Improve test

impl/maven-cli/src/test/java/org/apache/maven/cling/transfer/SimplexTransferListenerTest.java

@@ -33,7 +33,7 @@
 
 class SimplexTransferListenerTest {
     @Test
-    void cancellation() throws InterruptedException {
+    void cancellation() {
         TransferListener delegate = new TransferListener() {
             @Override
             public void transferInitiated(TransferEvent event) throws TransferCancelledException {
@@ -66,12 +66,12 @@ public void transferFailed(TransferEvent event) {}
 
         TransferResource resource =
                 new TransferResource(null, null, "http://maven.org/test/test-resource", new File("file"), null);
-        DefaultRepositorySystemSession session = new DefaultRepositorySystemSession(h -> false); // no close handle
+        DefaultRepositorySystemSession session = new DefaultRepositorySystemSession(h -> false);
 
-        // for technical reasons we cannot throw here, even if delegate does cancel transfer
+        // Send initiated event and make it the "last" event to force blocking
         listener.transferInitiated(event(session, resource, TransferEvent.EventType.INITIATED));
-
-        Thread.sleep(500); // to make sure queue is processed, cancellation applied
+        // Use transferFailed as a sentinel to ensure the previous event was processed
+        listener.transferFailed(event(session, resource, TransferEvent.EventType.FAILED));
 
         // subsequent call will cancel
         assertThrows(
@@ -80,7 +80,7 @@ public void transferFailed(TransferEvent event) {}
     }
 
     @Test
-    void handlesAbsentTransferSource() throws InterruptedException, TransferCancelledException {
+    void handlesAbsentTransferSource() throws TransferCancelledException {
         TransferResource resource = new TransferResource(null, null, "http://maven.org/test/test-resource", null, null);
 
         RepositorySystemSession session = Mockito.mock(RepositorySystemSession.class);
@@ -95,10 +95,9 @@ void handlesAbsentTransferSource() throws InterruptedException, TransferCancelle
         listener.transferInitiated(transferInitiatedEvent);
         listener.transferStarted(transferStartedEvent);
         listener.transferProgressed(transferProgressedEvent);
+        // The succeeded event will be the last one and will block until processed
         listener.transferSucceeded(transferSucceededEvent);
 
-        Thread.sleep(500); // to make sure queue is processed, cancellation applied
-
         Mockito.verify(delegate).transferInitiated(transferInitiatedEvent);
         Mockito.verify(delegate).transferStarted(transferStartedEvent);
         Mockito.verify(delegate).transferProgressed(transferProgressedEvent);