feature #34872 [FrameworkBundle] Added flex-compatible default implementations for MicroKernelTrait::registerBundles() and getProjectDir() (nicolas-grekas)

This PR was merged into the 5.1-dev branch.

Discussion
----------

[FrameworkBundle] Added flex-compatible default implementations for `MicroKernelTrait::registerBundles()` and `getProjectDir()`

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

I think it's safe now to migrate some flex-based defaults from the recipe to the bundle.
No BC break here as all existing kernels already redefine this method.

Commits
-------

a689807387 [FrameworkBundle] Added flex-compatible default implementations for `MicroKernelTrait::registerBundles()` and `getProjectDir()`

Author: nicolas-grekas

CHANGELOG.md

@@ -7,6 +7,7 @@ CHANGELOG
  * Marked `MicroKernelTrait::configureRoutes()` as `@internal` and `@final`.
  * Deprecated not overriding `MicroKernelTrait::configureRouting()`.
  * Added a new `mailer.message_bus` option to configure or disable the message bus to use to send mails.
+ * Added flex-compatible default implementations for `MicroKernelTrait::registerBundles()` and `getProjectDir()`
 
 5.0.0
 -----

Kernel/MicroKernelTrait.php

@@ -72,6 +72,27 @@ protected function configureRouting(RoutingConfigurator $routes): void
      */
     abstract protected function configureContainer(ContainerBuilder $c, LoaderInterface $loader);
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getProjectDir(): string
+    {
+        return \dirname((new \ReflectionObject($this))->getFileName(), 2);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function registerBundles(): iterable
+    {
+        $contents = require $this->getProjectDir().'/config/bundles.php';
+        foreach ($contents as $class => $envs) {
+            if ($envs[$this->environment] ?? $envs['all'] ?? false) {
+                yield new $class();
+            }
+        }
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -100,8 +121,8 @@ public function registerContainerConfiguration(LoaderInterface $loader)
             }
 
             $this->configureContainer($container, $loader);
-
             $container->addObjectResource($this);
+            $container->fileExists($this->getProjectDir().'/config/bundles.php');
         });
     }