Fix package to work on PHP 7.3 (do not use PHP 7.4 syntax)

.github/workflows/ci.yml

@@ -79,4 +79,18 @@ jobs:
           composer update --${{ matrix.dependency-version }} --prefer-dist --no-interaction --no-suggest --ignore-platform-req=php
 
       - name: Execute tests
-        run: vendor/bin/phpunit
+        run: composer test
+
+      - name: Check .php files for syntax errors
+        run: composer php:syntax -- --checkstyle | cs2pr
+
+      - uses: actions/cache@v3
+        id: cache-db
+        with:
+          path: ~/.symfony/cache
+          key: db
+
+      - name: Check composer dependencies for known security issues
+        uses: symfonycorp/security-checker-action@v3
+        with:
+          lock: ./composer.lock

composer.json

@@ -21,6 +21,7 @@
     "league/event": "^2.1"
   },
   "require-dev": {
+    "php-parallel-lint/php-parallel-lint": "^1.3",
     "phpunit/phpunit": "^9.5"
   },
   "autoload": {
@@ -38,6 +39,7 @@
     "illuminate/container": "Hold dependencies to be injected in commands constructors"
   },
   "scripts": {
+    "php:syntax": "parallel-lint . --blame --colors --exclude vendor",
     "test": "phpunit"
   },
   "extra": {

src/Objects/Update.php

@@ -33,7 +33,8 @@
  */
 class Update extends BaseObject
 {
-    protected ?string $updateType = null;
+    /** @var string|null Cached type of thr Update () */
+    protected $updateType = null;
 
     /**
      * {@inheritdoc}
@@ -91,7 +92,7 @@ public function isType($type)
      */
     public function objectType(): ?string
     {
-        return $this->updateType ??= $this->except('update_id')
+        return $this->updateType ?: $this->except('update_id')
             ->keys()
             ->first();
     }