majiayu000 Cucumber Fundamentals
Master the core concepts of Cucumber and Gherkin for behavior-driven development.
Gherkin Syntax
Use the Given-When-Then structure for scenarios:
Feature: User Authentication
As a user
I want to log in to the application
So that I can access my account
Scenario: Successful login with valid credentials
Given I am on the login page
When I enter valid credentials
And I click the login button
Then I should be redirected to the dashboard
And I should see a welcome message
Keywords
- Feature: High-level description of a software feature
- Scenario: Concrete example illustrating a business rule
- Given: Context or preconditions
- When: Action or event
- Then: Expected outcome
- And/But: Connect multiple steps
- Background: Common preconditions for all scenarios
- Scenario Outline: Template for multiple examples
- Examples: Data table for Scenario Outline
Feature Files
Structure feature files logically:
Feature: Shopping Cart Management
In order to purchase products
As a customer
I want to manage items in my shopping cart
Background:
Given I am logged in as a customer
And my shopping cart is empty
Scenario: Add product to cart
When I add a "Laptop" to my cart
Then my cart should contain 1 item
And the cart total should be "$999.99"
Scenario: Remove product from cart
Given I have a "Laptop" in my cart
When I remove the "Laptop" from my cart
Then my cart should be empty
And the cart total should be "$0.00"
Scenario Outlines
Use data tables for parameterized tests:
Scenario Outline: Login with different user types
Given I am on the login page
When I log in as "<user_type>"
Then I should see the "<dashboard>" dashboard
And I should have "<permissions>" permissions
Examples:
| user_type | dashboard | permissions |
| admin | Admin | full_access |
| user | User | limited_access |
| guest | Public | read_only |
Tags
Organize and filter scenarios with tags:
@smoke @authentication
Scenario: User login
Given I am on the login page
When I enter valid credentials
Then I should be logged in
@wip
Scenario: Password reset
Given I am on the password reset page
# Work in progress
Best Practices
- Write declarative scenarios - Focus on what, not how
- Keep scenarios independent - Each scenario should stand alone
- Use domain language - Write in business terms, not technical implementation
- One scenario, one behavior - Test one thing at a time
- Avoid UI details in Given/When/Then - Stay at business logic level
Example: Good vs Bad Scenarios
❌ Bad (imperative, implementation-focused):
Scenario: Update user profile
Given I navigate to "http://example.com/profile"
When I find the element with id "firstName"
And I clear the input field
And I type "John"
And I click the button with class "save-btn"
Then I should see the text "Profile updated"
✅ Good (declarative, business-focused):
Scenario: Update user profile
Given I am on my profile page
When I update my first name to "John"
Then my profile should be saved
And I should see a success message
Data Tables
Pass structured data to steps:
Scenario: Register new user
Given I am on the registration page
When I fill in the registration form:
| Field | Value |
| First Name | John |
| Last Name | Doe |
| Email | john@example.com |
| Password | SecurePass123! |
Then I should be registered successfully
Doc Strings
Pass multi-line text to steps:
Scenario: Submit contact form
Given I am on the contact page
When I submit a message:
"""
Hello support team,
I have a question about my recent order #12345.
Please contact me at your earliest convenience.
Best regards,
John Doe
"""
Then I should see a confirmation message
Key Principles
- Living Documentation: Features serve as executable specifications
- Collaboration: Written by developers, testers, and business stakeholders
- Ubiquitous Language: Use domain terminology consistently
- Examples over Rules: Concrete examples clarify requirements
- Automation: Scenarios are automated tests
Remember: Cucumber scenarios are specifications first, tests second. They document expected behavior in a language everyone understands.