diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index b231c66..f363898 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -43,5 +43,8 @@ jobs:
     - name: PHPStan
       run: bin/phpstan
 
+    - name: Composer validate
+      run: composer validate
+
  #   - name: Infection
 #      run: bin/infection --formatter=progress
diff --git a/composer.json b/composer.json
index 17cc4a4..ea8813b 100644
--- a/composer.json
+++ b/composer.json
@@ -31,7 +31,7 @@
         "infection/infection": "~0.13",
         "phpstan/phpstan": "^2.0",
         "phpstan/phpstan-phpunit": "^2.0",
-        "phpunit/phpunit": "^8.5",
+        "phpunit/phpunit": "^10.0|^11.0|^12.0",
         "squizlabs/php_codesniffer": "^3.2",
         "symfony/cache": "^4.0|^5.0|^6.0"
     },
diff --git a/examples/ContextUsingCustomMetadataTest.php b/examples/ContextUsingCustomMetadataTest.php
index 6b6e2d8..cd15ff1 100644
--- a/examples/ContextUsingCustomMetadataTest.php
+++ b/examples/ContextUsingCustomMetadataTest.php
@@ -64,7 +64,7 @@ public function test_it_should_allow_to_transit_from_pending_to_archived(): void
         $this->assertTrue($context->state->isInState('archived'));
     }
 
-    public function test_it_should_allow_to_transit_from_approved_to_published(): ContextStub
+    public function test_it_should_allow_to_transit_from_approved_to_published(): void
     {
         $context = new ContextStub();
         $context->approve();
@@ -73,8 +73,6 @@ public function test_it_should_allow_to_transit_from_approved_to_published(): Co
         $context->publish();
 
         $this->assertTrue($context->state->isInState('published'));
-
-        return $context;
     }
 
     public function test_it_should_allow_to_transit_from_approved_to_archived(): void
@@ -100,7 +98,7 @@ public function test_it_should_allow_to_transit_from_published_to_approved(): vo
         $this->assertTrue($context->state->isInState('approved'));
     }
 
-    public function test_it_should_allow_to_transit_from_published_to_archived(): ContextStub
+    public function test_it_should_allow_to_transit_from_published_to_archived(): void
     {
         $context = new ContextStub();
         $context->approve();
@@ -110,8 +108,6 @@ public function test_it_should_allow_to_transit_from_published_to_archived(): Co
         $context->archive();
 
         $this->assertTrue($context->state->isInState('archived'));
-
-        return $context;
     }
 
     public function test_it_should_allow_to_transit_from_archived_to_pending(): void
@@ -125,7 +121,7 @@ public function test_it_should_allow_to_transit_from_archived_to_pending(): void
         $this->assertTrue($context->state->isInState('pending'));
     }
 
-    public function test_it_should_allow_to_transit_from_archived_to_approved(): ContextStub
+    public function test_it_should_allow_to_transit_from_archived_to_approved(): void
     {
         $context = new ContextStub();
         $context->discard();
@@ -134,8 +130,6 @@ public function test_it_should_allow_to_transit_from_archived_to_approved(): Con
         $context->unArchive();
 
         $this->assertTrue($context->state->isInState('approved'));
-
-        return $context;
     }
 
     public function test_attributes_of_pending(): void
@@ -146,34 +140,35 @@ public function test_attributes_of_pending(): void
         $this->assertFalse($context->isVisible());
     }
 
-    /**
-     * @param ContextStub $context
-     * @depends test_it_should_allow_to_transit_from_archived_to_approved
-     */
-    public function test_attributes_of_approved(ContextStub $context): void
+    public function test_attributes_of_approved(): void
     {
+        $context = new ContextStub();
+        $context->discard();
+        $context->unArchive();
+
         $this->assertTrue($context->state->isInState('approved'));
         $this->assertTrue($context->isDraft());
         $this->assertFalse($context->isVisible());
     }
 
-    /**
-     * @param ContextStub $context
-     * @depends test_it_should_allow_to_transit_from_approved_to_published
-     */
-    public function test_attributes_of_published(ContextStub $context): void
+    public function test_attributes_of_published(): void
     {
+        $context = new ContextStub();
+        $context->approve();
+        $context->publish();
+
         $this->assertTrue($context->state->isInState('published'));
         $this->assertFalse($context->isDraft());
         $this->assertTrue($context->isVisible());
     }
 
