Add types to private and internal properties

Author: nicolas-grekas

Matcher/Dumper/CompiledUrlMatcherTrait.php

@@ -30,11 +30,7 @@ trait CompiledUrlMatcherTrait
     private array $staticRoutes = [];
     private array $regexpList = [];
     private array $dynamicRoutes = [];
-
-    /**
-     * @var callable|null
-     */
-    private $checkCondition;
+    private ?\Closure $checkCondition;
 
     public function match(string $pathinfo): array
     {

Matcher/UrlMatcher.php

@@ -260,7 +260,7 @@ protected function mergeDefaults(array $params, array $defaults): array
      */
     protected function getExpressionLanguage()
     {
-        if (null === $this->expressionLanguage) {
+        if (!isset($this->expressionLanguage)) {
             if (!class_exists(ExpressionLanguage::class)) {
                 throw new \LogicException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed. Try running "composer require symfony/expression-language".');
             }

RouteCollection.php

@@ -37,7 +37,7 @@ class RouteCollection implements \IteratorAggregate, \Countable
     /**
      * @var array<string, Alias>
      */
-    private $aliases = [];
+    private array $aliases = [];
 
     /**
      * @var array<string, ResourceInterface>