check php syntax on all supported PHP versions

.github/workflows/check-php-syntax.yml

@@ -0,0 +1,23 @@
+name: Check PHP syntax
+
+on: [ push, pull_request ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php-versions: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
+    steps:
+      # Install PHP interpreter
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+
+      # Checkout source repository
+      - name: checkout repo
+        uses: actions/checkout@v3
+
+      # Lint every PHP source file using PHP interpreter
+      - run: composer run check-syntax

.github/workflows/php.yml

@@ -5,7 +5,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-versions: [ '8.2', '8.3' ]
+        php-versions: [ '8.3' ]
     steps:
       - uses: actions/checkout@v3
       - uses: shivammathur/setup-php@v2

composer.json

@@ -29,7 +29,8 @@
 	"scripts": {
 		"make-pot": "wp i18n make-pot . languages/mailchimp-for-wp.pot --exclude=assets/js",
 		"test": "phpunit tests/",
-		"codestyle": "phpcs -n -s"
+		"codestyle": "phpcs -n -s",
+	    "check-syntax": "find . -name '*.php' -not -path './vendor/*' -not -path './var/cache/*' -print0 | xargs -0 -n1 php -l"
 	},
 	"config": {
 		"allow-plugins": {