Yii2 Advanced Application uses Codeception as its primary test framework. There are already some sample tests prepared in tests directory of frontend, backend, and common. In order for the following procedure to work, it is assumed that the application has been initialized using the dev environment. In the case where tests need to be executed in a Production environment, yii_test and yii_test.bat must be manually copied from the environments/dev folder into the project root directory.

Tests require an additional database, which will be cleaned up between tests. This database will be used to hold data that matches the data in your live database. Its purpose is to run those tests that store data without affecting your own data. Create database in your database server, using a similar setup to the live database, so that the tests are run in an environment that is as close to your live environment as possible.

  1. Your live database connection string is probably in common/config/main-local.php. It is something like 'dsn' => 'mysql:host=localhost;dbname=yii2advanced'. Copy it to common/config/test-local.php and change the dbname so it is obvious that it is the test database: 'dsn' => 'mysql:host=localhost;dbname=yii2advanced_test'.
  2. Create an empty database. In this example it would be yii2advanced_test in MySql (according to config in common/config/test-local.php).
  3. Execute: ./yii_test migrate.
  4. Build the test suite: ./vendor/bin/codecept build

Then all sample tests can be started by running:

vendor/bin/codecept run

You will see output similar to this:

It is recommended to keep your tests up to date. If a class, or functionality is deleted, corresponding tests should be deleted as well. You should run tests regularly, or better to set up Continuous Integration server for them.

Please refer to Yii2 Framework Case Study to learn how to configure Codeception for your application.


Tests for common classes are located in common/tests. In this template there are only unit tests. Execute them by running:

vendor/bin/codecept run -- -c common

-c option allows to set path to codeception.yml config.

Tests in unit test suite (located in common/tests/unit) can use Yii framework features: Yii::$app, Active Record, fixtures, etc. This is done because Yii2 module is enabled in unit tests config: common/tests/unit.suite.yml. You can disable it to run tests in complete isolation.


Frontend tests contain unit tests, functional tests, and acceptance tests. Execute them by running:

vendor/bin/codecept run -- -c frontend

Description of test suites:

  • unit ⇒ classes related to frontend application only.
  • functional ⇒ application internal requests/responses (without a web server).
  • acceptance ⇒ web application, user interface and javascript interactions in real browser.

By default acceptance tests are disabled, to run them use:

Running Acceptance Tests

The acceptance tests use geckodriver for firefox by default, so make sure geckodriver is in the PATH.

To execute acceptance tests do the following:

  1. Rename frontend/tests/acceptance.suite.yml.example to frontend/tests/acceptance.suite.yml to enable suite configuration

  2. Replace codeception/base package in composer.json with codeception/codeception to install full featured version of Codeception

  3. Update dependencies with Composer

    composer update

  4. Auto-generate new support classes for acceptance tests:

    vendor/bin/codecept build -- -c frontend

  5. Download Selenium Server and launch it:

    java -jar ~/selenium-server-standalone-x.xx.x.jar > There are currently issues with geckodriver's > interactions with selenium that require you to enable the protocol translating in Selenium. > java -jar ~/selenium-server-standalone-x.xx.x.jar -enablePassThrough false

  6. Start web server:

    php -S -t frontend/web

  7. Now you can run all available tests

    vendor/bin/codecept run acceptance -- -c frontend


Backend application contain unit and functional test suites. Execute them by running:

vendor/bin/codecept run -- -c backend