bug #205 [HttpKernel] Move the backed enum value resolver deprecation…

… trigger to the constructor (ogizanagi)

This PR was merged into the 2.x-dev branch.

Discussion
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[HttpKernel] Move the backed enum value resolver deprecation trigger to the constructor

Since the controller arg resolvers are added to the `annotations.map` [file from the `FrameworkExtension`](symfony/symfony@feb5e62), the class was loaded during warmup and the deprec was triggered even if the class is not used in the app.

So let's move it to the constructor.

Commits
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60513b6 [HttpKernel] Move the backed enum value resolver deprecation trigger to the constructor

src/Bridge/Symfony/HttpKernel/Controller/ArgumentResolver/BackedEnumValueResolver.php

@@ -18,17 +18,6 @@
 use Symfony\Component\HttpKernel\ControllerMetadata\ArgumentMetadata;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
-// Suggest using Symfony 6.1+ resolver
-if (class_exists(SymfonyBackedEnumValueResolver::class)) {
-    trigger_deprecation(
-        'elao/enum',
-        '2.1',
-        'The "%s" class is deprecated with "symfony/http-kernel" >= 6.1, use "%s" instead.',
-        BackedEnumValueResolver::class,
-        SymfonyBackedEnumValueResolver::class
-    );
-}
-
 // Legacy (<6.1) resolver
 /**
  * Attempt to resolve backed enum cases from request attributes, for a route path parameter,
@@ -40,6 +29,20 @@
  */
 class BackedEnumValueResolver implements ArgumentValueResolverInterface
 {
+    public function __construct()
+    {
+        // Suggest using Symfony 6.1+ resolver
+        if (class_exists(SymfonyBackedEnumValueResolver::class)) {
+            trigger_deprecation(
+                'elao/enum',
+                '2.1',
+                'The "%s" class is deprecated with "symfony/http-kernel" >= 6.1, use "%s" instead.',
+                __CLASS__,
+                SymfonyBackedEnumValueResolver::class
+            );
+        }
+    }
+
     public function supports(Request $request, ArgumentMetadata $argument): bool
     {
         if (!is_subclass_of($argument->getType(), \BackedEnum::class)) {