PHPUnit: allow for PHPUnit 10 + add separate configuration

The PHPunit configuration file specification has undergone changes in PHPUnit 9.3, 10.0 and 10.1.

Most notably:
* In PHPUnit 9.3, the manner of specifying the code coverage configuration has changed.
* In PHPUnit 10.0, a significant number of attributes of the `<phpunit>` element were removed or renamed.
* In PHPUnit 10.1, there is another change related to the code coverage configuration + the ability to fail builds on deprecations/warnings/notices is brought back.

While the `--migrate-configuration` command can upgrade a configuration for the changes in the format made in PHPUnit 9.3, some of the changes in the configuration format in PHPUnit 10 don't have one-on-one replacements and/or are not taken into account.

As this package is used in the CI pipeline for other packages, it is important for this package to be ready for new PHP releases _early_, so failing the test suite on deprecatios/notices and warnings is appropriate.

With that in mind, I deem it more appropriate to have a dedicated PHPUnit configuration file for PHPUnit 10 to ensure the test run will behave as intended.

This commit adds this dedicated configuration file for PHPUnit 10.1+.

Includes:
* Ignoring the new file for package archives.
* Allowing for a local override file.
* Adding scripts to the `composer.json` file to run the tests using this new configuration file and make the use of the separate config make more obvious for contributors.
* Updating the GH Actions `test` workflow to trigger the tests on PHPUnit 10 with this configuration file.

Ref:
* https://github.com/sebastianbergmann/phpunit/blob/main/ChangeLog-10.0.md#1000---2023-02-03
* sebastianbergmann/phpunit 5196
* sebastianbergmann/phpunit@fb6673f

Author: jrfnl

Diff for: .gitattributes

@@ -5,15 +5,16 @@
 # https://www.reddit.com/r/PHP/comments/2jzp6k/i_dont_need_your_tests_in_my_production
 # https://blog.madewithlove.be/post/gitattributes/
 #
-.gitattributes   export-ignore
-.gitignore       export-ignore
-appveyor.yml     export-ignore
-box.json         export-ignore
-phpcs.xml.dist   export-ignore
-phpunit.xml.dist export-ignore
-/.github/        export-ignore
-/doc/            export-ignore
-/tests/          export-ignore
+.gitattributes     export-ignore
+.gitignore         export-ignore
+appveyor.yml       export-ignore
+box.json           export-ignore
+phpcs.xml.dist     export-ignore
+phpunit.xml.dist   export-ignore
+phpunit10.xml.dist export-ignore
+/.github/          export-ignore
+/doc/              export-ignore
+/tests/            export-ignore
 
 #
 # Auto detect text files and perform LF normalization

Diff for: .github/workflows/test.yml

@@ -152,9 +152,18 @@ jobs:
       - name: 'Integration test 2 - linting own code'
         run: ./parallel-lint --exclude vendor --exclude tests/fixtures .
 
-      - name: 'Run unit tests'
+      - name: Grab PHPUnit version
+        id: phpunit_version
+        run: echo "VERSION=$(vendor/bin/phpunit --version | grep --only-matching --max-count=1 --extended-regexp '\b[0-9]+\.[0-9]+')" >> $GITHUB_OUTPUT
+
+      - name: "Run unit tests (PHPUnit < 10)"
+        if: ${{ ! startsWith( steps.phpunit_version.outputs.VERSION, '10.' ) }}
         run: composer test
 
+      - name: "Run unit tests (PHPUnit < 10)"
+        if: ${{ startsWith( steps.phpunit_version.outputs.VERSION, '10.' ) }}
+        run: composer test10
+
       - uses: actions/download-artifact@v4
         with:
           name: parallel-lint-phar

Diff for: .gitignore

@@ -5,3 +5,4 @@ composer.lock
 phpcs.xml
 .phpunit.result.cache
 phpunit.xml
+phpunit10.xml

Diff for: composer.json

@@ -26,7 +26,7 @@
         "jakub-onderka/php-parallel-lint": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8.36 || ^5.7.21 || ^6.0 || ^7.0 || ^8.0 || ^9.0",
+        "phpunit/phpunit": "^4.8.36 || ^5.7.21 || ^6.0 || ^7.0 || ^8.0 || ^9.0 || ^10.1",
         "php-parallel-lint/php-console-highlighter": "0.* || ^1.0",
         "php-parallel-lint/php-code-style": "^2.0"
     },
@@ -54,10 +54,14 @@
     ],
     "scripts": {
         "test": "@php ./vendor/phpunit/phpunit/phpunit --no-coverage",
-        "coverage": "@php ./vendor/phpunit/phpunit/phpunit"
+        "test10": "@php ./vendor/phpunit/phpunit/phpunit -c phpunit10.xml.dist --no-coverage",
+        "coverage": "@php ./vendor/phpunit/phpunit/phpunit",
+        "coverage10": "@php ./vendor/phpunit/phpunit/phpunit -c phpunit10.xml.dist"
     },
     "scripts-descriptions": {
-        "test": "Run all tests!",
-        "coverage": "Run all tests *with code coverage*"
+        "test": "Run all tests! ( PHPUnit < 10)",
+        "test10": "Run all tests! ( PHPUnit 10+)",
+        "coverage": "Run all tests *with code coverage* ( PHPUnit < 10)",
+        "coverage10": "Run all tests *with code coverage* ( PHPUnit 10+)"
     }
 }

Diff for: phpunit10.xml.dist

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.1/phpunit.xsd"
+        backupGlobals="true"
+        beStrictAboutTestsThatDoNotTestAnything="true"
+        bootstrap="./tests/bootstrap.php"
+        colors="true"
+        displayDetailsOnTestsThatTriggerErrors="true"
+        displayDetailsOnTestsThatTriggerWarnings="true"
+        displayDetailsOnTestsThatTriggerNotices="true"
+        displayDetailsOnTestsThatTriggerDeprecations="true"
+        displayDetailsOnIncompleteTests="true"
+        displayDetailsOnSkippedTests="true"
+        failOnWarning="true"
+        failOnNotice="true"
+        failOnDeprecation="true"
+        stopOnFailure="false"
+    >
+
+    <testsuites>
+        <testsuite name="Unittests">
+            <directory suffix="Test.php">tests/Unit</directory>
+        </testsuite>
+    </testsuites>
+
+    <source>
+        <include>
+            <directory suffix=".php">./src/</directory>
+        </include>
+    </source>
+
+    <coverage includeUncoveredFiles="true" ignoreDeprecatedCodeUnits="true">
+        <report>
+            <clover outputFile="build/logs/clover.xml"/>
+            <text outputFile="php://stdout" showOnlySummary="true"/>
+        </report>
+    </coverage>
+
+</phpunit>