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name: woocommerce-backend-dev description: Add or modify WooCommerce backend PHP code following project conventions. Use when creating new classes, methods, hooks, or modifying existing backend code. MUST be invoked before writing any PHP unit tests.

WooCommerce Backend Development

This skill provides guidance for developing WooCommerce backend PHP code according to project standards and conventions.

When to Use This Skill

ALWAYS invoke this skill before:

• Writing new PHP unit tests (*Test.php files)
• Creating new PHP classes
• Modifying existing backend PHP code
• Adding hooks or filters

Instructions

Follow WooCommerce project conventions when adding or modifying backend PHP code:

1. Creating new code structures: See file-entities.md for conventions on creating classes and organizing files (but for new unit test files see unit-tests.md).
2. Naming conventions: See code-entities.md for naming methods, variables, and parameters
3. Coding style: See coding-conventions.md for general coding standards and best practices
4. Type annotations: See type-annotations.md for PHPStan-aware PHPDoc annotations
5. Working with hooks: See hooks.md for hook callback conventions and documentation
6. Dependency injection: See dependency-injection.md for DI container usage
7. Data integrity: See data-integrity.md for ensuring data integrity when performing CRUD operations
8. Writing tests: See unit-tests.md for unit testing conventions

Key Principles

• Always follow WordPress Coding Standards
• Use class methods instead of standalone functions
• Place new internal classes in src/Internal/ by default
• Use PSR-4 autoloading with Automattic\WooCommerce namespace
• Write comprehensive unit tests for new functionality
• Run linting and tests before committing changes

Version Information

To determine the next WooCommerce version number for @since annotations:

• Read the $version property in includes/class-woocommerce.php on the trunk branch
• Remove the -dev suffix if present
• Example: If trunk shows 10.4.0-dev, use @since 10.4.0
• Note: When reviewing PRs against trunk, the version in trunk is correct even if it seems "future" relative to released versions