README

phptailors/singleton-testing

PHPUnit extension for testing implementations of phptailors/singleton-interface.

Installation

composer require --dev "phptailors/singleton-testing:^1.0"
composer require --dev "phpunit/phpunit"

Usage

<?php

use PHPUnit\Framework\TestCase;
use Tailors\Testing\Lib\Singleton\AssertIsSingletonTrait;

final class MySingletonTest extends TestCase
{
    use AssertIsSingletonTrait;

    public function testMySingletonIsSingleton(): void
    {
        $this->assertIsSingleton(MySingleton::class);
    }
}

How a class is tested

The following tests are performed by assertIsSingleton($class):

1. Assert that the the provided string $class is a class.
2. Assert that $class has private constructor.
3. Assert that $class has public static method getInstance().
4. Assert that $class::getInstance() is callable.
5. Assert that $class::getInstance() returns an instance of $class.
6. Assert that $class::getInstance() is idempotent.
7. Assert that $class is not cloneable.
8. Assert that it throws Tailors\Lib\Singleton\SingletonException on unserialize().

The name of the getInstance() method may be customized, for example:

    $this->assertIsSingleton(MySingleton::class, getInstance: "getSingleInstance")

will use getSingleInstance instead of getInstance.