Kelp

Kelp is a collection of helpers that makes it easier to write step definitions for Cucumber. The Kelp gem is hosted on Rubygems, so you can install it with:

$ gem install kelp

The name "Kelp" is a contraction of "Cuke Helpers". It was chosen because it's short, easy to remember, and is in keeping with the theme of greenish plants. Kelp is licensed under the MIT License.

Documentation is available on rdoc.info. Please use the issue tracker to report any bugs or feature requests. Visit the #kelp channel on irc.freenode.net to chat.

Motivation

Kelp was developed as an attempt to get away from the bad habit of nesting steps inside one another. While Cucumber does allow this behavior, it is frowned upon by much of the Cucumber community. It was also partly motivated by a desire to move away from imperative steps, toward a more declarative style. Some of Capybara's methods were perceived as being too low-level, especially when it comes to filling in or verifying several different fields in a form, or checking the presence or absence of multiple strings or regular expressions.

As of version 1.1.0, cucumber-rails no longer provides a generator for web_steps.rb; since Kelp does provide such a generator, it may serve the niche market of cucumber-rails users who preferred to use the imperative step definitions that it provided. Kelp's intent is not to encourage this behavior; nearly all of the imperative steps it provides are one-liners, which in many cases are more succinct and readable than the step definition that wraps them.

It is this developer's opinion that imperative web_steps.rb-style steps can be the easiest route to a working Cucumber scenario, but that they can also be a fast track to unmaintainability. Consider them a starting point; the baby steps you might take when writing your first few scenarios, before you discover the higher-level declarative steps that need to be reusably encapsulated.

Usage

To use Kelp's helpers in your Cucumber step definitions, simply require the helper module you're interested in:

require 'kelp/visibility'

Then add the relevant modules to Cucumber's World:

World(Kelp::Visibility)

Or, to include all available helpers:

require 'kelp/attribute'
require 'kelp/checkbox'
require 'kelp/dropdown'
require 'kelp/field'
require 'kelp/navigation'
require 'kelp/scoping'
require 'kelp/visibility'

World(Kelp::Attribute)
World(Kelp::Checkbox)
World(Kelp::Dropdown)
World(Kelp::Field)
World(Kelp::Navigation)
World(Kelp::Scoping)
World(Kelp::Visibility)

Many of the provided helpers are designed to make it easier to do things you might otherwise be tempted to do with nested step definitions. For example, if you need to verify the presence of several text strings on a webpage, you might have a step definition like this:

Then /^I should see the login page$/ do
  Then %{I should see "Welcome"}
  And %{I should see "Thanks for visiting"}
  And %{I should see "Login"}
end

Using the provided helper method should_see, you can do this instead:

Then /^I should see the login page$/ do
  should_see "Welcome"
  should_see "Thanks for visiting"
  should_see "Login"
end

Or even this:

Then /^I should see the login page$/ do
  should_see [
    "Welcome",
    "Thanks for visiting",
    "Login"
  ]
end

Following links, filling in fields, and pressing buttons can all be easily done with Ruby code instead of nested steps. Thus this:

When %{I follow "Login"}
And %{I fill in "Username" with "skroob"}
And %{I fill in "Password" with "12345"}
And %{I press "Log me in"}

translates to this:

follow "Login"
fill_in_fields \
  "Username" => "skroob",
  "Password" => "12345"
press "Log me in"

Several methods also accept keywords to define the scope of an action. For instance, if you want to look within an element with id="greeting"`, do:

should_see "Welcome", :within => "#greeting"

At the moment, the :within keyword is the only accepted scope; the locator you pass to this should be in whatever format your Capybara.default_selector is set to. Other keywords like :before or :after may be supported in future revisions.

See the kelp documentation. for more information.

Rails generator

Kelp provides a generator for Rails projects, which writes step definitions to features/step_definitions/web_steps.rb. This file provides all of the same step definitions formerly provided by cucumber-rails, with several enhancements. If you have made customizations to your web_steps.rb, they will be overwritten! Consider yourself warned.

To generate web_steps.rb, run this for Rails 2.x:

$ script/generate kelp

Or this for Rails 3.x:

$ rails generate kelp:steps

Note: If you are upgrading from a version of Kelp prior to 0.1.9, you should remove kelp_steps.rb from your features/step_definitions directory; these are obsolete, and conflict with the newer step definitions in web_steps.rb.

Development

If you'd like to hack on Kelp, first fork the repository, then clone your fork:

$ git clone git://github.com/your_username/kelp.git

Install bundler:

$ gem install bundler

Then install Kelp's dependencies:

$ cd /path/to/kelp
$ bundle install

It's a good idea to use RVM with a new gemset to keep things tidy.

If you make changes that you'd like to share, push them into your Kelp fork, then submit a pull request.

Testing

Kelp comes with a Rakefile, so you can run the RSpec tests and generate an rcov coverage report via:

$ rake spec

This will write an HTML report to coverage/index.html. Finally, there are some Cucumber self-tests included, mainly for testing the web_steps.rb file used by the Rails generator. Run via:

$ rake cucumber

This self-test includes high-level scenarios that exercise more detailed scenarios in examples/sinatra_app/features, ensuring that the generated step definitions perform as expected.

Future plans

• Support Webrat

Copyright

The MIT License

Copyright (c) 2010 Eric Pierce

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.