To explain test doubles in PHPUnit by using various examples.

For details, please read the source code under folder ./unit and run the tests using PHPUnit.

Usage

First, run the following command to install/update Composer packages:

composer update -n

Now we can run PHPUnit tests:

./vendor/bin/phpunit

Version Matrix

Following table shows the versions of PHP and PHPUnit used to run the tests of this project via GitHub Actions:

PHP Versions	PHPUnit Versions
PHP 7.3	PHPUnit 9
PHP 7.4	PHPUnit 9
PHP 8.0	PHPUnit 9
PHP 8.1	PHPUnit 10
PHP 8.2	PHPUnit 11
PHP 8.3	PHPUnit 11

References

• test doubles in PHPUnit: The official documentation.
• StackOverflow: Mocks vs Stubs in PHPUnit: Effective comparison of dummies, stubs, mocks, and spies in PHPUnit, although the examples are outdated.