@@ -110,6 +110,7 @@
  * ## Parts
  *
  * * `services`: Includes methods related to the Symfony dependency injection container (DIC):
+ *     * grabContainer
  *     * grabService
  *     * mockService
  *     * persistService
@@ -286,6 +287,11 @@ protected function onReconfigure(array $settings = []): void
      * persistent: that preserves the open test transaction across reboots while
      * the freshly rebuilt EntityManager runs on top of it.
      *
+     * If the resolved EntityManager was closed by a failed flush, it is reopened through
+     * Doctrine's registry before being handed out, so one broken write does not cascade
+     * through the rest of the test. Nothing is cached: the container stays the single
+     * source of truth.
+     *
      * @see https://github.com/Codeception/module-symfony/issues/34
      */
     public function _getEntityManager(): EntityManagerInterface
@@ -300,9 +306,10 @@ public function _getEntityManager(): EntityManagerInterface
             }
         }
 
-        $em = $this->getService($emService);
-        if (!$em instanceof EntityManagerInterface) {
-            Assert::fail(sprintf('Service "%s" is not an instance of EntityManagerInterface.', $emService));
+        $em = $this->resolveEntityManager($emService);
+
+        if (!$em->isOpen() && $this->resetManagerThroughRegistry(null)) {
+            $em = $this->resolveEntityManager($emService);
         }
 
         return $em;
 
@@ -4,10 +4,13 @@
 
 namespace Codeception\Module\Symfony;
 
+use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\EntityRepository;
 use Doctrine\ORM\Tools\SchemaValidator;
+use Doctrine\Persistence\ManagerRegistry;
 use PHPUnit\Framework\Assert;
 use Symfony\Bridge\Doctrine\DataCollector\DoctrineDataCollector;
+use Throwable;
 
 use function array_count_values;
 use function array_filter;
@@ -53,6 +56,28 @@ public function dontSeeDuplicateQueries(): void
         );
     }
 
+    /**
+     * Returns the Doctrine EntityManager the module is configured to use:
+     * the `em_service` option, `doctrine.orm.entity_manager` by default.
+     *
+     * The manager is resolved from the container on every call, so it always belongs to the
+     * kernel that is currently booted. Don't keep it in a property across requests:
+     * [`amOnPage()`](#amOnPage) and friends reboot the kernel, which builds a new manager.
+     *
+     * To reach a manager other than the configured one, grab it by service id:
+     * `$I->grabService('doctrine.orm.other_entity_manager')`.
+     *
+     * ```php
+     * <?php
+     * $em = $I->grabEntityManager();
+     * $user = $em->getRepository(User::class)->findOneBy(['email' => 'john_doe@gmail.com']);
+     * ```
+     */
+    public function grabEntityManager(): EntityManagerInterface
+    {
+        return $this->_getEntityManager();
+    }
+
     /**
      * Returns the number of rows that match the given criteria for the
      * specified Doctrine entity.
@@ -135,6 +160,53 @@ public function seeNumQueriesIsLessThan(int $expectedCount): void
         );
     }
 
