Testing in PHP: Overview of Frameworks and Tools (PHPUnit, Pest, Codeception)

Introduction to Testing PHP Applications

Testing is an integral part of professional PHP development. It helps identify errors at early stages, simplifies refactoring, and increases code stability. The PHP ecosystem has a powerful set of tools: from the classic PHPUnit to modern frameworks like Pest and specialized utilities for coverage analysis and mutation testing.

In this article, we will review the key frameworks and tools that will help you organize high-quality testing for PHP projects.

PHPUnit — The Foundation of Testing

PHPUnit is the de facto standard for unit testing in PHP. It supports all modern features: assertions, fixtures (setUp/tearDown), data providers, exception testing, stubs, and mocks.

Installation via Composer:

composer require --dev phpunit/phpunit

Example of a simple test for a calculator class:

<?phpuse PHPUnit\\Framework\\TestCase;

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

    /** @dataProvider additionProvider */    public function testWithDataProvider($a, $b, $expected)    {        $calculator = new Calculator();        $this->assertEquals($expected, $calculator->add($a, $b));    }

    public function additionProvider(): array    {        return [            [0, 0, 0],            [1, 1, 2],            [-1, 1, 0],        ];    }}

Key PHPUnit features:

• Assertions: assertEquals, assertTrue, assertCount, assertInstanceOf, and dozens of others.
• Fixtures: setUp() and tearDown() methods for preparing and cleaning up the environment.
• Data Providers: @dataProvider annotation for running one test with different data sets.
• Exception Testing: expectException() and expectExceptionMessage().
• Stubs and Mocks: createMock() and getMockBuilder() for isolating the code under test.

Pest — Elegant and Modern

Pest is a testing framework built on top of PHPUnit, but with a more concise and expressive syntax. It is inspired by Jest (JavaScript) and is great for projects where test readability is important.

Installation:

composer require --dev pestphp/pest

Example of the same test in Pest:

<?php

use function Pest\\Faker\\fake;

test('addition works correctly', function () {    $calculator = new Calculator();    expect($calculator->add(2, 2))->toBe(4);});

dataset('numbers', [    [0, 0, 0],    [1, 1, 2],    [-1, 1, 0],]);

test('addition with data provider', function ($a, $b, $expected) {    $calculator = new Calculator();    expect($calculator->add($a, $b))->toBe($expected);})->with('numbers');

Advantages of Pest:

• Minimal boilerplate code — no need to create test classes.
• Built-in functions expect(), test(), it() for natural language descriptions.
• Automatic registration of tests from global functions.
• Support for nested groups (describe) and architectural tests.

Codeception — For Integration and BDD Testing

Codeception is a universal framework that combines unit, functional, integration, and acceptance tests. It is especially popular for testing web applications (Laravel, Symfony, Yii) and APIs.

Installation:

composer require --dev codeception/codeception

Example of an acceptance test for logging into a website:

<?php$I = new AcceptanceTester($scenario);$I->amO