DATAREDIS-771 - Polishing.

Improve error message for unsupported PartTree keywords.

Original Pull Request: #342

src/main/java/org/springframework/data/redis/repository/query/RedisQueryCreator.java

@@ -70,7 +70,7 @@ public class RedisQueryCreator extends AbstractQueryCreator<KeyValueQuery<RedisO
 				sink.near(getNearPath(part, iterator));
 				break;
 			default:
-				throw new IllegalArgumentException(part.getType() + "is not supported for redis query derivation");
+				throw new IllegalArgumentException(String.format("%s is not supported for Redis query derivation!", part.getType()));
 		}
 
 		return sink;

src/test/java/org/springframework/data/redis/repository/query/RedisQueryCreatorUnitTests.java

@@ -44,6 +44,8 @@ import org.springframework.data.repository.query.ParametersParameterAccessor;
 import org.springframework.data.repository.query.parser.PartTree;
 
 /**
+ * Unit tests for {@link RedisQueryCreator}.
+ *
  * @author Christoph Strobl
  * @author Mark Paluch
  */