+    /**
+     * Resets the Doctrine EntityManager.
+     *
+     * Doctrine closes the EntityManager as soon as an exception escapes a `flush()`:
+     * a unique constraint violation, a deadlock, a failed transaction. Every write after
+     * that throws `EntityManagerClosed`, which usually surfaces as an unrelated failure
+     * further down the test. Call this after deliberately provoking such an error to carry
+     * on with a healthy manager.
+     *
+     * If the manager is still open it is only cleared, detaching every managed entity,
+     * which is handy to prove that the next read really hits the database.
+     * The open test transaction is preserved either way: the manager is rebuilt,
+     * the DBAL connection underneath it is not.
+     *
+     * ```php
+     * <?php
+     * $I->amOnPage('/register');
+     * $I->resetDoctrineManager();
+     * $I->seeNumRecords(1, User::class);
+     * ```
+     *
+     * @param non-empty-string|null $name Manager name as registered in Doctrine's registry,
+     *                                    `null` for the default one.
+     */
+    public function resetDoctrineManager(?string $name = null): void
+    {
+        $em = $this->_getEntityManager();
+
+        if ($em->isOpen()) {
+            $em->clear();
+
+            return;
+        }
+
+        if (!$this->resetManagerThroughRegistry($name) || !$this->_getEntityManager()->isOpen()) {
+            $this->rebootClientKernel();
+        }
+
+        if (!$this->_getEntityManager()->isOpen()) {
+            Assert::fail(
+                "The Doctrine EntityManager is still closed after resetting it.\n"
+                . "Check that the module's 'em_service' option points at your entity manager "
+                . 'and that the container can rebuild it.'
+            );
+        }
+    }
+
     /**
      * Asserts that a given number of records exists for the entity.
      * 'id' is the default search parameter.
@@ -244,4 +316,55 @@ private function isTransactionStatement(string $sql): bool
     {
         return preg_match('/^\s*("|`)?(START\s+TRANSACTION|BEGIN|COMMIT|ROLLBACK|SAVEPOINT|RELEASE\s+SAVEPOINT)\b/i', $sql) === 1;
     }
+
+    /**
+     * Rebuilds the manager through Doctrine's registry, which swaps the lazy service in
+     * place: everything already holding the manager, the application and the Doctrine
+     * module included, sees the reopened one.
+     *
+     * Returns false when the app has no registry, or when the manager service is not lazy
+     * and therefore cannot be reset that way.
+     *
+     * @param non-empty-string|null $name
+     */
+    private function resetManagerThroughRegistry(?string $name): bool
+    {
+        if (!interface_exists(ManagerRegistry::class)) {
+            return false;
+        }
+
+        $registry = $this->getService('doctrine');
+        if (!$registry instanceof ManagerRegistry) {
+            return false;
+        }
+
+        try {
+            $registry->resetManager($name);
+        } catch (Throwable) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Resolves the configured entity manager service, failing with a hint
+     * instead of a type error when Doctrine isn't wired up.
+     *
+     * @param non-empty-string $serviceId
+     */
+    private function resolveEntityManager(string $serviceId): EntityManagerInterface
+    {
+        $em = $this->getService($serviceId);
+
+        if (!$em instanceof EntityManagerInterface) {
+            Assert::fail(sprintf(
+                "The '%s' service is not a Doctrine EntityManager.\n"
+                . "Install and enable doctrine/doctrine-bundle, or point the module's 'em_service' option at your entity manager.",
+                $serviceId
+            ));
+        }
+
+        return $em;
+    }
 }
@@ -6,6 +6,7 @@
 
 use InvalidArgumentException;
 use PHPUnit\Framework\Assert;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 trait ServicesAssertionsTrait
 {
@@ -23,6 +24,30 @@ trait ServicesAssertionsTrait
      */
     protected array $permanentServices = [];
 
+    /**
+     * Returns the Symfony dependency injection container (DIC).
+     *
+     * In the "test" environment this is Symfony's special `test.service_container`,
+     * so private services are reachable too, unlike
+     * `$I->grabService('kernel')->getContainer()`, which only ever exposes the public ones.
+     *
+     * The container belongs to the kernel that is currently booted, so grab it again after
+     * a request or a [`rebootClientKernel()`](#rebootClientKernel) instead of keeping it
+     * in a property.
+     *
+     * ```php
+     * <?php
+     * $container = $I->grabContainer();
+     * $isDebug = $container->getParameter('kernel.debug');
+     * ```
+     *
+     * @part services
+     */
+    public function grabContainer(): ContainerInterface
+    {
+        return $this->_getContainer();
+    }
+
     /**
      * Grabs a service from the Symfony dependency injection container (DIC).
      * In the "test" environment, Symfony uses a special `test.service_container`.
 
@@ -6,6 +6,7 @@
 
 use Codeception\Module\Symfony\DoctrineAssertionsTrait;
 use PHPUnit\Framework\AssertionFailedError;
+use Tests\App\Doctrine\TestManagerRegistry;
 use Tests\App\Entity\User;
 use Tests\App\Repository\UserRepository;
 use Tests\App\Repository\UserRepositoryInterface;
@@ -30,6 +31,11 @@ public function testDontSeeDuplicateQueriesDetectsDuplicates(): void
         $this->dontSeeDuplicateQueries();
     }
 
+    public function testGrabEntityManager(): void
+    {
+        $this->assertSame($this->_getEntityManager(), $this->grabEntityManager());
+    }
+
     public function testGrabNumRecords(): void
     {
         $this->assertSame(1, $this->grabNumRecords(User::class));
@@ -50,6 +56,24 @@ public function testSeeNumQueriesIsLessThan(): void
         $this->seeNumQueriesIsLessThan(3);
     }
 
