Installation

Let’s install PHP through XAMPP. If needed, add it to $PATH

echo "export PATH=/opt/lampp/bin:$PATH" >> ~/.bashrc

Option 1

Install Composer and require PHPUnit as a development dependency:

composer require --dev phpunit/phpunit

… Run the test! Run PHPUnit from the project’s directory

./vendor/bin/phpunit test/test.php

Option 2

Download the PHPUnit PHAR file and move it to your user-level scripts directory:

wget https://phar.phpunit.de/phpunit.phar && chmod +x phpunit.phar && sudo mv phpunit.phar ~/bin/phpunit

… Run the test! Run PHPUnit from user-level scripts directory

phpunit test/test.php

Unit testing sample

Function example src/functions.php

<?php
function helloWorld() {
    return "Hello, World!";
}

Test example test/test.php

<?php
use PHPUnit\Framework\TestCase;

class FunctionsTest extends TestCase
{
    public function testHelloWorld()
    {
        require 'src/functions.php';
        $this->assertEquals("Hello, World!", helloWorld());
    }
}

Assumed project structure

myProject/
├── src
│   └── functions.php
└── test
    └── test.php