How to create and configure a custom module in Codeception

Codeception is a testing framework with many functionalities. These functionalities are bundled in so-called modules. Some modules are used in most tests, like the Asserts module. Other provide more specific functions, like the Laravel5 module or the Filesystem module.

Why would you?

For a recent project, I had to import existing news items into a new website without database access. So I decided to use Codeception's acceptance testing tool to automate the process.

During the process, some modules had to be extended to allow for my need. For example, the database module has a method for retrieving a record from the database. What I needed was a method to retrieve all records from the database, which is a small extension.

Create a module

A very basic module for Codeception looks something like this:

/tests/_support/Helper/MyModule.php:

<?php

namespace Helper;

class MyModule extends \Codeception\Module
{

    /** @var array */
    protected $config = [
        'foo' => true,
    ];

    /**
     * HOOK:
     * triggered after module is created and configuration is loaded
     */
    public function _initialize()
    {
        // ...
    }
}

A module has multiple hooks that allow you to act on certain key events in the testing cycle:

  • _beforeSuite($settings = [])
  • _afterSuite()
  • _beforeStep(Step $step)
  • _afterStep(Step $step)
  • _before(TestInterface $test)
  • _after(TestInterface $test)
  • _failed(TestInterface $test, $fail)
  • _cleanup()

Read more about hooks in the docs.

Extending modules

Of course, it is also possible to extend on existing modules, which is what I did myself. Instead of extending \Codeception\Module you can extend \Codeception\Module\Db or any other module. Then it is possible to alter methods or add your own.

/tests/_support/Helper/ExtendedDb.php:

<?php

namespace Helper;

class ExtendedDb extends \Codeception\Module\Db
{
    public function grabRowsFromDatabase($table, $criteria = [])
    {
        // ...
    }
}

Configuring custom modules

Modules can be enabled in the global configuration (using codeception.yml) or on a specific suite (using, for example, acceptance.suite.yml).

My acceptance.suite.yml configuration currently looks something like this:

class_name: AcceptanceTester
modules:
    enabled:
        - \Helper\Acceptance
        - \Helper\ExtendedDb
        - Asserts
    config:
        \Helper\ExtendedDb:
            dsn: "mysql:host=%DB_HOST%:%DB_PORT%;dbname=%DB_DATABASE%"
            user: "%DB_USERNAME%"
            password: "%DB_PASSWORD%"

As you can see this configuration is the same as for the default Db module. Any of the configuration variables is available within the module on the $this->config class variable.

Read more about modules and helpers in the official docs.

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