Testing PHP Applications: From Unit Tests to CI/CD

Modern PHP development is impossible without quality testing. This book is a practical guide that will take you from the basics of writing simple unit tests to building a complete continuous integration and delivery (CI/CD) pipeline. You will learn not just to write tests, but to make them useful, maintainable, and fast.

What is this book about?

The book covers all key aspects of testing PHP applications:

• Unit testing with PHPUnit: from installation and configuration to advanced techniques such as parameterized tests, data providers, and exception testing.
• Mock objects and stubs: learn to isolate the code under test from external dependencies (databases, APIs, file system). You will explore Prophecy and Mockery.
• Integration testing: testing interaction with databases (MySQL, PostgreSQL), Redis, external services, and Symfony/Laravel components.
• Test-Driven Development (TDD): master the "red-green-refactoring" cycle using real-world examples. Understand how TDD improves code architecture.
• Functional and acceptance testing: using Codeception and Behat for testing HTTP requests, forms, APIs, and UI.
• CI/CD and automation: setting up GitHub Actions, GitLab CI, or Jenkins for automatic test execution on every push. Integration with code coverage (Codecov, Scrutinizer).

Who is this book for?

• Junior and Middle PHP developers who want to stop fearing refactoring and start writing reliable code.
• Senior developers looking to systematize their knowledge and implement best testing practices within their team.
• Team Leads and Architects planning to build a quality culture and automate code review processes.
• Anyone using frameworks (Laravel, Symfony, Yii2) who wants to test their components correctly.

What will you learn after reading?

• How to write clean, isolated, and fast tests that don't break due to environment changes.
• How to choose the right testing strategy for your project (test pyramid, Occam's razor).
• How to test legacy code without a complete rewrite.
• How to use fixtures, factories, and seeds for data preparation.
• How to set up code coverage reports and achieve 80%+ metrics without fanaticism.
• How to integrate testing into the development process: code review, pre-commit hooks, automated deployment.

The book contains numerous practical examples, ready-to-use snippets, and real-world production cases. All examples are tested on PHP 8.1+ and current versions of PHPUnit 10/11, Codeception 5, Laravel 11, and Symfony 7.

Make your PHP application reliable and your development process predictable. Start testing professionally today!