-    /**
-     * @param ContextStub $context
-     * @depends test_it_should_allow_to_transit_from_published_to_archived
-     */
-    public function test_attributes_of_archived(ContextStub $context): void
+    public function test_attributes_of_archived(): void
     {
+        $context = new ContextStub();
+        $context->approve();
+        $context->publish();
+        $context->archive();
+
         $this->assertTrue($context->state->isInState('archived'));
         $this->assertFalse($context->isDraft());
         $this->assertFalse($context->isVisible());
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index d57baea..0b8da95 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -2,18 +2,13 @@
 
 <!-- http://www.phpunit.de/manual/current/en/appendixes.configuration.html -->
 <phpunit
-        backupGlobals = "false"
-        backupStaticAttributes = "false"
-        colors = "true"
-        convertErrorsToExceptions = "true"
-        convertNoticesToExceptions = "true"
-        convertWarningsToExceptions = "true"
-        convertDeprecationsToExceptions = "true"
-        beStrictAboutOutputDuringTests = "true"
-        beStrictAboutTestsThatDoNotTestAnything="true"
-        failOnRisky="true"
-        failOnWarning="true"
-        bootstrap = "vendor/autoload.php" >
+        backupGlobals="false"
+        backupStaticProperties="false"
+        colors="true"
+        beStrictAboutOutputDuringTests="true"
+        failOnAllIssues="true"
+        bootstrap="vendor/autoload.php"
+>
 
     <testsuites>
         <testsuite name="main">
@@ -25,9 +20,9 @@
         </testsuite>
     </testsuites>
 
-    <filter>
-        <whitelist>
-            <directory>src</directory>
-        </whitelist>
-    </filter>
+    <source>
+        <include>
+            <directory suffix=".php">src</directory>
+        </include>
+    </source>
 </phpunit>
diff --git a/src/StateMachine.php b/src/StateMachine.php
index 448e388..16748c3 100644
--- a/src/StateMachine.php
+++ b/src/StateMachine.php
@@ -7,6 +7,7 @@
 
 namespace Star\Component\State;
 
+use Closure;
 use Star\Component\State\Callbacks\AlwaysThrowExceptionOnFailure;
 use Star\Component\State\Callbacks\TransitionCallback;
 use Star\Component\State\Event\StateEventStore;
@@ -39,8 +40,11 @@ public function __construct(
      * @throws InvalidStateTransitionException
      * @throws NotFoundException
      */
-    public function transit(string $transitionName, $context, TransitionCallback $callback = null): string
-    {
+    public function transit(
+        string $transitionName,
+        mixed $context,
+        ?TransitionCallback $callback = null
+    ): string {
         if (!$callback) {
             $callback = new AlwaysThrowExceptionOnFailure();
         }
@@ -101,7 +105,7 @@ public function hasAttribute(string $attribute): bool
         return $this->states->hasAttribute($this->currentState, $attribute);
     }
 
-    public function addListener(string $event, \Closure $listener): void
+    public function addListener(string $event, Closure $listener): void
     {
         $this->listeners->addListener($event, $listener);
     }
diff --git a/src/StateMetadata.php b/src/StateMetadata.php
index edc446a..b3310c5 100644
--- a/src/StateMetadata.php
+++ b/src/StateMetadata.php
@@ -39,8 +39,11 @@ private function getMachine(): StateMachine
      *
      * @return static
      */
-    final public function transit(string $name, $context, TransitionCallback $callback = null): StateMetadata
-    {
+    final public function transit(
+        string $name,
+        $context,
+        ?TransitionCallback $callback = null
+    ): StateMetadata {
         $this->current = $this->getMachine()->transit($name, $context, $callback);
 
         return $this;
diff --git a/tests/StateMachineTest.php b/tests/StateMachineTest.php
index bcecc9a..9b4b021 100644
--- a/tests/StateMachineTest.php
+++ b/tests/StateMachineTest.php
@@ -7,30 +7,29 @@
 
 namespace Star\Component\State;
 
-use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Star\Component\State\Event\StateEventStore;
 use Star\Component\State\Event\TransitionWasFailed;
 use Star\Component\State\Event\TransitionWasSuccessful;
 use Star\Component\State\Event\TransitionWasRequested;
+use Star\Component\State\Stub\EventRegistrySpy;
 use Star\Component\State\Transitions\OneToOneTransition;
+use stdClass;
+use Throwable;
 
 final class StateMachineTest extends TestCase
 {
     private TransitionRegistry $registry;
     private StateMachine $machine;
     private TestContext $context;
-    /**
-     * @var MockObject|EventRegistry
-     */
-    private $listeners;
+    private EventRegistrySpy $events;
 
