cucumber Getting started with cucumber A Cucumber feature

Example

Cucumber uses Gherkin syntax to describe your software's behaviors in structured natural language.

As such Cucumber is not a test framework (a common misunderstanding), but a system documentation framework, not very different from others like Use Case Scenario. The common misunderstanding is due to the fact Cucumber documentation can be automated in order to ensure it reflects the real system behavior.

A Cucumber documentation suite is composed of Features, each describing a feature of your software, written in Gherkin and hosted in its own file. By organizing those files into a directory structure you can group and organize features:

• banking/
  • withdrawal.feature
  • atm.feature
  • personal-loan.feature
• trading/
  • portfolio.feature
  • intraday.feature
• mortgage/
  • evaluation.feature
  • accounting.feature

Each Feature is a plain text file composed by an optional, unstructured, purely informational introductory section and one or more Scenarios, each one representing a usage condition or use case.

Example:

Feature: Documentation
As a StackOverflow user or visitor
I want to access the documentation section
    
    Scenario: search documentation on Stack Overflow
        Given I am on StackOverflow
        And I go to the Documentation section
        When I search for "cucumber"
        And I follow the link to "cucumber"
        Then I should see documentation for "cucumber"

Each line beginning with Given, When, And, But or Then is called a Step. Any step can begin with any of those words regardless of order, but it is conventional to use them in the most natural way possible.

Features can also be organized via Tags, annotations the editor can put on a Feature or a Scenario to further categorize it.

Executability of a Feature is achieved via glue code which can be written in many different languages (Java, Ruby, Scala, C/C++): each Step is matched against the glue code in order to identify Step Definitions (commonly abbreviated to StepDef) via regular expressions.

Every Step can have only one associated Step Definition.

When a Feature is executed each composing Scenario is executed, meaning each StepDef matching the Steps in every Scenario gets executed.