Overview

Learn to write clear, maintainable BDD scenarios that effectively capture business requirements and drive implementation.

Writing Good Scenarios

A good scenario should be:

• Specific: Test one behavior
• Declarative: Describe what, not how
• Business-focused: Use domain language
• Independent: No dependencies on other scenarios

# Good scenario - specific and declarative
Scenario: Customer receives loyalty discount
  Given a customer with Gold membership status
  And a cart total of $100
  When the customer proceeds to checkout
  Then a 10% loyalty discount should be applied
  And the final total should be $90

# Bad scenario - too implementation-focused
Scenario: Apply discount
  Given I click the membership dropdown
  And I select "Gold" from the list
  When I click the checkout button
  Then the JavaScript calculates 10% off

Acceptance Criteria Format

Feature: Order Refunds

  # Rule-based acceptance criteria
  Rule: Full refunds are available within 30 days

    Scenario: Refund requested within return window
      Given an order placed 15 days ago
      When the customer requests a refund
      Then a full refund should be processed

    Scenario: Refund requested after return window
      Given an order placed 45 days ago
      When the customer requests a refund
      Then the refund should be denied
      And the customer should see "Return window expired"

Edge Case Scenarios

Feature: User Registration

  Scenario: Successful registration
    Given I am on the registration page
    When I submit valid registration details
    Then my account should be created

  # Edge cases
  Scenario: Registration with existing email
    Given a user exists with email "existing@example.com"
    When I try to register with email "existing@example.com"
    Then I should see "Email already registered"

  Scenario: Registration with invalid email format
    When I try to register with email "not-an-email"
    Then I should see "Please enter a valid email"

  Scenario: Registration with empty required fields
    When I submit the registration form with empty fields
    Then I should see validation errors for required fields

Scenario Tags and Organization

@authentication @critical
Feature: User Login

  @smoke
  Scenario: Basic login flow
    # ...

  @security
  Scenario: Account lockout after failed attempts
    # ...

  @wip
  Scenario: Two-factor authentication
    # Work in progress

When to Use This Skill

Use bdd-scenarios when you need to:

• Define acceptance criteria for user stories
• Document expected system behavior
• Create comprehensive test coverage
• Identify edge cases early in development
• Communicate requirements clearly

Best Practices

• Start with the happy path scenario
• Add edge cases systematically
• Use tags for organization and filtering
• Keep scenarios at 3-7 steps
• Write scenarios before implementation
• Review scenarios with stakeholders

Common Pitfalls

• Writing scenarios after implementation
• Including too many steps per scenario
• Using vague or ambiguous language
• Forgetting negative test cases
• Not organizing with tags effectively