[LiveComponent] Add assert in test live component

src/LiveComponent/doc/index.rst

@@ -3781,6 +3781,12 @@ uses Symfony's test client to render and make requests to your components::
                 ->emit('increaseEvent', ['amount' => 2]) // emit a live event with arguments
             ;
 
+            // Assert that the event was emitted
+            $this->componentHasEmittedEvent($testComponent->render(), 'increaseEvent')
+                ->withData(['amount' => 2])
+                ->withDataSubset(['amount' => 2]) // test partial parameters
+            ;
+
             // set live props
             $testComponent
                 ->set('count', 99)

src/LiveComponent/src/Test/InteractsWithLiveComponents.php

@@ -44,4 +44,56 @@ protected function createLiveComponent(string $name, array $data = [], ?KernelBr
             self::getContainer()->get('router'),
         );
     }
+
+    /**
+     * @return object{withData: callable(array): void, withDataSubset: callable(array): object}
+     */
+    protected function assertComponentEmitEvent(TestLiveComponent $testLiveComponent, string $expectedEventName): object
+    {
+        $event = $testLiveComponent->getEmittedEvent($testLiveComponent->render(), $expectedEventName);
+
+        $this->assertNotNull($event, \sprintf('The component "%s" did not emit event "%s".', $testLiveComponent->getName(), $expectedEventName));
+
+        return new class($this, $event['event'], $event['data']) {
+            /**
+             * @param array<string, int|float|string|bool|null> $data
+             */
+            public function __construct(private KernelTestCase $parent, private readonly string $eventName, private readonly array $data)
+            {
+            }
+
+            /**
+             * @return self
+             */
+            public function withDataSubset(array $expectedEventData): object
+            {
+                foreach ($expectedEventData as $key => $value) {
+                    $this->parent->assertArrayHasKey($key, $this->data, \sprintf('The expected event "%s" data "%s" does not exists', $this->eventName, $key));
+                    $this->parent->assertSame(
+                        $value,
+                        $this->data[$key],
+                        \sprintf(
+                            'The expected event "%s" data "%s" expected "%s" but "%s" given',
+                            $this->eventName,
+                            $key,
+                            $value,
+                            $this->data[$key]
+                        )
+                    );
+                }
+
+                return $this;
+            }
+
+            public function withData(array $expectedEventData): void
+            {
+                $this->parent->assertEquals($expectedEventData, $this->data, \sprintf('The expected event "%s" data does not match.', $this->eventName));
+            }
+        };
+    }
+
+    protected function assertComponentNotEmitEvent(TestLiveComponent $testLiveComponent, string $eventName): void
+    {
+        $this->assertNull($testLiveComponent->getEmittedEvent($testLiveComponent->render(), $eventName), \sprintf('The component "%s" did not emit event "%s".', $testLiveComponent->getName(), $eventName));
+    }
 }

src/LiveComponent/src/Test/TestLiveComponent.php

@@ -229,4 +229,39 @@ private function flattenFormValues(array $values, string $prefix = ''): array
 
         return $result;
     }
+
+    /**
+     * @return ?array{data: array<string, int|float|string|bool|null>, event: non-empty-string}
+     */
+    public function getEmittedEvent(RenderedComponent $render, string $eventName): ?array
+    {
+        $events = $this->getEmittedEvents($render);
+
+        foreach ($events as $event) {
+            if ($event['event'] === $eventName) {
+                return $event;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @return array<array{data: array<string, int|float|string|bool|null>, event: non-empty-string}>
+     */
+    public function getEmittedEvents(RenderedComponent $render): array
+    {
+        $emit = $render->crawler()->filter('[data-live-name-value]')->attr('data-live-events-to-emit-value');
+
+        if (null === $emit) {
+            return [];
+        }
+
+        return json_decode($emit, associative: true, flags: \JSON_THROW_ON_ERROR);
+    }
+
+    public function getName(): string
+    {
+        return $this->metadata->getName();
+    }
 }

src/LiveComponent/tests/Fixtures/Component/ComponentWithEmit.php

@@ -29,7 +29,7 @@ final class ComponentWithEmit
     #[LiveAction]
     public function actionThatEmits(): void
     {
-        $this->emit('event1', ['foo' => 'bar']);
+        $this->emit('event1', ['foo' => 'bar', 'bar' => 'foo']);
         $this->events = $this->liveResponder->getEventsToEmit();
     }
 

src/LiveComponent/tests/Functional/LiveResponderTest.php

@@ -35,7 +35,7 @@ public function testComponentCanEmitEvents(): void
             ])
             ->assertSuccessful()
             ->assertSee('Event: event1')
-            ->assertSee('Data: {"foo":"bar"}');
+            ->assertSee('Data: {"foo":"bar","bar":"foo"}');
     }
 
     public function testComponentCanDispatchBrowserEvents(): void

src/LiveComponent/tests/Functional/Test/InteractsWithLiveComponentsTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\UX\LiveComponent\Tests\Functional\Test;
 
+use PHPUnit\Framework\AssertionFailedError;
 use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
 use Symfony\Component\Security\Core\Exception\AccessDeniedException;
 use Symfony\Component\Security\Core\User\InMemoryUser;
@@ -217,4 +218,75 @@ public function testSetLocaleRenderLocalizedComponent(): void
         $testComponent->setRouteLocale('de');
         $this->assertStringContainsString('Locale: de', $testComponent->render());
     }
+
+    public function testComponentEmitsExpectedEventData(): void
+    {
+        $testComponent = $this->createLiveComponent('component_with_emit');
+
+        $testComponent->call('actionThatEmits');
+
+        $this->assertComponentEmitEvent($testComponent, 'event1')->withData([
+            'foo' => 'bar',
+            'bar' => 'foo',
+        ]);
+    }
+
+    public function testComponentEmitsExpectedEventDataFails(): void
+    {
+        $testComponent = $this->createLiveComponent('component_with_emit');
+
+        $testComponent->call('actionThatEmits');
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('The expected event "event1" data does not match');
+        $this->assertComponentEmitEvent($testComponent, 'event1')->withData([
+            'foo' => 'bar',
+        ]);
+    }
+
+    public function testComponentEmitsExpectedPartialEventData(): void
+    {
+        $testComponent = $this->createLiveComponent('component_with_emit');
+
+        $testComponent->call('actionThatEmits');
+
+        $this->assertComponentEmitEvent($testComponent, 'event1')
+            ->withDataSubset(['foo' => 'bar'])
+            ->withDataSubset(['bar' => 'foo'])
+        ;
+    }
+
+    public function testComponentDoesNotEmitUnexpectedEvent(): void
+    {
+        $testComponent = $this->createLiveComponent('component_with_emit');
+
+        $testComponent->call('actionThatEmits');
+
+        $this->assertComponentNotEmitEvent($testComponent, 'event2');
+    }
+
+    public function testComponentDoesNotEmitUnexpectedEventFails(): void
+    {
+        $testComponent = $this->createLiveComponent('component_with_emit');
+
+        $testComponent->call('actionThatEmits');
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('The component "component_with_emit" did not emit event "event1".');
+        $this->assertComponentNotEmitEvent($testComponent, 'event1');
+    }
+
+    public function testComponentEmitsEventWithIncorrectDataFails(): void
+    {
+        $testComponent = $this->createLiveComponent('component_with_emit');
+
+        $testComponent->call('actionThatEmits');
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('The expected event "event1" data does not match.');
+        $this->assertComponentEmitEvent($testComponent, 'event1')->withData([
+            'foo' => 'bar',
+            'foo2' => 'bar2',
+        ]);
+    }
 }