feature #31202 [FrameworkBundle] WebTestCase KernelBrowser::getContainer null return type (Simperfit)

This PR was merged into the 4.4 branch.

Discussion
----------

[FrameworkBundle] WebTestCase KernelBrowser::getContainer null return type

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | yes <!-- don't forget to update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | #25920  <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        |  <!-- required for new features -->

<!--
Write a short README entry for your feature/bugfix here (replace this comment block.)
This will help people understand your PR and can be used as a start of the Doc PR.
Additionally:
 - Bug fixes must be submitted against the lowest branch where they apply
   (lowest branches are regularly merged to upper ones so they get the fixes too).
 - Features and deprecations must be submitted against the master branch.
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As @stof suggested in the #25920 I started deprecating the behaviour of returning null when the container is non booted / null.

If this is not wanted we should close both the PR and the issue ;).

Commits
-------

e169e1a4d5 [FrameworkBundle] WebTestCase KernelBrowser::getContainer null return type

UPGRADE-4.4.md

@@ -148,6 +148,7 @@ HttpKernel
    fallback directories. Resources like service definitions are usually loaded relative to the
    current directory or with a glob pattern. The fallback directories have never been advocated
    so you likely do not use those in any app based on the SF Standard or Flex edition.
+ * Getting the container from a non-booted kernel is deprecated
 
 Lock
 ----

UPGRADE-5.0.md

@@ -288,6 +288,7 @@ HttpFoundation
    use `Symfony\Component\Mime\FileinfoMimeTypeGuesser` instead.
  * `ApacheRequest` has been removed, use the `Request` class instead.
  * The third argument of the `HeaderBag::get()` method has been removed, use method `all()` instead.
+ * Getting the container from a non-booted kernel is not possible anymore.
 
 HttpKernel
 ----------

src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php

@@ -127,11 +127,15 @@ abstract class KernelTestCase extends TestCase
     protected static function ensureKernelShutdown()
     {
         if (null !== static::$kernel) {
-            $container = static::$kernel->getContainer();
-            static::$kernel->shutdown();
-            static::$booted = false;
-            if ($container instanceof ResetInterface) {
-                $container->reset();
+            $isBooted = (new \ReflectionClass(static::$kernel))->getProperty('booted');
+            $isBooted->setAccessible(true);
+            if ($isBooted->getValue(static::$kernel)) {
+                $container = static::$kernel->getContainer();
+                static::$kernel->shutdown();
+                static::$booted = false;
+                if ($container instanceof ResetInterface) {
+                    $container->reset();
+                }
             }
         }
         static::$container = null;

src/Symfony/Bundle/FrameworkBundle/Tests/Functional/app/AppKernel.php

@@ -14,6 +14,7 @@ namespace Symfony\Bundle\FrameworkBundle\Tests\Functional\app;
 use Psr\Log\NullLogger;
 use Symfony\Component\Config\Loader\LoaderInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\Filesystem\Filesystem;
 use Symfony\Component\HttpKernel\Kernel;
 
@@ -96,4 +97,13 @@ class AppKernel extends Kernel
 
         return $parameters;
     }
+
+    public function getContainer(): ContainerInterface
+    {
+        if (!$this->booted) {
+            throw new \LogicException('Cannot access the container on a non-booted kernel. Did you forget to boot it?');
+        }
+
+        return parent::getContainer();
+    }
 }

src/Symfony/Bundle/SecurityBundle/Tests/Functional/app/AppKernel.php

@@ -12,6 +12,7 @@
 namespace Symfony\Bundle\SecurityBundle\Tests\Functional\app;
 
 use Symfony\Component\Config\Loader\LoaderInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\Filesystem\Filesystem;
 use Symfony\Component\HttpKernel\Kernel;
 
@@ -98,4 +99,13 @@ class AppKernel extends Kernel
 
         return $parameters;
     }
+
+    public function getContainer(): ContainerInterface
+    {
+        if (!$this->booted) {
+            throw new \LogicException('Cannot access the container on a non-booted kernel. Did you forget to boot it?');
+        }
+
+        return parent::getContainer();
+    }
 }

src/Symfony/Component/HttpKernel/CHANGELOG.md

@@ -14,6 +14,7 @@ CHANGELOG
    so you likely do not use those in any app based on the SF Standard or Flex edition.
  * Marked all dispatched event classes as `@final`
  * Added `ErrorController` to enable the preview and error rendering mechanism
+ * Getting the container from a non-booted kernel is deprecated.
 
 4.3.0
 -----

src/Symfony/Component/HttpKernel/Kernel.php

@@ -380,6 +380,10 @@ abstract class Kernel implements KernelInterface, RebootableInterface, Terminabl
      */
     public function getContainer()
     {
+        if (!$this->booted) {
+            @trigger_error('Getting the container from a non-booted kernel is deprecated since Symfony 4.4.', E_USER_DEPRECATED);
+        }
+
         return $this->container;
     }
 

src/Symfony/Component/HttpKernel/KernelInterface.php

@@ -124,7 +124,7 @@ interface KernelInterface extends HttpKernelInterface
     /**
      * Gets the current container.
      *
-     * @return ContainerInterface|null A ContainerInterface instance or null when the Kernel is shutdown
+     * @return ContainerInterface
      */
     public function getContainer();
 

src/Symfony/Component/HttpKernel/Tests/KernelTest.php

@@ -46,6 +46,17 @@ class KernelTest extends TestCase
         $this->assertEquals($debug, $kernel->isDebug());
         $this->assertFalse($kernel->isBooted());
         $this->assertLessThanOrEqual(microtime(true), $kernel->getStartTime());
+    }
+
+    /**
+     * @group legacy
+     * @expectedDeprecation Getting the container from a non-booted kernel is deprecated since Symfony 4.4.
+     */
+    public function testGetContainerForANonBootedKernel()
+    {
+        $kernel = new KernelForTest('test_env', true);
+
+        $this->assertFalse($kernel->isBooted());
         $this->assertNull($kernel->getContainer());
     }
 
@@ -61,7 +72,6 @@ class KernelTest extends TestCase
         $this->assertEquals($debug, $clone->isDebug());
         $this->assertFalse($clone->isBooted());
         $this->assertLessThanOrEqual(microtime(true), $clone->getStartTime());
-        $this->assertNull($clone->getContainer());
     }
 
     public function testClassNameValidityGetter()
@@ -486,6 +496,18 @@ EOF;
         $kernel->terminate(Request::create('/'), new Response());
     }
 
+    /**
+     * @group legacy
+     * @expectedDeprecation Getting the container from a non-booted kernel is deprecated since Symfony 4.4.
+     */
+    public function testDeprecatedNullKernel()
+    {
+        $kernel = $this->getKernel();
+        $kernel->shutdown();
+
+        $this->assertNull($kernel->getContainer());
+    }
+
     public function testTerminateDelegatesTerminationOnlyForTerminableInterface()
     {
         // does not implement TerminableInterface