Despite the wide popularity of TDD, few PHP developers ever write automatic tests for their applications. The Codeception framework was developed to make the testing actually fun. It allows writing unit, functional, integration, and acceptance tests in one style.

It could be called a BDD framework. All Codeception tests are written in a descriptive manner. Just by looking in the test body you can get a clear understanding of what is being tested and how it is performed. Even complex tests with many assertions are written in a simple PHP DSL.

We took a look into the Codeception structure. Most of the things you need were already generated by the `bootstrap` command. After you have reviewed the basic concepts and configurations, you can start writing your first scenarios.

If you have written a module that may be useful to others, share it.

Fork the Codeception repository, put the module into the `src/Codeception/Module` directory, and send a pull request. Many thanks if you do so.

Writing acceptance tests with Codeception and PhpBrowser is a good start. You can easily test your Joomla, Drupal, Wordpress sites, as well as those made with frameworks. Writing acceptance tests is like describing a tester's actions in PHP. They are quite readable and very easy to write. Don't forget to repopulate the database on each test run.

Functional tests are great if you are using powerful frameworks. By using functional tests you can access and manipulate their internal state.

This makes your tests shorter and faster. In other cases, if you don't use frameworks, there is no practical reason to write functional tests.

If you are using a framework other than the ones listed here, create a module for it and share it with community.

PHPUnit tests is a first-class citizen in test suites. Whenever you need to write and execute unit tests, you don't need to install PHPUnit manually, but use a Codeception to execute them. Some nice features are added to common unit tests by integrating Codeception modules. For most of unit and integration testing PHPUnit tests are just enough. They are fast and easy to maintain. But when you need some advanced features like mocking, use the special Cest format, described in next chapters.

You are free to decide the testing framework you will use for unit tests. Codeception and PHPUnit run the same engine.

Codeception provides you with a cool DSL to simplify your unit tests. You are writing the scenario definitions, not the actual executed code. Behind the scenes all the dirty work is done by Codeception. You write only the testing logic.

Codeception has it's powers and it's limits. We believe Codeception's limitations keep your tests clean and narrative. Codeception makes writing bad code for tests more difficult. Codeception has simple but powerful tools to create stubs and mocks. Different modules can be attached to unit tests which, just for an example, will simplify database interactions.

Codeception is not abandoning the developer when dealing with data. Tools for database population and cleanups are bundled within the Db module.

To manipulate sample data in a test, use fixtures that can be defined within the bootstrap file.