Functional tests are written in the same manner as [Acceptance Tests](http://codeception.com/docs/04-AcceptanceTests) with `PhpBrowser` module enabled. All framework modules and `PhpBrowser` module share the same methods and the same engine.

In both examples you should not be worried about the data persistance between tests.

However Cest format is better at separating concerns. Test code does not interefere with support code, provided by `UnitTester` object. All additional actions you may need in your unit/intergation tests you can implement in `Helper\Unit` class. This is the recommended approach, and allows keeping tests verbose and clean.

$I->submitForm('#loginForm' [

Same as above, StepObject can be instanticated automatically by Dependency Injection Container, when used inside Cest format:

For acceptance and functional testing we will need not only to have common actions to be reused accross different tests, we should have buttons, links, and form fields to be reused as well. For those cases we need to implement

The dependency injection container can construct any object that require any known class type. For instance, `Page\Login` required `AcceptanceTester`, and so it was injected into `Page\Login` constructor, and PageObject was created and passed into method arguments. You should specify explicitly the types of requried objects for Codeception to know what objects should be created for a test. Dependency Injection will be described in the next chapter.

In `_before` and `_after` methods you can use common setups and teardowns for the tests in the class. This actually makes Cest tests more flexible then Cepts, which rely only on similar methods in Helper classes.

In order to make auto-wiring work, you will need to implement `_inject()` method with the list of desired arguments. It is important to speicfy the type of arguments, so Codeception can guess which objects are expected to be received. The `_inject()` will be invoked just once right after creation of the TestCase object (either Cest or Test). Dependency Injection will also work in a similar manner for Helper and Actor classes.

Codeception comes with bundled extensions located in `ext` directory. For instance, you can enable Logger extension to log test exection with Monolog

We are using XmlUtils class which allows us to build XML structures in a clean manner. The `toXml` method may accept a string or array and returns \DOMDocument instance. If your XML contains attributes and so can't be represented as a PHP array you can create XML using the [XmlBulder](http://codeception.com/docs/reference/XmlBuilder) class. We will take a look at it a bit more in next section.

We should not rely on console output when running our tests. In case of `parallelExec` task, some text can be missed. We recommmend to save results as JUnit XML, which can be merged and plugged into Continuous Integration server.