DATAMONGO-1907 - Polishing.

Rename test method to reflect test subject.

Switch from flatMap(…) to map(…) to avoid overhead of Mono creation.

Original pull request: #541.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/SimpleReactiveMongoRepository.java

@@ -92,12 +92,12 @@ public class SimpleReactiveMongoRepository<T, ID extends Serializable> implement
 		q.limit(2);
 
 		return mongoOperations.find(q, example.getProbeType(), entityInformation.getCollectionName()).buffer(2)
-				.flatMap(vals -> {
+				.map(vals -> {
 
 					if (vals.size() > 1) {
-						return Mono.error(new IncorrectResultSizeDataAccessException(1));
+						throw new IncorrectResultSizeDataAccessException(1);
 					}
-					return Mono.just(vals.iterator().next());
+					return vals.iterator().next();
 				}).next();
 	}
 
@@ -315,8 +315,7 @@ public class SimpleReactiveMongoRepository<T, ID extends Serializable> implement
 
 		Assert.notNull(entityStream, "The given Publisher of entities must not be null!");
 
-		return Flux.from(entityStream)
+		return Flux.from(entityStream).flatMap(entity -> entityInformation.isNew(entity) ? //
-				.flatMap(entity -> entityInformation.isNew(entity) ? //
 				mongoOperations.insert(entity, entityInformation.getCollectionName()).then(Mono.just(entity)) : //
 				mongoOperations.save(entity, entityInformation.getCollectionName()).then(Mono.just(entity)));
 	}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/SimpleReactiveMongoRepositoryTests.java

@@ -443,7 +443,7 @@ public class SimpleReactiveMongoRepositoryTests implements BeanClassLoaderAware,
 	}
 
 	@Test // DATAMONGO-1907
-	public void existsByExampleShouldReturnNonExistingWithoutThrowException() {
+	public void findOneByExampleWithoutResultShouldCompleteEmpty() {
 
 		Example<ReactivePerson> example = Example.of(new ReactivePerson("foo", "bar", -1));