Expose failing test in GenericMessagingTemplateTests

Assertions made in callbacks invoked on separate thread were not
reaching the test framework. This fix ensures failures are detected
and cause tests to fail.

spring-messaging/src/test/java/org/springframework/messaging/core/GenericMessagingTemplateTests.java

@@ -18,6 +18,7 @@ package org.springframework.messaging.core;
 
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -56,6 +57,7 @@ public class GenericMessagingTemplateTests {
 
 	@Test
 	public void sendAndReceive() {
+
 		SubscribableChannel channel = new ExecutorSubscribableChannel(this.executor);
 		channel.subscribe(new MessageHandler() {
 			@Override
@@ -66,12 +68,13 @@ public class GenericMessagingTemplateTests {
 		});
 
 		String actual = this.template.convertSendAndReceive(channel, "request", String.class);
-
 		assertEquals("response", actual);
 	}
 
 	@Test
 	public void sendAndReceiveTimeout() throws InterruptedException {
+
+		final AtomicReference<Throwable> failure = new AtomicReference<Throwable>();
 		final CountDownLatch latch = new CountDownLatch(1);
 
 		this.template.setReceiveTimeout(1);
@@ -85,14 +88,17 @@ public class GenericMessagingTemplateTests {
 					Thread.sleep(500);
 					MessageChannel replyChannel = (MessageChannel) message.getHeaders().getReplyChannel();
 					replyChannel.send(new GenericMessage<String>("response"));
-					fail("Expected exception");
+					failure.set(new IllegalStateException("Expected exception"));
 				}
 				catch (InterruptedException e) {
-					fail("Unexpected exception " + e.getMessage());
+					failure.set(e);
 				}
 				catch (MessageDeliveryException ex) {
-					assertEquals("Reply message received but the receiving thread has already received a reply",
-							ex.getMessage());
+					String expected = "Reply message received but the receiving thread has exited due to a timeout";
+					String actual = ex.getMessage();
+					if (!expected.equals(actual)) {
+						failure.set(new IllegalStateException("Unexpected error: '" + actual + "'"));
+					}
 				}
 				finally {
 					latch.countDown();
@@ -101,8 +107,11 @@ public class GenericMessagingTemplateTests {
 		});
 
 		assertNull(this.template.convertSendAndReceive(channel, "request", String.class));
-
 		assertTrue(latch.await(1000, TimeUnit.MILLISECONDS));
+
+		if (failure.get() != null) {
+			throw new AssertionError(failure.get());
+		}
 	}
 
 }