Anti-patterns

There are several anti-patterns, which we will describe here. We will also give you hints on how to avoid them!

Feature-coupled step definitions

Feature-coupled step definitions are step definitions that can’t be reused across features or scenarios.

This may lead to an explosion of step definitions, code duplication, and high maintenance costs.

Example

An imaginary résumé application could have the following Feature and Step Definition files:

features/
+--edit_work_experience.feature
+--edit_languages.feature
+--edit_education.feature
+--steps/
   +--edit_work_experience_steps.java
   +--edit_languages_steps.java
   +--edit_education_steps.java
features/
+--edit_work_experience.feature
+--edit_languages.feature
+--edit_education.feature
+--steps/
   +--edit_work_experience_steps.js
   +--edit_languages_steps.js
   +--edit_education_steps.js
features/
+--edit_work_experience.feature
+--edit_languages.feature
+--edit_education.feature
+--steps/
   +--edit_work_experience_steps.rb
   +--edit_languages_steps.rb
   +--edit_education_steps.rb

The edit_work_experience.feature could have the following Scenario:

Scenario: add description
  Given I have a CV and I'm on the edit description page
  And I fill in "Description" with "Cucumber BDD tool"
  When I press "Save"
  Then I should see "Cucumber BDD tool" under "Descriptions"

The could be implemented like this:

    @Given("^I have a CV and I'm on the edit description page$")
    public void I_have_a_CV_and_Im_on_the_edit_description_page() {
        Employee employee = new Employee("Sally");
        employee.createCV();
    }
var { Given } = require('cucumber');

Given(/^I have a CV and I'm on the edit description page$/, function () {
  this.employee = new Employee('Sally');
  this.employee.createCV();
});
Given /I have a CV and I'm on the edit description page/ do
  @employee = Employee.create!(name: 'Sally')
  @employee.create_cv
  visits("/employees/#{@employee.id}/descriptions/new")
end

How to decouple steps & step definitions

  • Organise your steps by domain concept.

  • Use domain-related names (rather than feature- or scenario-related names) for your step & step definition files.

Conjunction steps

From the online Merriam-Webster dictionary:

con·junc·tion: an uninflected linguistic form that joins together sentences, clauses, phrases, or words.

Don’t use steps that combine a bunch of different things. This makes steps too specialised, and hard to reuse. Cucumber has built-in support for conjunctions (And, But) for a reason!

Example

Given I have shades and a brand new Mustang

How to split conjunction steps

Given I have shades
And I have a brand new Mustang

Support for conjunction steps

Sometimes you may want to combine several steps into one, to make your scenarios easier to read. For instance, if you need to set up several preconditions in your Given state.

The best way to achieve composition and reuse, is to use the features of your programming language. If you want to combine several actions into one step, extract individual (helper) methods and call these methods from your step definition.

To make your life easier, strive to keep your steps atomic as much as possible.

More information

For more information on anti-patterns, see Cucumber Anti-Patterns (blog).


You can help us improve this documentation. Edit this page.