So you have an Apple Mac and want to get started in the wonderful world of Unit Testing. Writing a unit test is very straightforward, yet most open source software projects have very limited unit tests available so always welcome more and it could be an easy way to contribute to the project.
Like I said writing your first unit test is pretty straightforward, it can be something as simple as just checking if a constant is set $this->assertFalse( defined( 'WC_TESTING_DEFINE_FUNCTION' ) );. Yet when it comes time to run the actual test you quickly discover that you need to have some software installed on your machine to run this, PHPUnit in WooCommerce’s case.
Then you head over to https://phpunit.de/getting-started.html and copy and paste the command and find that it does not work on your Mac because Mac OSX does not ship with wget installed by default. Then you search for installing wget on your mac and you go into a deep rabbit hole of having to install all sorts of software just to get it working.
Luckily there is a simpler way, simply copy and paste the command below into your console to have PHPUnit installed.
php -r "copy('https://phar.phpunit.de/phpunit.phar', 'phpunit.phar');"
chmod +x phpunit.phar
sudo mv phpunit.phar /usr/local/bin/phpunit