     public function setUp(): void
     {
-        $this->listeners = $this->createMock(EventRegistry::class);
+        $this->events = new EventRegistrySpy();
         $this->context = new TestContext();
         $this->registry = new TransitionRegistry();
-        $this->machine = new StateMachine('current', $this->registry, $this->listeners);
+        $this->machine = new StateMachine('current', $this->registry, $this->events);
     }
 
     public function test_it_should_not_allow_to_transition_to_a_not_configured_transition(): void
@@ -52,30 +51,22 @@ public function test_it_should_transition_from_one_state_to_the_other(): void
 
     public function test_it_should_trigger_an_event_before_any_transition(): void
     {
-        $this->listeners
-            ->expects($this->at(0))
-            ->method('dispatch')
-            ->with(
-                StateEventStore::BEFORE_TRANSITION,
-                $this->isInstanceOf(TransitionWasRequested::class)
-            );
-
         $this->registry->addTransition(new OneToOneTransition('name', 'current', 'next'));
         $this->machine->transit('name', $this->context);
+        $name = StateEventStore::BEFORE_TRANSITION;
+        $events = $this->events->getDispatchedEvents($name);
+        self::assertCount(1, $events);
+        self::assertContainsOnlyInstancesOf(TransitionWasRequested::class, $events);
     }
 
     public function test_it_should_trigger_an_event_after_any_transition(): void
     {
-        $this->listeners
-            ->expects($this->at(1))
-            ->method('dispatch')
-            ->with(
-                StateEventStore::AFTER_TRANSITION,
-                $this->isInstanceOf(TransitionWasSuccessful::class)
-            );
-
         $this->registry->addTransition(new OneToOneTransition('name', 'current', 'next'));
         $this->machine->transit('name', $this->context);
+        $name = StateEventStore::AFTER_TRANSITION;
+        $events = $this->events->getDispatchedEvents($name);
+        self::assertCount(1, $events);
+        self::assertContainsOnlyInstancesOf(TransitionWasSuccessful::class, $events);
     }
 
     public function test_it_should_throw_exception_with_class_context_when_transition_not_allowed(): void
@@ -87,7 +78,7 @@ public function test_it_should_throw_exception_with_class_context_when_transitio
         $this->expectExceptionMessage(
             "The transition 't' is not allowed when context 'stdClass' is in state 'current'."
         );
-        $this->machine->transit('t', new \stdClass);
+        $this->machine->transit('t', new stdClass);
     }
 
     public function test_it_should_throw_exception_with_context_as_string_when_transition_not_allowed(): void
@@ -112,7 +103,7 @@ public function test_state_can_have_attribute(): void
     public function test_it_should_visit_the_transitions(): void
     {
         $registry = $this->createMock(StateRegistry::class);
-        $machine = new StateMachine('', $registry, $this->listeners);
+        $machine = new StateMachine('', $registry, $this->events);
         $visitor = $this->createMock(TransitionVisitor::class);
 
         $registry
@@ -131,20 +122,18 @@ public function test_it_should_throw_exception_when_state_do_not_exists(): void
 
     public function test_it_should_dispatch_an_event_before_a_transition_has_failed(): void
     {
-        $this->listeners
-            ->expects($this->at(1))
-            ->method('dispatch')
-            ->with(
-                StateEventStore::FAILURE_TRANSITION,
-                $this->isInstanceOf(TransitionWasFailed::class)
-            );
-
         $this->registry->addTransition(new OneToOneTransition('t', 'from', 'to'));
         try {
             $this->machine->transit('t', 'context');
             $this->fail('An exception should have been thrown');
-        } catch (InvalidStateTransitionException $exception) {
+        } catch (Throwable $exception) {
             // silence it
+            self::assertInstanceOf(InvalidStateTransitionException::class, $exception);
         }
+
+        $name = StateEventStore::FAILURE_TRANSITION;
+        $events = $this->events->getDispatchedEvents($name);
+        self::assertCount(1, $events);
+        self::assertContainsOnlyInstancesOf(TransitionWasFailed::class, $events);
     }
 }
diff --git a/tests/Stub/EventRegistrySpy.php b/tests/Stub/EventRegistrySpy.php
new file mode 100644
index 0000000..dae3c59
--- /dev/null
+++ b/tests/Stub/EventRegistrySpy.php
@@ -0,0 +1,45 @@
+<?php declare(strict_types=1);
+
+namespace Star\Component\State\Stub;
+
+use Star\Component\State\Event\StateEvent;
+use Star\Component\State\EventRegistry;
+
+final class EventRegistrySpy implements EventRegistry
+{
+    /**
+     * @var array<string, callable[]>
+     */
+    private array $listeners = [];
+
+    /**
+     * @var array<string, array<int, StateEvent>>
+     */
+    private array $dispatches = [];
+
+    public function dispatch(string $name, StateEvent $event): void
+    {
+        $this->dispatches[$name][] = $event;
+    }
+
+    public function addListener(string $event, callable $listener): void
+    {
+        $this->listeners[$event][] = $listener;
+    }
+
+    /**
+     * @return StateEvent[]
+     */
+    public function getDispatchedEvents(string $event): array
+    {
+        return $this->dispatches[$event] ?? [];
+    }
+
+    /**
+     * @return callable[]
+     */
+    public function getListenersOfEvent(string $event): array
+    {
+        return $this->listeners[$event] ?? [];
+    }
+}
diff --git a/tests/Stub/RegistrySpy.php b/tests/Stub/RegistryBuilderSpy.php
similarity index 95%
rename from tests/Stub/RegistrySpy.php
rename to tests/Stub/RegistryBuilderSpy.php
index a61b39e..c34d806 100644
--- a/tests/Stub/RegistrySpy.php
+++ b/tests/Stub/RegistryBuilderSpy.php
@@ -4,7 +4,7 @@
 
