phpunit

name	phpunit
description	PHPUnit PHP testing framework. Use for PHP testing.

PHPUnit

PHPUnit is the standard unit testing framework for the PHP ecosystem. Examples include usage in Laravel, Symfony, and WordPress.

When to Use

• PHP Application: The industry standard.
• TDD: Built-in support for mocking and code coverage.

Quick Start

<?php
use PHPUnit\Framework\TestCase;

final class StackTest extends TestCase
{
    public function testPushAndPop(): void
    {
        $stack = [];
        $this->assertEmpty($stack);

        array_push($stack, 'foo');
        $this->assertNotEmpty($stack);
        $this->assertEquals('foo', array_pop($stack));
    }
}

Core Concepts

Assertions

Methods like $this->assertTrue(), $this->assertSame(), $this->expectException().

Mock Objects

PHPUnit gives you control over the behavior of dependencies.

$stub = $this->createMock(SomeClass::class);
$stub->method('doSomething')->willReturn('foo');
$this->assertEquals('foo', $stub->doSomething());

Data Providers

Pass data to a test method (similar to parameterized tests).

#[DataProvider('additionProvider')]
public function testAdd(int $a, int $b, int $expected): void { ... }

Best Practices (2025)

Do:

• Use Strict Assertions: $this->assertSame() checks types (===), whereas assertEquals is loose (==). Strict is safer.
• Use Namespaces: Organize tests Tests\Unit\UserTest matching App\Models\User.
• PHPUnit 11 features: Use the new attributes #[Test] instead of /** @test */ annotations if on PHP 8.2+.

Don't:

• Don't test private methods: Test the public API. If a private method is complex, extract it to a new class.

References

• PHPUnit Documentation