PHPUnit Mock Objects and Static Methods - php

Question

I am looking for the best way to go about testing the following static method (specifically using a Doctrine Model):
class Model_User extends Doctrine_Record
{
public static function create($userData)
{
$newUser = new self();
$newUser->fromArray($userData);
$newUser->save();
}
}
Ideally, I would use a mock object to ensure that fromArray (with the supplied user data) and save were called, but that's not possible as the method is static.
Any suggestions?

Answer 1

Sebastian Bergmann, the author of PHPUnit, recently had a blog post about Stubbing and Mocking Static Methods. With PHPUnit 3.5 and PHP 5.3 as well as consistent use of late static binding, you can do
$class::staticExpects($this->any())
->method('helper')
->will($this->returnValue('bar'));
Update: staticExpects is deprecated as of PHPUnit 3.8 and will be removed completely with later versions.

Answer 2

There is now the AspectMock library to help with this:
https://github.com/Codeception/AspectMock
$this->assertEquals('users', UserModel::tableName());
$userModel = test::double('UserModel', ['tableName' => 'my_users']);
$this->assertEquals('my_users', UserModel::tableName());
$userModel->verifyInvoked('tableName');

Answer 3

I would make a new class in the unit test namespace that extends the Model_User and test that. Here's an example:
Original class:
class Model_User extends Doctrine_Record
{
public static function create($userData)
{
$newUser = new self();
$newUser->fromArray($userData);
$newUser->save();
}
}
Mock Class to call in unit test(s):
use \Model_User
class Mock_Model_User extends Model_User
{
/** \PHPUnit\Framework\TestCase */
public static $test;
// This class inherits all the original classes functions.
// However, you can override the methods and use the $test property
// to perform some assertions.
}
In your unit test:
use Module_User;
use PHPUnit\Framework\TestCase;
class Model_UserTest extends TestCase
{
function testCanInitialize()
{
$userDataFixture = []; // Made an assumption user data would be an array.
$sut = new Mock_Model_User::create($userDataFixture); // calls the parent ::create method, so the real thing.
$sut::test = $this; // This is just here to show possibilities.
$this->assertInstanceOf(Model_User::class, $sut);
}
}

Answer 4

Found the working solution, would to share it despite the topic is old.
class_alias can substitute classes which are not autoloaded yet (works only if you use autoloading, not include/require files directly).
For example, our code:
class MyClass
{
public function someAction() {
StaticHelper::staticAction();
}
}
Our test:
class MyClassTest
{
public function __construct() {
// works only if StaticHelper is not autoloaded yet!
class_alias(StaticHelperMock::class, StaticHelper::class);
}
public function test_some_action() {
$sut = new MyClass();
$myClass->someAction();
}
}
Our mock:
class StaticHelperMock
{
public static function staticAction() {
// here implement the mock logic, e.g return some pre-defined value, etc
}
}
This simple solution doesn't need any special libs or extensions.

Answer 5

Mockery's Alias functionality can be used to mock public static methods
http://docs.mockery.io/en/latest/reference/creating_test_doubles.html#creating-test-doubles-aliasing

Answer 6

Another possible approach is with the Moka library:
$modelClass = Moka::mockClass('Model_User', [
'fromArray' => null,
'save' => null
]);
$modelClass::create('DATA');
$this->assertEquals(['DATA'], $modelClass::$moka->report('fromArray')[0]);
$this->assertEquals(1, sizeof($modelClass::$moka->report('save')));

Answer 7

One more approach:
class Experiment
{
public static function getVariant($userId, $experimentName)
{
$experiment = self::loadExperimentJson($experimentName):
return $userId % 10 > 5; // some sort of bucketing
}
protected static function loadExperimentJson($experimentName)
{
// ... do something
}
}
In my ExperimentTest.php
class ExperimentTest extends \Experiment
{
public static function loadExperimentJson($experimentName)
{
return "{
"name": "TestExperiment",
"variants": ["a", "b"],
... etc
}"
}
}
And then I would use it like so:
public function test_Experiment_getVariantForExperiment()
{
$variant = ExperimentTest::getVariant(123, 'blah');
$this->assertEquals($variant, 'a');
$variant = ExperimentTest::getVariant(124, 'blah');
$this->assertEquals($variant, 'b');
}

Answer 8

Testing static methods is generally considered as a bit hard (as you probably already noticed), especially before PHP 5.3.
Could you not modify your code to not use static a method ? I don't really see why you're using a static method here, in fact ; this could probably be re-written to some non-static code, could it not ?
For instance, could something like this not do the trick :
class Model_User extends Doctrine_Record
{
public function saveFromArray($userData)
{
$this->fromArray($userData);
$this->save();
}
}
Not sure what you'll be testing ; but, at least, no static method anymore...