Reusing Test Code

Codeception uses modularity to create a comfortable testing environment for every test suite you write. Modules allow you to choose the actions and assertions that can be performed in tests.

What are Actors

All actions and assertions that can be performed by the Actor object in a class are defined in modules. It might look like Codeception limits you in testing, but that’s not true. You can extend the testing suite with your own actions and assertions, by writing them into a custom module, called a Helper. We will get back to this later in this chapter, but for now let’s look at the following test:

<?php
$I->amOnPage('/');
$I->see('Hello');
$I->seeInDatabase('users', ['id' => 1]);
$I->seeFileFound('running.lock');

It can operate with different entities: the web page can be loaded with the PhpBrowser module, the database assertion uses the Db module, and the file state can be checked with the Filesystem module.

Modules are attached to Actor classes in the suite config. For example, in tests/acceptance.suite.yml we should see:

actor: AcceptanceTester
modules:
    enabled:
        - PhpBrowser:
            url: http://localhost
        - Db
        - Filesystem

The AcceptanceTester class has its methods defined in modules. Let’s see what’s inside the AcceptanceTester class, which is located inside the tests/_support directory:

<?php
/**
 * Inherited Methods
 * @method void wantToTest($text)
 * @method void wantTo($text)
 * @method void execute($callable)
 * @method void expectTo($prediction)
 * @method void expect($prediction)
 * @method void amGoingTo($argumentation)
 * @method void am($role)
 * @method void lookForwardTo($achieveValue)
 * @method void comment($description)
 * @method void haveFriend($name, $actorClass = null)
 *
 * @SuppressWarnings(PHPMD)
*/
class AcceptanceTester extends \Codeception\Actor
{
    use _generated\AcceptanceTesterActions;

   /**
    * Define custom actions here
    */
}

The most important part is the _generated\AcceptanceTesterActions trait, which is used as a proxy for enabled modules. It knows which module executes which action and passes parameters into it. This trait was created by running codecept build and is regenerated each time module or configuration changes.

Use actor classes to set common actions which can be used accross a suite.

PageObjects

For acceptance and functional testing, we will not only need to have common actions being reused across different tests, we should have buttons, links and form fields being reused as well. For those cases we need to implement the PageObject pattern, which is widely used by test automation engineers. The PageObject pattern represents a web page as a class and the DOM elements on that page as its properties, and some basic interactions as its methods. PageObjects are very important when you are developing a flexible architecture of your acceptance or functional tests. Do not hard-code complex CSS or XPath locators in your tests but rather move them into PageObject classes.

Codeception can generate a PageObject class for you with command:

php vendor/bin/codecept generate:pageobject acceptance Login

It is recommended to use page objects for acceptance testing only

This will create a Login class in tests/_support/Page/Acceptance. The basic PageObject is nothing more than an empty class with a few stubs.

It is expected that you will populate it with the UI locators of a page it represents. Locators can be added as public properties:

<?php
namespace Page\Acceptance;

class Login
{
    public static $URL = '/login';

    public $usernameField = '#mainForm #username';
    public $passwordField = '#mainForm input[name=password]';
    public $loginButton = '#mainForm input[type=submit]';

    // ...
}

But let’s move further. The PageObject concept specifies that the methods for the page interaction should also be stored in a PageObject class.

Let’s define a login method in this class:

<?php
namespace Page\Acceptance;

class Login
{
    public static $URL = '/login';

    public $usernameField = '#mainForm #username';
    public $passwordField = '#mainForm input[name=password]';
    public $loginButton = '#mainForm input[type=submit]';

    /**
     * @var AcceptanceTester
     */
    protected $tester;

    // we inject AcceptanceTester into our class
    public function __construct(\AcceptanceTester $I)
    {
        $this->tester = $I;
    }

    public function login($name, $password)
    {
        $I = $this->tester;

        $I->amOnPage(self::$URL);
        $I->fillField($this->usernameField, $name);
        $I->fillField($this->passwordField, $password);
        $I->click($this->loginButton);
    }
}

If you specify which object you need for a test, Codeception will try to create it using the dependency injection container. In the case of a PageObject you should declare a class as a parameter for a test method:

<?php
class UserCest
{
    function showUserProfile(AcceptanceTester $I, \Page\Acceptance\Login $loginPage)
    {
        $loginPage->login('bill evans', 'debby');
        $I->amOnPage('/profile');
        $I->see('Bill Evans Profile', 'h1');
    }
}

The dependency injection container can construct any object that requires 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 explicitly specify the types of required objects for Codeception to know what objects should be created for a test. Dependency Injection will be described in the next chapter.

StepObjects

StepObjects are great if you need some common functionality for a group of tests. Let’s say you are going to test an admin area of a site. You probably won’t need the same actions from the admin area while testing the front end, so it’s a good idea to move these admin-specific tests into their own class. We call such a classes StepObjects.

Lets create an Admin StepObject with the generator:

php vendor/bin/codecept generate:stepobject acceptance Admin

You can supply optional action names. Enter one at a time, followed by a newline. End with an empty line to continue to StepObject creation.

php vendor/bin/codecept generate:stepobject acceptance Admin
Add action to StepObject class (ENTER to exit): loginAsAdmin
Add action to StepObject class (ENTER to exit):
StepObject was created in /tests/acceptance/_support/Step/Acceptance/Admin.php

This will generate a class in /tests/_support/Step/Acceptance/Admin.php similar to this:

<?php
namespace Step\Acceptance;

class Admin extends \AcceptanceTester
{
    public function loginAsAdmin()
    {
        $I = $this;
    }
}

As you see, this class is very simple. It extends the AcceptanceTester class, meaning it can access all the methods and properties of AcceptanceTester.

The loginAsAdmin method may be implemented like this:

<?php
namespace Step\Acceptance;

class Admin extends \AcceptanceTester
{
    public function loginAsAdmin()
    {
        $I = $this;
        $I->amOnPage('/admin');
        $I->fillField('username', 'admin');
        $I->fillField('password', '123456');
        $I->click('Login');
    }
}

StepObject can be instantiated automatically when used inside the Cest format:

<?php
class UserCest
{
    function showUserProfile(\Step\Acceptance\Admin $I)
    {
        $I->loginAsAdmin();
        $I->amOnPage('/admin/profile');
        $I->see('Admin Profile', 'h1');
    }
}

If you have a complex interaction scenario, you may use several step objects in one test. If you feel like adding too many actions into your Actor class (which is AcceptanceTester in this case) consider moving some of them into separate StepObjects.

Use StepObjects when you have multiple areas of applications or multiple roles.

Conclusion

There are lots of ways to create reusable and readable tests. Group common actions together and move them to an Actor class or StepObjects. Move CSS and XPath locators into PageObjects. Write your custom actions and assertions in Helpers. Scenario-driven tests should not contain anything more complex than $I->doSomething commands. Following this approach will allow you to keep your tests clean, readable, stable and make them easy to maintain.

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