Acceptance Criteria Skill

Transform requirements into testable acceptance criteria.

Core Concept

Acceptance criteria are the contract between product and delivery:

• Product: "Here's what success looks like"
• QE: "Here's how we verify it"
• Engineering: "Here's what we must deliver"

Given/When/Then Format

Given [precondition/context]
When [action/event]
Then [expected outcome]

Why this format?

• Forces specificity
• Testable by definition
• Clear success criteria
• Language-agnostic

Process

1. Read Requirements

Understand:

• User stories
• Design documents
• Business rules
• Constraints

2. Identify Scenarios

For each requirement, consider:

• Happy path: Normal, expected flow
• Error conditions: Invalid inputs, failures
• Edge cases: Boundaries, empty states
• Non-functional: Performance, security, usability

3. Write Criteria

Format each scenario:

Given [specific context]
When [specific action]
Then [specific, measurable outcome]

4. Validate

Check each criterion:

• Specific (not vague)
• Testable (can verify)
• Measurable (clear pass/fail)
• Independent (standalone)
• Complete (covers scenario)

5. Organize by Priority

• P0: Must have (blocker if missing)
• P1: Should have (important)
• P2: Nice to have (enhancement)

Example: Login Feature

### US1: User Authentication

**Happy Path (P0)**:
AC1: Given valid credentials, When user submits login, Then user redirected to dashboard
AC2: Given successful login, When checking session, Then session valid for 30 minutes

**Error Handling (P0)**:
AC3: Given invalid password, When user submits login, Then error message "Invalid credentials"
AC4: Given account locked, When user submits login, Then error message "Account locked"
AC5: Given 3 failed attempts, When user tries again, Then account locked for 15 minutes

**Edge Cases (P1)**:
AC6: Given empty email field, When user submits, Then error "Email required"
AC7: Given malformed email, When user submits, Then error "Invalid email format"
AC8: Given concurrent logins, When second login occurs, Then first session invalidated

**Non-Functional (P1)**:
AC9: Given 1000 concurrent logins, When system under load, Then response time < 2 seconds
AC10: Given login attempt, When credentials checked, Then password encrypted in transit

Common Patterns

Data Creation:

Given user on create form
When user enters valid data and submits
Then new record saved and confirmation shown

Data Validation:

Given user on form with required fields
When user submits without filling required field
Then error message shown and form not submitted

Authorization:

Given user without admin role
When user attempts admin action
Then access denied message shown

API Response:

Given valid API request
When endpoint called
Then 200 status and expected JSON schema returned

Integration with QE

Acceptance criteria feed directly into test scenarios:

# Product defines AC
wicked-garden-product acceptance phases/design/

# Generate test scenarios from AC
wicked-garden-qe plan

Flow:

1. Product: Write acceptance criteria
2. QE: Review and generate test scenarios
3. Engineering: Implement to meet criteria
4. QE: Verify against criteria

Quality Checklist

Good acceptance criteria:

• Use Given/When/Then format
• Specific and unambiguous
• Testable with clear pass/fail
• Cover happy path, errors, edges
• Include non-functional requirements
• Prioritized by criticality
• Reviewed by QE for testability

Output Format

## Acceptance Criteria

### User Story: {Story Title}

**Happy Path**:
- AC1: Given {context}, When {action}, Then {outcome} [P0]

**Error Conditions**:
- AC2: Given {error}, When {action}, Then {handling} [P0]

**Edge Cases**:
- AC3: Given {edge}, When {action}, Then {behavior} [P1]

**Non-Functional**:
- AC4: Given {load}, When {action}, Then {performance} [P1]

**Test Data Requirements**:
- {Data needed for testing}

**QE Handoff Notes**:
- {Special testing considerations}

Progressive Disclosure

• SKILL.md (this file): Quick reference
• refs/ac-examples.md: More examples by domain
• refs/ac-anti-patterns.md: Common mistakes to avoid