DATAMONGO-647 - Added test case to show that field names are mapped correctly.

Additional test added to check if the issue has truly been resolved by DATAMONGO-888.

Original pull request: spring-projects#181.
Related pull Request: spring-projects#162.
Related ticket: DATAMONGO-888.

Author: christophstrobl

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/QueryMapperUnitTests.java

@@ -34,6 +34,8 @@
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.springframework.data.annotation.Id;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.mongodb.MongoDbFactory;
 import org.springframework.data.mongodb.core.DBObjectTestUtils;
 import org.springframework.data.mongodb.core.Person;
@@ -49,6 +51,7 @@
 
 import com.mongodb.BasicDBList;
 import com.mongodb.BasicDBObject;
+import com.mongodb.BasicDBObjectBuilder;
 import com.mongodb.DBObject;
 import com.mongodb.QueryBuilder;
 
@@ -586,6 +589,17 @@ public void classInformationShouldNotBePresentInDBObjectUsedInFinderMethods() {
 		assertThat(dbo.toString(), equalTo("{ \"embedded\" : { \"$in\" : [ { \"_id\" : \"1\"} , { \"_id\" : \"2\"}]}}"));
 	}
 
+	/**
+	 * @see DATAMONGO-647
+	 */
+	@Test
+	public void customizedFieldNameShouldBeMappedCorrectlyWhenApplyingSort() {
+
+		Query query = query(where("field").is("bar")).with(new Sort(Direction.DESC, "field"));
+		DBObject dbo = mapper.getMappedObject(query.getSortObject(), context.getPersistentEntity(CustomizedField.class));
+		assertThat(dbo, equalTo(new BasicDBObjectBuilder().add("foo", -1).get()));
+	}
+
 	@Document
 	public class Foo {
 		@Id private ObjectId id;