+    public function testResetDoctrineManager(): void
+    {
+        $em = $this->grabEntityManager();
+        $user = $em->getRepository(User::class)->findOneBy(['email' => 'john_doe@gmail.com']);
+        $this->assertTrue($em->contains($user));
+
+        $this->resetDoctrineManager();
+        $this->assertFalse($this->grabEntityManager()->contains($user));
+
+        /** @var TestManagerRegistry $registry */
+        $registry = $this->grabService('doctrine');
+        $this->grabEntityManager()->close();
+        $this->resetDoctrineManager();
+
+        $this->assertSame(1, $registry->resets);
+        $this->assertTrue($this->grabEntityManager()->isOpen());
+    }
+
     public function testSeeNumRecords(): void
     {
         $this->seeNumRecords(1, User::class);
 
@@ -13,6 +13,14 @@ final class ServicesAssertionsTest extends CodeceptTestCase
 {
     use ServicesAssertionsTrait;
 
+    public function testGrabContainer(): void
+    {
+        $container = $this->grabContainer();
+
+        $this->assertSame($this->_getContainer(), $container);
+        $this->assertTrue($container->hasParameter('app.param'));
+    }
+
     public function testGrabService(): void
     {
         $this->assertIsObject($this->grabService('security.helper'));
 
@@ -6,6 +6,7 @@
 
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\DriverManager;
+use Doctrine\ORM\Configuration;
 use Doctrine\ORM\EntityManager;
 use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\ORMSetup;
@@ -21,10 +22,40 @@ public static function createConnection(): Connection
 
     public static function createEntityManager(): EntityManagerInterface
     {
-        if (self::$entityManager !== null && self::$entityManager->isOpen()) {
+        if (self::$entityManager !== null) {
             return self::$entityManager;
         }
 
+        $connection = DriverManager::getConnection(['driver' => 'pdo_sqlite', 'memory' => true]);
+
+        return self::$entityManager = self::makeEntityManager($connection);
+    }
+
+    /**
+     * Rebuilds the manager on the same connection, mirroring what
+     * ManagerRegistry::resetManager() does for a lazy service. Reusing the connection
+     * matters here: the fixture database is in-memory, so reconnecting would lose the schema.
+     */
+    public static function resetEntityManager(): void
+    {
+        $connection = self::createEntityManager()->getConnection();
+
+        self::$entityManager = self::makeEntityManager($connection);
+    }
+
+    private static function makeEntityManager(Connection $connection): EntityManagerInterface
+    {
+        $config = self::createConfiguration();
+
+        if (method_exists(EntityManager::class, 'create')) {
+            return EntityManager::create($connection, $config);
+        }
+
+        return new EntityManager($connection, $config);
+    }
+
+    private static function createConfiguration(): Configuration
+    {
         $entityDir = dirname(__DIR__) . '/Entity';
 
         if (method_exists(ORMSetup::class, 'createAttributeMetadataConfig')) {
@@ -46,14 +77,6 @@ public static function createEntityManager(): EntityManagerInterface
             $config->enableNativeLazyObjects(true);
         }
 
-        $connection = DriverManager::getConnection(['driver' => 'pdo_sqlite', 'memory' => true]);
-
-        if (method_exists(EntityManager::class, 'create')) {
-            self::$entityManager = EntityManager::create($connection, $config);
-        } else {
-            self::$entityManager = new EntityManager($connection, $config);
-        }
-
-        return self::$entityManager;
+        return $config;
     }
 }
Original file line number	Diff line number	Diff line change
`@@ -13,6 +13,14 @@ final class ServicesAssertionsTest extends CodeceptTestCase`
`13`	`13`	`{`
`14`	`14`	`use ServicesAssertionsTrait;`
`15`	`15`
	`16`	`+ public function testGrabContainer(): void`
	`17`	`+ {`
	`18`	`+ $container = $this->grabContainer();`
	`19`	`+`
	`20`	`+ $this->assertSame($this->_getContainer(), $container);`
	`21`	`+ $this->assertTrue($container->hasParameter('app.param'));`
	`22`	`+ }`
	`23`	`+`
`16`	`24`	`public function testGrabService(): void`
`17`	`25`	`{`
`18`	`26`	`$this->assertIsObject($this->grabService('security.helper'));`