Pest Installation And Syntax

Pest is a PHP testing framework with a concise functional syntax and tooling built around developer feedback. It runs on top of the PHPUnit ecosystem, so existing PHP testing knowledge remains useful.

Install It As A Development Dependency

Follow the current Pest installation guide for runtime requirements and Composer commands. Initialise the suite with the project-local binary and keep tests/Pest.php in version control.

composer require pestphp/pest --dev --with-all-dependencies
./vendor/bin/pest --init
./vendor/bin/pest

Describe Behaviour In Small Tests

Pest uses functions such as test() or it() and an expectation API. Keep the same engineering standards as PHPUnit: deterministic setup, clear behaviour, useful assertions, and appropriate integration coverage.

<?php

declare(strict_types=1);

function discount(int $totalPence): int
{
    return $totalPence >= 10_000 ? intdiv($totalPence, 10) : 0;
}

test('order receives ten percent discount at threshold', function (): void {
    expect(discount(10_000))->toBe(1_000);
});

Common Mistakes

• Choosing Pest only for shorter syntax while ignoring suite design.
• Using a global binary instead of the project dependency.
• Assuming every plugin is installed by default.
• Forgetting to check current Pest runtime requirements.

What To Practise

• Install and initialise Pest from official docs.
• Recognise test(), it(), and expect().
• Apply the same boundary decisions as PHPUnit.