Implement automated tests to ensure plugin reliability. Unit tests verify individual functions work correctly. Integration tests check how components work together. Use PHPUnit for testing WordPress plugins. Create test fixtures and mocks for dependencies. Test edge cases and error conditions. Continuous testing catches regressions early. Maintain high code coverage for critical functions. Automated tests save time during development and updates. They provide confidence when making changes. Well-tested plugins are more reliable and maintainable. Testing is investment in plugin quality.