PHP Testing Skill | Agent Skills

<objective> Covers testing a framework-agnostic PHP project with PHPUnit 13 (class-based, xUnit-style, attributes only — annotations like @test/@dataProvider were removed in PHPUnit 12) or Pest 5 (closure-based, expressive, adds browser/architecture/mutation testing, built on PHPUnit 13), both of which run on PHPUnit's engine and require PHP 8.4+.

Includes a decision matrix for choosing between the two (team preference, not capability), plus templates for phpunit.xml, Pest.php setup, and test doubles (stubs, mocks, fixtures, coverage).

Do NOT use this skill for Laravel test helpers such as RefreshDatabase or HTTP testing — those are covered by laravel-expert's laravel-testing skill. Do NOT use it for static analysis or formatting tooling — that is php-quality-tooling. </objective>

PHP Testing

Two frameworks, one engine. Pest is a layer over PHPUnit — both need PHP 8.4+ and share the same runner and assertions underneath.

Agent Workflow (MANDATORY)

Before ANY implementation, spawn 3 agents in parallel, one Agent call each with a name:

fuse-ai-pilot:explore-codebase - Detect existing framework (phpunit.xml vs Pest.php), test layout, PHP version
fuse-ai-pilot:research-expert - Verify latest PHPUnit 13 / Pest 5 docs via Context7/Exa
mcp__context7__query-docs - Check attribute names, test-double API, config schema

After implementation, run fuse-ai-pilot:sniper for validation.

Overview

| Framework | Style | Strength | |-----------|-------|----------| | PHPUnit 13 | Class-based, xUnit | Enterprise baseline, explicit, widest tooling/CI support | | Pest 5 | Closure-based, expressive | Modern DX, browser + arch + mutation testing, less boilerplate |

Pest 5 runs on PHPUnit 13's engine, so PHPUnit knowledge transfers directly. The choice is about ergonomics and team preference, not capability.

Critical Rules

PHP 8.4+ required - Both PHPUnit 13 and Pest 5 drop PHP 8.3 (stay on PHPUnit 12 / Pest 4 for 8.3)
Attributes only, no annotations - PHPUnit 12 removed docblock annotations (@test, @dataProvider)
Data providers are public static - Non-static providers no longer work
createStub() is not configurable - Configure expectations only on createMock(); any() is hard-deprecated in PHPUnit 13 — use a stub or a real count (once(), exactly(n))
One framework per project - Pest or PHPUnit, not both driving the same suite
Mock at boundaries - Network/DB/clock, never internal implementation detail

Decision Guide

Choosing a framework? (non-Laravel)
├── Enterprise / strict CI / mixed team → PHPUnit 13 (explicit, ubiquitous)
├── Modern DX, greenfield, small team → Pest 5 (concise, expressive)
├── Need browser / architecture / mutation testing out of the box → Pest 5
└── Migrating a large PHPUnit suite → stay PHPUnit, or drift-migrate to Pest

Honest note: PHPUnit is the enterprise/CI baseline; Pest has strong community momentum but that trend is not normative. Either is a correct, well-supported choice — pick per team, not per hype.

→ Full matrix in references/choosing-framework.md

Reference Guide

Concepts

| Topic | Reference | Load when | |-------|-----------|-----------| | Framework choice | references/choosing-framework.md | Deciding PHPUnit vs Pest | | PHPUnit 13 | references/phpunit-12.md | Writing PHPUnit tests | | Pest 5 | references/pest-4.md | Writing Pest tests | | Annotation migration | references/annotations-to-attributes.md | Upgrading pre-12 tests |

Templates

| Template | Use Case | |----------|----------| | references/templates/phpunit-xml.md | phpunit.xml + first TestCase | | references/templates/pest-setup.md | Pest.php + first Pest tests | | references/templates/test-doubles.md | Stubs, mocks, fixtures, coverage |

Quick Start

PHPUnit 13

use PHPUnit\Framework\TestCase;

final class GreeterTest extends TestCase
{
    public function testGreets(): void
    {
        $this->assertSame('Hi, Al', (new Greeter)->greet('Al'));
    }
}

Pest 5

it('greets', function () {
    expect((new Greeter)->greet('Al'))->toBe('Hi, Al');
});

Agent Skills: PHP Testing

Install this agent skill to your local

Skill Files