Unit testing is essential for maintaining code quality in PHP projects. PHPUnit is the most widely used testing framework.

Setting Up PHPUnit

Install PHPUnit via Composer:

composer require --dev phpunit/phpunit ^10.0

Writing a Test

Example test for a Calculator class:

use PHPUnit\Framework\TestCase;

class CalculatorTest extends TestCase {
    public function testAddition() {
        $calc = new Calculator();
        $this->assertEquals(4, $calc->add(2, 2));
    }
}

Running Tests

Execute tests with:

vendor/bin/phpunit --colors=always

Best Practices

  • Write small, isolated tests
  • Use mocks and stubs for dependencies
  • Keep tests readable and maintainable

Conclusion

Integrating PHPUnit into your workflow ensures your PHP code remains robust and prevents regressions.