PHPUnit_MockObject is the default mock object library for PHPUnit.
- PHP 5.6 is required but using the latest version of PHP is highly recommended
You can add this library as a local, per-project dependency to your project using Composer:
composer require phpunit/phpunit-mock-objects
If you only need this library during development, for instance to run your project's test suite, then you should add it as a development-time dependency:
composer require --dev phpunit/phpunit-mock-objects