholders? Do you find it bothersome to have to constantly cast them to the correct type? Turnip supports custom placeholders to solve both problems, like this:

step "there are :count monsters" do |count|
  count.times { Monster.new(name) }
end

placeholder :count do
  match /\d+/ do |count|
    count.to_i
  end

  match /no/ do
    0
  end
end

You would now be able to use these steps like this:

Given there are 4 monsters
Given there are no monsters

Placeholders can extract matches from the regular expressions as well. For example:

placeholder :monster do
  match /(blue|green|red) (furry|bald) monster/ do |color, hair|
    Monster.new(color, hair)
  end
end

These regular expressions must not use anchors, e.g. ^ or $. They may not contain named capture groups, e.g. (?<color>blue|green).

Note that custom placeholders can capture several words separated by spaces and without surrounding quotes, e.g.:

step 'there is :monster in the loft' do |monster|
  # call 'Given there is green furry monster in the loft',
  # :monster will capture 'green furry moster'
end

E.g. Common should / should not steps:

step 'I :whether_to see :text' do |positive, text|
  expectation = positive ? :to : :not_to
  expect(page.body).send expectation, eq(text)
end

placeholder :whether_to do
  match /should not/ do
    false
  end

  match /should/ do
    true
  end
end

Then, it is possible to call the following steps:

Then I should see 'Danger! Monsters ahead!'
 And I should not see 'Game over!'

You can also define custom placeholder without specific regexp, that matches the same value of the default placeholder like this:

placeholder :monster_name do
  default do |name|
    Monster.find_by!(name: name)
  end
end

Turnip also supports steps that take a table as a parameter similar to Cucumber:

Scenario: This is a feature with a table
  Given there are the following monsters:
    | Name    | Hitpoints |
    | Blaaarg | 23        |
    | Moorg   | 12        |
  Then "Blaaarg" should have 23 hitpoints
  And "Moorg" should have 12 hitpoints

The table is a Turnip::Table object which works in much the same way as Cucumber's Cucumber::Ast::Table objects.

E.g. converting the Turnip::Table to an array of hashes:

step "there are the following monsters:" do |table|
  @monsters = {}
  table.hashes.each do |hash|
    @monsters[hash['Name']] = hash['Hitpoints'].to_i
  end
end

or the equivalent:

step "there are the following monsters:" do |table|
  @monsters = {}
  table.rows.each do |(name, hp)|
    @monsters[name] = hp.to_i
  end
end

Turnip mark a scenario as pending when steps in the scenario is not implemented. If you sets raise_error_for_unimplemented_steps as true, turnip will mark a scenario as fail.

It defaults to false, you can change it by following configuration:

RSpec.configure do |config|
  config.raise_error_for_unimplemented_steps = true
end

You would be able to use substitution that can be used to DocString and Table arguments in Scenario Outline like Cucumber:

Scenario Outline: Email confirmation
  Given I have a user account with my name "Jojo Binks"
  When an Admin grants me <Role> rights
  Then I should receive an email with the body:
    """
    Dear Jojo Binks,
    You have been granted <Role> rights.  You are <details>. Please be responsible.
    -The Admins
    """
  Examples:
    |  Role     | details                                         |
    |  Manager  | now able to manage your employee accounts       |
    |  Admin    | able to manage any user account on the system   |

Just require turnip/capybara in your spec_helper. You can now use the same tags you'd use in Cucumber to switch between drivers e.g. @javascript or @selenium. Your Turnip features will also be run with the :type => :feature metadata, so that Capybara is included and also any other extensions you might want to add.

(The MIT License)

Copyright (c) 2011-2012 Jonas Nicklas

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.