INT-2666 Fix NPE in SimpleMessageStore

INT-2666 polished test

Polishing

spring-integration-core/src/test/java/org/springframework/integration/store/SimpleMessageGroupTests.java

@@ -1,17 +1,20 @@
 package org.springframework.integration.store;
 
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.mock;
+
 import java.lang.reflect.Constructor;
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 
 import org.junit.Test;
 
 import org.springframework.integration.Message;
 import org.springframework.integration.support.MessageBuilder;
 
-import static org.hamcrest.CoreMatchers.is;
-
-import static org.junit.Assert.assertThat;
-
 /**
  * @author Iwein Fuld
  * @author Oleg Zhurakousky
@@ -19,7 +22,7 @@ import static org.junit.Assert.assertThat;
  */
 public class SimpleMessageGroupTests {
 
-	private Object key = new Object();
+	private final Object key = new Object();
 
 	private SimpleMessageGroup group = new SimpleMessageGroup(Collections.<Message<?>> emptyList(), key);
 
@@ -53,4 +56,16 @@ public class SimpleMessageGroupTests {
 		group.add(message2);
 		assertThat(group.canAdd(message1), is(true));
 	}
+
+	@Test // shoudl not fail with NPE (see INT-2666)
+	public void shouldIgnoreNullValuesWhenInitializedWithCollectionContainingNulls() throws Exception{
+		Message<?> m1 = mock(Message.class);
+		Message<?> m2 = mock(Message.class);
+		final List<Message<?>> messages = new ArrayList<Message<?>>();
+		messages.add(m1);
+		messages.add(null);
+		messages.add(m2);
+		SimpleMessageGroup grp = new SimpleMessageGroup(messages, 1);
+		assertEquals(2, grp.getMessages().size());
+	}
 }