Tests: switch to PHPUnit

[jrfnl]

Note: This PR will be easiest to review by looking at each commit individually.

Fixes #90

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Tests: switch to PHPUnit - set up the basics

• Composer: require PHPUnit instead of the Nette test framework
• Composer: adjust the scripts to run the tests via PHPUnit.
• GH Actions: adjust the workflow to run the tests via PHPUnit.
  Includes allowing for PHPUnit 9.x to be installed when testing against PHP 8.2.
• Add a PHPUnit configuration file.
• Allow for PHPUnit specific files in various places.
• Remove the Nette specific PHP ini file.

Tests: add test bootstrap and basic UnitTestCase

• The test bootstrap.php file has been crafted to allow for running the tests both via a Composer installed PHPUnit version, as well as running the tests via a PHPUnit PHAR file.
  The reason for this is, that as this application supports a wide range of PHP versions, a wide range of PHPUnit versions is needed to test against all the relevant PHP versions.
  When running the tests locally, this would mean running composer update between every test run, which gets tedious fast and slows development down.
  By explicitly supporting running the tests via a PHPUnit PHAR file, this extra step of running composer update between every test run on a different PHP version is eliminated.
• The UnitTestCase.php file is a bare bones PHPUnit TestCase file.
  This TestCase only contains a couple of methods to provide polyfills for PHPUnit assertions which have changed names across PHPUnit versions.
  An alternative would be to use something like the PHPUnit Polyfills package, however as that requires a minimum PHP version of PHP 5.4, that is not an option at this time.
  The polyfilled functions I added to the UnitTestCase are 100% based on the polyfills from the PHPUnit Polyfills and are tried and tested in that package (which I wrote, so I'm not violating copyright here ;-) ).

Note: the name UnitTestCase file has been chosen deliberately as this package is typically a package which could benefit from having both unit as well as integration tests and naming the file/class UnitTestCase allows for adding an IntegrationTestCase base class later on.

Tests: switch to using the PHPUnit test runner

Includes:

• Removing the @testCase annotations.
• Removing the require statements at the top of each test file.
  Instead the file loading will be handled via the bootstrap.php file for PHPUnit.
• Switching out usage of the Nette TestCase and replacing it with the PHP_Parallel_Lint\PhpParallelLint\Tests\UnitTestCase.
• Removing the test class instantiations and ->run() commands at the end of the test files in favour of letting the PHPUnit test runner handle this.

Tests: switch to using the PHPUnit assertions and expectations

Includes:

• Ensuring that assertions use strict type comparisons (assertSame() instead of equal).
• Uses a few polyfilled assertions/expectations from the UnitTestCase class to ensure the tests can run without problems on the needed range of PHPUnit versions.
• Includes minor adjustments to how the "paths" are passed in the ManagerRunTest as the tests for Nette were run from the tests directory, while PHPUnit is run from the project root directory.

Tests: use the PL_TESTROOT constant

... as declared in the test bootstrap file to allow for more stability when test files get moved around.

Tests: re-organize test directory structure

• Move all existing test file in a Unit subdirectory as these are unit tests.
  This allows for more easily adding a second set of (integration) tests at a later point in time.
• Let the subdirectory structure of the tests\Unit directory reflect the structure of the src directory.
• Let the class names of the test files reflect the class name + method name of the method under test.

[grogy]

I am happy. Your commits are as a guide "How to replace Nette Tester with PHPUnit"

[grogy]

Thank you 💙

[jrfnl]

Your commits are as a guide "How to replace Nette Tester with PHPUnit"

😄 Nice! Oh and if it weren't for the fact that PHP 5.3 is still supported in this package, I would have added the PHPUnit Polyfills as well instead of having our "own" polyfilled functions in the TestCase class.

We could maybe consider dropping support for PHP 5.3 in the 2.0 version ?