**Course Title:** Mastering Yii Framework: Building Scalable Web Applications **Section Title:** Testing and Debugging in Yii **Topic:** Write unit and functional tests for a Yii application and debug using Yii Debugger.(Lab topic) **Objective:** By the end of this topic, you will be able to write unit and functional tests for a Yii application using Codeception and PHPUnit, and debug your application using the Yii Debugger. **Prerequisites:** * Familiarity with Yii framework and its ecosystem * Understanding of MVC architecture and database interactions * Basic knowledge of testing and debugging concepts **Unit Testing with Codeception:** Unit testing is an essential part of ensuring that your application works as expected. Codeception is a popular testing framework for PHP that provides a simple and efficient way to write unit tests. ### Installing Codeception To install Codeception, run the following command in your terminal: ```bash composer require --dev codeception/codeception ``` ### Writing Unit Tests Create a new test class in the `tests/unit` directory of your application. For example, let's create a test class for the `User` model: ```php // tests/unit/UserTest.php namespace tests\unit\models; use Codeception\Test\Unit; use tests\unit\fixtures\UserFixture; use app\models\User; class UserTest extends Unit { /** * @var User */ protected $user; /** * @var UserFixture */ protected $userFixture; public function _before() { $this->userFixture = new UserFixture(); $this->userFixture->load(); } public function testValidate() { $this->user = new User(); $this->user->username = 'john'; $this->user->email = 'john@example.com'; $this->assertTrue($this->user->validate()); } public function testValidateFailed() { $this->user = new User(); $this->user->username = ''; $this->user->email = ''; $this->assertFalse($this->user->validate()); } } ``` ### Running Unit Tests To run unit tests, execute the following command in your terminal: ```bash vendor/bin/codecept run unit ``` **Functional Testing with Codeception:** Functional testing is used to test the behavior of your application from a user's perspective. Codeception provides a simple way to write functional tests using the `FunctionalTester` class. ### Writing Functional Tests Create a new test class in the `tests/functional` directory of your application. For example, let's create a test class for the `SiteController`: ```php // tests/functional/SiteCest.php namespace tests\functional; use Codeception\FunctionalTester; use Codeception\Actor; class SiteCest { public function _before(FunctionalTester $I) { $I->amOnPage('/'); } public function testHomePage(FunctionalTester $I) { $I->see('Welcome to Yii!'); } public function testAboutPage(FunctionalTester $I) { $I->amOnPage('/about'); $I->see('About page'); } } ``` ### Running Functional Tests To run functional tests, execute the following command in your terminal: ```bash vendor/bin/codecept run functional ``` **Debugging with Yii Debugger:** Yii Debugger is a powerful tool for debugging your application. It provides a simple way to inspect variables, execute code, and debug your application. ### Enabling Yii Debugger To enable Yii Debugger, add the following code to your `config/web.php` file: ```php 'components' => [ 'debug' => [ 'class' => 'yii\debug\Module', 'allowedIPs' => ['127.0.0.1', '::1'], ], ], ``` ### Accessing Yii Debugger To access Yii Debugger, open your browser and navigate to `http://localhost/debug`. You will see a list of available tools, including the Debugger, Profiler, and Request. ### Using Yii Debugger To use Yii Debugger, select the Debugger tool and click on the "Variables" tab. You will see a list of available variables, including the request, response, and session. You can also use the "Code" tab to execute code and inspect variables. **Conclusion:** In this topic, we covered unit and functional testing with Codeception and debugging with Yii Debugger. We learned how to write unit tests for models and functional tests for controllers, and how to debug our application using the Yii Debugger. **Exercise:** Write a unit test for the `Post` model and a functional test for the `PostController`. Use the Yii Debugger to inspect variables and execute code. **Leave a comment:** If you have any questions or need help with the exercises, please leave a comment below. **Additional Resources:** * Codeception documentation: <https://codeception.com/docs/> * Yii Debugger documentation: <https://www.yiiframework.com/doc/guide/2.0/en/debugging>