Deep Closure Comparator

A Composer library that provides a PHPUnit comparator to assert equality of closures. It can be used to perform deep evaluation of closures, e.g. as part of objects. Closures are compared using their serialized value, which is calculated by the opis/closure library.

🔥 Installation

composer require --dev eliashaeussler/deep-closure-comparator

⚡ Usage

Instead of using the self::assertEquals() method of a PHPUnit test case, use the assertEquals method that is shipped within the DeepClosureAssert class:

use EliasHaeussler\DeepClosureComparator\DeepClosureAssert;
use PHPUnit\Framework\TestCase;

final class Foo
{
    public function __construct(
        public ?\Closure $bar = null,
    ) {}
}

final class FooTest extends TestCase
{
    public function testSomething(): void
    {
        $expected = new Foo();
        $expected->bar = static fn() => 'foo';

        $actual = new Foo();
        $actual->bar = static fn() => 'foo';

        DeepClosureAssert::assertEquals($expected, $actual);
    }
}

Or, in other words:

-self::assertEquals($expected, $actual);
+DeepClosureAssert::assertEquals($expected, $actual);

[!NOTE] Closures are compared using their serialized representation. This is done by the opis/closure library, which provides mechanisms to deep inspect and serialize given closures. More information can be found in the official documentation of this library.

🧑‍💻 Contributing

Please have a look at CONTRIBUTING.md.

💎 Credits

This project developed from a hardened implementation detail in the sebastian/comparator library, as part of PHPUnit's supply chain. With the introduction of a new ClosureComparator, comparing closures got a lot more difficult. Finally, @tstarling suggested parts of the actual implementation of this deep-closure-comparator library. Thank you very much for your support!

⭐ License

This project is licensed under GNU General Public License 3.0 (or later).