Installing PHPUnit

Before we write any tests, we need to get PHPUnit installed and ready to run.

You'll need Composer installed on your machine to follow along. If you haven’t already, visit getcomposer.org/download for installation instructions.

Step 1: Create a project folder

Start by creating a new directory for your project and navigating into it:

mkdir testing-php
cd testing-php

Step 2: Install PHPUnit with Composer

Install PHPUnit as a development dependency:

composer require --dev phpunit/phpunit

Composer will automatically generate a composer.json file and download PHPUnit into the vendor/ directory.

You can now run PHPUnit using:

./vendor/bin/phpunit --version

If you see a version number, your setup is working.

Why install locally instead of globally?

Installing PHPUnit locally (per project) is the best practice because:

• Each project can use its own PHPUnit version
• It keeps your setup portable and reproducible
• It avoids conflicts with other global tools

You can install it globally if needed:

composer global require phpunit/phpunit

…but we won’t use that approach in this course.

Step 3: Run PHPUnit

Try running PHPUnit now:

./vendor/bin/phpunit

You won’t have any tests yet, but PHPUnit should run and tell you so. That means your setup is complete.

In the next lesson, you’ll create your first test file and see it in action.