Only emit Test\AssertionSucceeded and Test\AssertionFailed events when they have subscribers

Author: sebastianbergmann

src/Event/Dispatcher/DeferringDispatcher.php

@@ -34,6 +34,14 @@ public function registerSubscriber(Subscriber $subscriber): void
         $this->dispatcher->registerSubscriber($subscriber);
     }
 
+    /**
+     * @psalm-param class-string $className
+     */
+    public function hasSubscriberFor(string $className): bool
+    {
+        return $this->dispatcher->hasSubscriberFor($className);
+    }
+
     public function dispatch(Event $event): void
     {
         if ($this->recording) {

src/Event/Dispatcher/DirectDispatcher.php

@@ -66,6 +66,22 @@ public function registerSubscriber(Subscriber $subscriber): void
         $this->subscribers[$eventClassName][] = $subscriber;
     }
 
+    /**
+     * @psalm-param class-string $className
+     */
+    public function hasSubscriberFor(string $className): bool
+    {
+        if ($this->tracers !== []) {
+            return true;
+        }
+
+        if (isset($this->subscribers[$className])) {
+            return true;
+        }
+
+        return false;
+    }
+
     /**
      * @throws UnknownEventTypeException
      */

src/Event/Dispatcher/SubscribableDispatcher.php

@@ -20,4 +20,9 @@ interface SubscribableDispatcher extends Dispatcher
     public function registerSubscriber(Subscriber $subscriber): void;
 
     public function registerTracer(Tracer\Tracer $tracer): void;
+
+    /**
+     * @psalm-param class-string $className
+     */
+    public function hasSubscriberFor(string $className): bool;
 }

src/Event/Emitter/DispatchingEmitter.php

@@ -400,6 +400,10 @@ public function testRegisteredComparator(string $className): void
      */
     public function testAssertionSucceeded(mixed $value, Constraint\Constraint $constraint, string $message): void
     {
+        if (!$this->hasSubscriberFor(Test\AssertionSucceeded::class)) {
+            return;
+        }
+
         $this->dispatcher->dispatch(
             new Test\AssertionSucceeded(
                 $this->telemetryInfo(),
@@ -417,6 +421,10 @@ public function testAssertionSucceeded(mixed $value, Constraint\Constraint $cons
      */
     public function testAssertionFailed(mixed $value, Constraint\Constraint $constraint, string $message): void
     {
+        if (!$this->hasSubscriberFor(Test\AssertionFailed::class)) {
+            return;
+        }
+
         $this->dispatcher->dispatch(
             new Test\AssertionFailed(
                 $this->telemetryInfo(),
@@ -1048,4 +1056,13 @@ private function telemetryInfo(): Telemetry\Info
 
         return $info;
     }
+
+    private function hasSubscriberFor(string $className): bool
+    {
+        if (!$this->dispatcher instanceof SubscribableDispatcher) {
+            return true;
+        }
+
+        return $this->dispatcher->hasSubscriberFor($className);
+    }
 }