Codeception uses PHPUnit as a backend for running its tests. Thus, any PHPUnit test can be added to Codeception test suite
and then executed. If you ever wrote a PHPUnit test then do it just as you did before.
Codeception adds some nice helpers to simplify common tasks.
The basics of unit tests are skipped here, instead you will get a basic knowledge of what features Codeception adds
to unit tests.
To say it again: you don’t need to install PHPUnit to run its tests. Codeception can run them too.
Codeception has nice generators to simplify test creation. You can start by generating a classical PHPUnit test
\PHPUnit_Framework_TestCase class. This can be done by this command:
Codeception has its own addon features to extend standard unit tests, so let’s try them.
We need different command to create Codeception-powered unit tests:
Both commands will create a new
ExampleTest file located in the
As always, you can run the newly created test with this command:
or simply run the whole set of unit tests with this:
A test created by the
generate:test command will look like this:
This class has predefined
_after methods to start with.
You can use them to create a tested object before each test, and destroy it again afterwards.
As you see, unlike in PHPUnit, the
tearDown methods are replaced with their aliases:
tearDown are implemented by the parent class
and set the UnitTester class up to have all the cool actions from Cept-files to be run as a part of your unit tests.
Just like in the acceptance and functional tests, you can choose the proper modules
UnitTester class in the
unit.suite.yml configuration file:
Classical Unit Testing
Unit tests in Codeception are written in absolutely the same way as it is done in PHPUnit:
As in scenario-driven functional or acceptance tests you can access Actor class methods.
If you write integration tests, it may be useful to include
Db module for database testing.
To access UnitTester methods you can use the
UnitTester property in a test.
Let’s see how you can do some database testing:
To enable the database functionality in the unit tests, make sure the
Db module is included in the enabled module list
in the unit.suite.yml configuration file.
The database will be cleaned and populated after each test, the same way it happens for acceptance and functional tests.
If it’s not your required behavior, change the settings of the
Db module for the current suite.
Interacting with the Framework
You should probably not access your database directly if your project already uses ORM for database interactions.
Why not use ORM directly inside your tests? Let’s try to write a test using Laravel’s ORM Eloquent,
for this we need to configure the Laravel5 module. We won’t need its web interaction methods like
so let’s enable only the ORM part of it:
We included the Laravel5 module the same way we did for functional testing.
Let’s see how we can use it for integration tests:
A very similar approach can be used for all frameworks that have ORM implementing ActiveRecord pattern.
They are Yii2 and Phalcon, and they have the methods
dontSeeRecord which work in the same way.
They also should be included by specifying
part: ORM in order to not use the functional testing actions.
If you are using Symfony with Doctrine, you don’t need to enable Symfony itself but just Doctrine2:
In this case you can use the methods from the Doctrine2 module, while Doctrine itself uses the Symfony module
to establish connections to the database. In this case a test might look like:
In both examples you should not be worried about the data persistence between tests.
The Doctrine2 and Laravel5 modules will clean up the created data at the end of a test.
This is done by wrapping a test in a transaction and rolling it back afterwards.
Codeception allows you to access the properties and methods of all modules defined for this suite.
Unlike using the UnitTester class for this purpose, using a module directly grants you access
to all public properties of that module.
We have already demonstrated this in a previous example where we accessed the Entity Manager from a Doctrine2 module:
If you use the
Symfony module, here is how you can access the Symfony container:
The same can be done for all public properties of an enabled module. Accessible properties are listed in the module reference.
BDD Specification Testing
When writing tests you should prepare them for constant changes in your application.
Tests should be easy to read and maintain. If a specification of your application is changed,
your tests should be updated as well. If you don’t have a convention inside your team for documenting tests,
you will have issues figuring out what tests will be affected by the introduction of a new feature.
That’s why it’s pretty important not just to cover your application with unit tests, but make unit tests self-explanatory.
We do this for scenario-driven acceptance and functional tests, and we should do this for unit and integration tests as well.
For this case we have a stand-alone project Specify
(which is included in the phar package) for writing specifications inside unit tests:
specify codeblocks, you can describe any piece of a test.
This makes tests much cleaner and comprehensible for everyone in your team.
specify blocks is isolated. In the example above, any changes to
(as with any other object property),
will not be reflected in other code blocks. Specify uses deep and shallow cloning strategies to save objects
between isolated scopes. The downsides of this approach is increased memory consumption (on deep cloning)
or incomplete isolation when shallow cloning is used. Please make sure you understand
how Specify works and how to configure it before using it in your tests.
Also, you may add Codeception\Verify for BDD-style assertions.
This tiny library adds more readable assertions, which is quite nice, if you are always confused
about which argument in
assert calls is expected and which one is actual:
As an alternative to testcases extended from
PHPUnit_Framework_TestCase, you can use the Codeception-specific Cest format.
It does not need to be extended from any other class. All public methods of this class are tests.
The example above can be rewritten in scenario-driven manner like this:
For unit testing you may include the
Asserts module, that adds regular assertions to UnitTester
which you may access from the
Learn more about Cest format.
It may look like the Cest format is too simple for writing tests. It doesn't provide assertion methods,
methods to create mocks and stubs or even accessing the module with `getModule`, as we did in example above.
However, the Cest format is better at separating concerns. Test code does not interfere with support code,
provided by the `UnitTester` object. All additional actions you may need in your unit/integration tests
you can implement in the `Helper\Unit` class.
To check your code for exceptions you can use the
expectException method from
Unlike the similar method from PHPUnit, this method asserts that an exception was thrown inside a test.
For this code, executing an exception is wrapped inside a closure:
Codeception provides a tiny wrapper over the PHPUnit mocking framework to create stubs easily.
\Codeception\Util\Stub to start creating dummy objects.
In this example we instantiate an object without calling a constructor and replace the
to return the value john:
Stubs are created with PHPUnit’s mocking framework. Alternatively, you can use
Mockery (with Mockery module),
AspectMock or others.
Full reference on the Stub utility class can be found here.
PHPUnit tests are first-class citizens in test suites. Whenever you need to write and execute unit tests,
you don’t need to install PHPUnit seperately, but use Codeception directly to execute them.
Some nice features can be added to common unit tests by integrating Codeception modules.
For most unit and integration testing, PHPUnit tests are enough. They are fast, and easy to maintain.