Downgrade to PHP 7.4, move from Pest to PHPUnit, establish CI (#25)

- Downgrades the lib to PHP 7.4
- Adds 'Check PHP CS == 7.4' step to GitHub Actions
- Replaces Pest with PHPUnit
- Rewrites RmStep tests in PHPUnit 
- Adds matrix unit tests step for all operating systems and all PHP
versions >= 7.4

 ### Caveats

- Dependencies versions are wildcards. This is inherently unstable, but
our true goal is to have stable 7.0 support. Establishing fixed versions
is a tedious job that does not seem crucial at this temporary step.
- Unit tests should include `prefer-lowest` as one of the arguments in
the `dependency_version` list. This will allow for the broadest version
support. But at this point in time it fails at 7.4. Fixing this serves
little purpose as, see logic above.
- Although we know PHPUnit 6.5 should be used, since this is the newest
versions supporting PHP == 7.0, PHPUnit 9.6 is used here. This is due to
all lower versions throwing the pesky `PHP Fatal error: Cannot acquire
reference to $GLOBALS`. This is still a step in the right direction as
writing PHPUnit tests in 9.6 and then downgrading them to 6.5 is still
easier, than writing in Pest and then going for PHPUnit 6.5.
- It should be analyzed if it is in fact beneficial to run the matrix
with each pull/pr. Alternatives: cron, only pr and more.


Co-authored-by: Adam Zieliński <[email protected]>

.github/workflows/ci.yml

@@ -0,0 +1,62 @@
+name: CI
+
+on:
+  push:
+    branches:
+    - trunk
+  pull_request:
+
+jobs:
+  php-cs-check:
+    name: 'PHP 7.4 compatibility (via PHP Code Sniffer)'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 7.4
+          tools: composer:v2
+          coverage: xdebug
+
+      - name: Install Dependencies
+        run: composer install --no-interaction --prefer-dist --optimize-autoloader
+
+      - name: Check PHP version compatibility
+        uses: pantheon-systems/phpcompatibility-action@v1
+        with:
+          skip-php-setup: true
+          test-versions: 7.4-
+          paths: ${{ github.workspace }}/src
+
+  test-unit:
+    needs: [php-cs-check]
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: true
+      matrix:
+        os: [ ubuntu-latest, macos-latest, windows-latest ]
+        php: [ '7.4', '8.0', '8.1', '8.2', '8.3' ]
+        dependency_version: [ prefer-stable ]
+
+    name: ${{ matrix.os }} - PHP ${{ matrix.php }} - ${{ matrix.dependency_version }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          tools: composer:v2
+          coverage: none
+
+      - name: Install PHP dependencies
+        run: composer update --${{ matrix.dependency_version }} --no-interaction --prefer-dist --optimize-autoloader
+
+      - name: Run tests
+        run: ./vendor/bin/phpunit --testdox

composer.json

@@ -1,31 +1,40 @@
 {
+  "prefer-stable": true,
   "require": {
-    "json-mapper/json-mapper": "^2.21",
-    "symfony/event-dispatcher": "^7.0",
-    "symfony/filesystem": "^7.0",
-    "symfony/process": "^7.0",
-    "symfony/http-client": "^7.0",
-    "symfony/http-kernel": "^7.0",
-    "pimple/pimple": "^3.0",
-    "psr/simple-cache": "^3.0",
-    "opis/json-schema": "^2.3"
+    "json-mapper/json-mapper": "*",
+    "symfony/event-dispatcher": "*",
+    "symfony/filesystem": "*",
+    "symfony/process": "*",
+    "symfony/http-client": "*",
+    "symfony/http-kernel": "*",
+    "pimple/pimple": "*",
+    "psr/simple-cache": "*",
+    "opis/json-schema": "*"
   },
   "require-dev": {
-    "pestphp/pest": "^2.33",
-    "nette/php-generator": "^4.1",
-    "jane-php/json-schema": "^7.6",
-    "bamarni/composer-bin-plugin": "^1.8"
+    "phpunit/phpunit": "*",
+    "squizlabs/php_codesniffer":"*",
+    "nette/php-generator": "*",
+    "jane-php/json-schema": "*",
+    "bamarni/composer-bin-plugin": "*",
+    "wp-coding-standards/wpcs": "3.0"
   },
   "config": {
     "optimize-autoloader": true,
     "preferred-install": "dist",
     "allow-plugins": {
-      "pestphp/pest-plugin": true,
       "php-http/discovery": true,
-      "bamarni/composer-bin-plugin": true
+      "bamarni/composer-bin-plugin": true,
+      "dealerdirect/phpcodesniffer-composer-installer": true
+    },
+    "platform": {
+      "php": "7.4"
     }
   },
   "autoload": {
+    "classmap": [
+      "src/"
+    ],
     "psr-4": {
       "WordPress\\": "src/WordPress",
       "Symfony\\Component\\Process\\": "vendor/symfony/process"
@@ -35,5 +44,8 @@
       "src/WordPress/Zip/functions.php",
       "src/WordPress/Streams/stream_str_replace.php"
     ]
+  },
+  "scripts": {
+    "phpcs": "phpcs --standard=WordPress"
   }
 }