cucumber Gherkin Syntax The Basics

Example

This example will go over the basic structure of a Cucumber feature file in Gherkin. Feature files use several keywords in the basic syntax.

Lets look at the basic keywords:

• Feature: this keyword signifies that what follows is a basic description or name of the feature being tested or documented.
• Scenario: this keyword represents the name or basic description of a particular scenario testing the feature.
• Given this keyword represents a given step, or precondition that is assumed before continuing. In the Arrange, Act, Assert paradigm, given represents "Arrange".
• When this keyword represents a when step, or the behavior that is to be asserted against. In the Arrange, Act, Assert paradigm, given represents "Act".
• Then this keyword represents a then step, or in other words, the step in which a behavior's result is validated. In the Arrange, Act, Assert paradigm, given represents "Assert".
• And This keyword is used in conjunction with any of the keywords above. If you have two given statements, instead of explicitly calling Given twice, you can say, " Given A And B".
• But This keyword is used in conjunction Given, When and Then to signify that something should not happen. Then A But not B.

All keywords must be on a new line and must be the first word on a new line in order to be recognized by the Gherkin parser. The Feature and Scenario keywords must have a colon immediately after, as expressed in the example below. Given, When, Then, and And do not require a colon.

In addition to keywords, you can write descriptions and comments. Descriptions occur after the keyword but on the same line, where as comments occur on lines underneath the keywords. When writing Feature comments, it is customary to provided explicit rules outlining edges and conditions that lead to different outcomes of behaviors.

Feature: Product Login
    As a user, I would like to be able to use my credentials to successfully 
    login. 
    
    Rules:
    - The user must have a valid username
    - The user must have a valid password
    - The user must have an active subscription 
    - User is locked out after 3 invalid attempts
    - User will get a generic error message following 
      login attempt with invalid credentials 

    Scenario: The user successfully logs in with valid credentials 
        This scenario tests that a user is able to successfully login
        provided they enter a valid username, valid password, and 
        currently have an active subscription on their account. 

        Given the user is on the login page
        When the user signs in with valid credentials
        Then the user should be logged in