 use Star\Component\State\RegistryBuilder;
 
-final class RegistrySpy implements RegistryBuilder
+final class RegistryBuilderSpy implements RegistryBuilder
 {
     /**
      * @var array<string, array{
diff --git a/tests/TransitionRegistryTest.php b/tests/TransitionRegistryTest.php
index a13b563..b62a211 100644
--- a/tests/TransitionRegistryTest.php
+++ b/tests/TransitionRegistryTest.php
@@ -117,18 +117,34 @@ public function test_it_should_visit_the_transitions(): void
 
     public function test_it_should_visit_the_states(): void
     {
-        $visitor = $this->getMockBuilder(StateVisitor::class)->getMock();
-        $visitor
-            ->expects($this->at(0))
-            ->method('visitState')
-            ->with('from', ['attr']);
-        $visitor
-            ->expects($this->at(1))
-            ->method('visitState')
-            ->with('to', []);
+        $visitor = new class implements StateVisitor
+        {
+            /**
+             * @var array<string, array<int, string[]>>
+             */
+            public array $attributes = [];
+
+            public function visitState(string $name, array $attributes): void
+            {
+                $this->attributes[$name][] = $attributes;
+            }
+        };
         $this->registry->addTransition(new OneToOneTransition('t', 'from', 'to'));
         $this->registry->addAttribute('from', 'attr');
 
         $this->registry->acceptStateVisitor($visitor);
+        self::assertSame(
+            [
+                'from' => [
+                    0 => [
+                        0 => 'attr',
+                    ],
+                ],
+                'to' => [
+                    0 => [],
+                ],
+            ],
+            $visitor->attributes
+        );
     }
 }
diff --git a/tests/Transitions/ManyToOneTransitionTest.php b/tests/Transitions/ManyToOneTransitionTest.php
index 6dc7424..486ba79 100644
--- a/tests/Transitions/ManyToOneTransitionTest.php
+++ b/tests/Transitions/ManyToOneTransitionTest.php
@@ -3,7 +3,7 @@
 namespace Star\Component\State\Transitions;
 
 use PHPUnit\Framework\TestCase;
-use Star\Component\State\Stub\RegistrySpy;
+use Star\Component\State\Stub\RegistryBuilderSpy;
 
 final class ManyToOneTransitionTest extends TestCase
 {
@@ -21,7 +21,7 @@ public function test_it_should_have_a_name(): void
 
     public function test_it_should_register_the_from_and_to_states(): void
     {
-        $registry = new RegistrySpy();
+        $registry = new RegistryBuilderSpy();
 
         $this->transition->onRegister($registry);
 
diff --git a/tests/Transitions/OneToOneTransitionTest.php b/tests/Transitions/OneToOneTransitionTest.php
index 9111dbb..0226613 100644
--- a/tests/Transitions/OneToOneTransitionTest.php
+++ b/tests/Transitions/OneToOneTransitionTest.php
@@ -3,7 +3,7 @@
 namespace Star\Component\State\Transitions;
 
 use PHPUnit\Framework\TestCase;
-use Star\Component\State\Stub\RegistrySpy;
+use Star\Component\State\Stub\RegistryBuilderSpy;
 
 final class OneToOneTransitionTest extends TestCase
 {
@@ -21,7 +21,7 @@ public function test_it_should_have_a_name(): void
 
     public function test_it_should_register_the_from_and_to_states(): void
     {
-        $registry = new RegistrySpy();
+        $registry = new RegistryBuilderSpy();
 
         $this->transition->onRegister($registry);