A framework to build unit tests with OTGS products


  • Create a tests directory in your project
  • Create a phpunit subdirectory in tests1
  • Copy samples/phpunit.xml file in the root of your project2
    • Change test-suite-name into something appropriated
    • Most likely, you won't need to change anything else in that file
  • Copy samples/bootstrap.php into tests/phpunit
    • Read the comments in this file and make the appropriated changes
  • Run composer require --dev otgs/unit-tests-framework3
  • Create another tests subdirectory in tests/phpunit
    • Write your tests there
    • Unless you have customized the phpunit.xml file, you don't need to name the test files and classes in any particular way
  • Run phpunit from your project's root to start your tests4

How to use the OTGS_TestCase class

In order to take the most of this library, all your tests classes should extext OTGS_TestCase.

Once you do that, this will happen:

  1. \OTGS_TestCase::setupBeforeClass:
  • $_GET and $_POST are set to an empty array
  • An instance of FactoryMuffin is provided: you can refer to it as self::$fm (see "Resources and dependencies" for more details)
  1. \OTGS_TestCase::setUp
  • FunctionMocker is initialized (see "Resources and dependencies" for more details)
  • WP_Mock is initialized (see "Resources and dependencies" for more details)
  1. \OTGS_TestCase::tearDown
  • WP_Mock is destroyed
  • FunctionMocker is destroyed
  • Mockery is destroyed (just in case it has been used)
  1. \OTGS_TestCase::tearDownAfterClass
  • Deletes all models created with FactoryMuffin

Mock WP Core functions

This class also provide an helper method to quickly mock the functions defined by WordPress by using the \OTGS_TestCase::get_mocked_wp_core_functions which returns an instance of OTGS_Mocked_WP_Core_Functions.

OTGS_Mocked_WP_Core_Functions organize mocks in methods named using the same name of the file where the function is defined in WordPress codebase.

For instance, to mock of all functions defined in post.php like get_post, in your test you should simply call $this->get_mocked_wp_core_functions()->post().

To mock add_query_arg yo call $this->get_mocked_wp_core_functions()->functions() because add_query_arg is defined in functions.php.

OTGS_Mocked_WP_Core_Functions tries to handle dependencies.

So, if you call $this->get_mocked_wp_core_functions()->post() to mock wp_insert_post, you automatically call $this->get_mocked_wp_core_functions()->post(), so to get all the meta related functions mocked as well.
Finally, there is a "mock all" method you could use (though is discouraged) with $this->mock_all_core_functions().

Stub WP common classes

\OTGS_TestCase provides a helpful way to quickly get a stub of some of the most commonly used classes in WordPress.

By calling $this->stubs->wpdb() you will get a stub you can pass as a dependency of the classes you are testing. If you need to control the behavior of this stub, you just use the standard PHPUnit mock helpers.

E.g. 1:

$wpdb = $this->stubs->wpdb();  
$wpdb->method( 'get_var' )->willReturn( 1 );

E.g. 2:

$results = array(
	array( 'translation_id' => 1, 'element_id' => 1, 'language_code' => 'en', 'source_language_code' => null, 'trid' => 1, 'element_type' => 'post_page' ),
	array( 'translation_id' => 2, 'element_id' => 2, 'language_code' => 'fr', 'source_language_code' => 'en', 'trid' => 1, 'element_type' => 'post_page' ),
$wpdb = $this->this->wpdb();
$wpdb->expects( $this->exactly( 2 ) )->method( 'get_results' )->willReturn( $results );

Other stubs you can get:

  • WP_Widget with $this->stubs->WP_Widget()
  • WP_Theme with $this->stubs->WP_Theme()
  • WP_Filesystem_Direct with $this->stubs->WP_Filesystem_Direct()
  • WP_Query with $this->stubs->WP_Query()

It is important to know that, if you only need the class to be defined (e.g. hard-dependency, or sub-classing), you don't need to assig the stub to a variable: just call the method.

A good example is with WordPress' widgets, where you may have your own widget which is supposed to extend WP_Widget.

In this case, unless you want to mock some of the WP_Widget methods, you simply call $this->stubs->WP_Widget(), then write your tests.
The class which extends WP_Widget will find a definition of this class, with all the methods (doing nothing).

Resources and dependencies

Below are some resources on writing unit tests which lead to the creation of this library and links to the libraries included here:


  1. it is recommended to keep your PHPUnit tests into a subfolder, because there are good changes you want to add other kind of tests (e.g. QUnit, PHPSpec, etc.)

  2. in case, for whatever reason, you can't do that, copy this file in tests/phpunit or wherever you find it more convenient

  3. In some cases, you may want to use composer require --dev otgs/unit-tests-framework:dev-develop. When you do that, you may also need to run this command first composer config minimum-stability dev

  4. If you've placed the phpunit.xml you need to either move to that directory first, or tell phpunit where the file is with phpunit --configuration path/to/phpunit.xml