Close Netty event loop group asynchronously in tests

Should speed up test suite a bit.

Author: acogoluegnes

src/test/java/com/rabbitmq/stream/impl/ShutdownListenerTest.java

@@ -67,6 +67,7 @@ void shutdownListenerShouldBeCalledOnServerClosing() throws Exception {
         .isNotNull()
         .isEqualTo(Client.ShutdownContext.ShutdownReason.SERVER_CLOSE);
     assertThat(client.isOpen()).isFalse();
+    client.close();
   }
 
   @Test
@@ -89,5 +90,6 @@ void shutdownListenerShouldBeCalledWhenConnectionIsKilled() throws Exception {
     assertThat(shutdownLatch.await(10, TimeUnit.SECONDS)).isTrue();
     assertThat(reason.get()).isNotNull().isEqualTo(Client.ShutdownContext.ShutdownReason.UNKNOWN);
     assertThat(client.isOpen()).isFalse();
+    client.close();
   }
 }

src/test/java/com/rabbitmq/stream/impl/TestUtils.java

@@ -57,6 +57,8 @@
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
@@ -75,12 +77,17 @@
 import org.junit.jupiter.api.extension.ExecutionCondition;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.ExtensionContext.Namespace;
+import org.junit.jupiter.api.extension.ExtensionContext.Store.CloseableResource;
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
+import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public final class TestUtils {
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(TestUtils.class);
+
   private TestUtils() {}
 
   public static Duration waitAtMost(CallableBooleanSupplier condition) throws Exception {
@@ -574,9 +581,39 @@ public void afterEach(ExtensionContext context) throws Exception {
     }
 
     @Override
-    public void afterAll(ExtensionContext context) throws Exception {
+    public void afterAll(ExtensionContext context) {
       EventLoopGroup eventLoopGroup = eventLoopGroup(context);
-      eventLoopGroup.shutdownGracefully(1, 10, SECONDS).get(10, SECONDS);
+      ExecutorServiceCloseableResourceWrapper wrapper =
+          context
+              .getRoot()
+              .getStore(Namespace.GLOBAL)
+              .getOrComputeIfAbsent(ExecutorServiceCloseableResourceWrapper.class);
+      wrapper.executorService.submit(
+          () -> {
+            try {
+              eventLoopGroup.shutdownGracefully(1, 10, SECONDS).get(10, SECONDS);
+            } catch (InterruptedException e) {
+              // happens at the end of the test suite
+              LOGGER.debug("Error while asynchronously closing Netty event loop group", e);
+              Thread.currentThread().interrupt();
+            } catch (Exception e) {
+              LOGGER.warn("Error while asynchronously closing Netty event loop group", e);
+            }
+          });
+    }
+
+    private static class ExecutorServiceCloseableResourceWrapper implements CloseableResource {
+
+      private final ExecutorService executorService;
+
+      private ExecutorServiceCloseableResourceWrapper() {
+        this.executorService = Executors.newCachedThreadPool();
+      }
+
+      @Override
+      public void close() throws Throwable {
+        this.executorService.shutdownNow();
+      }
     }
   }
 
@@ -700,6 +737,7 @@ public ConditionEvaluationResult evaluateExecutionCondition(ExtensionContext con
         Client client = new Client(new ClientParameters().eventLoopGroup(eventLoopGroup));
         String expectedVersion = annotation.value();
         String brokerVersion = client.brokerVersion();
+        client.close();
         if (atLeastVersion(expectedVersion, brokerVersion)) {
           return ConditionEvaluationResult.enabled(
               "Broker version requirement met, expected "