wordpress-testing-qa

The saved excerpt is a snapshot from review. The external source remains the complete and most current version.

---
name: wordpress-testing-qa
description: "WordPress plugin and theme testing with PHPUnit integration tests, WP_Mock unit tests, PHPCS coding standards, and CI/CD workflows"
user-invocable: false
disable-model-invocation: true
progressive_disclosure:
  entry_point:
    summary: "WordPress plugin and theme testing with PHPUnit integration tests, WP_Mock unit tests, PHPCS coding standards, and CI/CD workflows"
    when_to_use: "When writing tests, implementing wordpress-testing-qa, or ensuring code quality."
    quick_start: "1. Review the core concepts below. 2. Apply patterns to your use case. 3. Follow best practices for implementation."
---
# WordPress Testing & Quality Assurance

---
progressive_disclosure:
  entry_point:
    summary: "WordPress plugin and theme testing with PHPUnit, WP_Mock, PHPCS, and CI/CD for quality assurance"
    when_to_use:
      - "Testing WordPress plugins with PHPUnit integration tests"
      - "Unit testing without loading WordPress core (WP_Mock)"
      - "Enforcing coding standards with PHPCS"
    quick_start:
      - "Set up PHPUnit with WordPress test suite"
      - "Write unit tests with WP_Mock"
      - "Configure PHPCS with WPCS ruleset"
---

## Testing Strategy

### Testing Pyramid for WordPress

**The WordPress Testing Hierarchy:**

```
       /\
      /  \     E2E Tests (Playwright)
     /    \    - Full user workflows
    /------\   - Browser automation
   /        \
  /  INTEG  \  Integration Tests (PHPUnit + WordPress)
 /    TESTS  \ - Database operations
/            \ - Hook interactions
--------------
 UNIT TESTS    Unit Tests (WP_Mock)
               - Pure logic
               - No WordPress dependency
```

**Test Distribution Guidelines:**
- **Unit Tests (60%):** Fast, isolated, no WordPress
  - Pure PHP functions
  - Class methods with clear inputs/outputs
  - Business logic without side effects
- **Integration Tests (30%):** WordPress-loaded tests
  - Database operations
  - Hook/filter interactions
  - Custom post type registration
  - Settings API functionality
- **E2E Tests (10%):** Browser automation
  - Critical user workflows
  - Admin panel interactions
  - Frontend form submissions

### When to Use PHPUnit vs WP_Mock

**Use PHPUnit (Integration Tests) when:**
- ✅ Testing database operations (`$wpdb`, post creation, meta data)
- ✅ Testing WordPress hooks (actions/filters actually firing)
- ✅ Testing template rendering and output
- ✅ Testing plugin activation/deactivation logic
- ✅ Testing with actual WordPress functions

**Use WP_Mock (Unit Tests) when:**
- ✅ Testing pure business logic
- ✅ Testing functions that call WordPress functions but logic is independent
- ✅ Need fast test execution (no database setup)
- ✅ Testing in isolation without side effects
- ✅ Mocking external API calls

### Test Coverage Goals

**Minimum Coverage Requirements:**
- **New Code:** 80% minimum coverage
- **Critical Paths:** 95% coverage (payment processing, authentication, data validation)
- **Legacy Code:** Gradual improvement, prioritize high-risk areas
- **Public APIs:** 100% coverage for all public methods

**What to Test (Priority Order):**
1. **Security Functions:** Nonce verification, sanitization, capability checks
2. **Data Operations:** Database CRUD, data validation, transformation
3. **Business Logic:** Calculations, workflows, state transitions
4. **Hook Callbacks:** Action/filter handlers
5. **Public APIs:** REST endpoints, WP-CLI commands

**What NOT to Test:**
- ❌ WordPress core functions (assume they work)
- ❌ Third-party library internals
- ❌ Simple getters/setters with no logic
- ❌ Configuration files (theme.json, block.json)

---

## PHPUnit Integration Testing

### WordPress Test Suite Setup

**Step 1: Install Dependencies**

```bash
# Install PHPUnit and WordPress polyfills
composer require --dev phpunit/phpunit "^9.6"
composer require --dev yoast/phpunit-polyfills "^2.0"

# Generate test scaffold with WP-CLI
wp scaffold plugin-tests my-plugin

# This creates:
# -