Add PHPMD

.github/workflows/code_check.yml

@@ -44,6 +44,24 @@ jobs:
       - name: Run PHPUnit
         run: vendor/bin/phpunit
 
+  phpmd:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 7.4
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress --no-suggest
+
+      - name: Run PHPMD
+        run: vendor/bin/phpmd src github phpmd.xml
+
   php-cs-fixer:
     runs-on: ubuntu-latest
 
@@ -66,3 +84,4 @@ jobs:
         uses: stefanzweifel/git-auto-commit-action@v4
         with:
           commit_message: Fix styling
+

composer.json

@@ -11,7 +11,8 @@
     "require-dev": {
         "phpunit/phpunit": "^9.6",
         "friendsofphp/php-cs-fixer": "^3.58",
-        "phpstan/phpstan": "^1.11"
+        "phpstan/phpstan": "^1.11",
+        "phpmd/phpmd": "^2.15"
     },
     "autoload": {
         "psr-4": {