Addressed review comments

Signed-off-by: Krishna Kondaka <krishkdk@amazon.com>

Author: kkondaka

data-prepper-plugins/mutate-event-processors/src/test/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessorTests.java

@@ -65,7 +65,7 @@ void invalid_rename_when_throws_InvalidPluginConfigurationException() {
     }
 
     @Test
-    void invalid_config_tests_with_entries_and_transform_options() throws NoSuchFieldException, IllegalAccessException {
+    void invalid_config_tests_with_entries_and_transform_options_both_present() throws NoSuchFieldException, IllegalAccessException {
         final String renameWhen = UUID.randomUUID().toString();
         List<RenameKeyProcessorConfig.Entry> entries = createListOfEntries(createEntry("message", null,"newMessage", true, renameWhen));
 
@@ -74,13 +74,32 @@ void invalid_config_tests_with_entries_and_transform_options() throws NoSuchFiel
         ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "entries", entries);
         ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "transformOption", TransformOption.LOWERCASE);
         assertFalse(renameKeyProcessorConfig.isValidConfig());
+    }
+
+    @Test
+    void invalid_config_tests_with_entries_and_transform_options_both_not_present() throws NoSuchFieldException, IllegalAccessException {
+        RenameKeyProcessorConfig renameKeyProcessorConfig = new RenameKeyProcessorConfig();
+        ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "entries", null);
+        ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "transformOption", TransformOption.NONE);
+        assertFalse(renameKeyProcessorConfig.isValidConfig());
+    }
+
+    @Test
+    void invalid_config_tests_with_entries_and_transform_options_valid_entries() throws NoSuchFieldException, IllegalAccessException {
+        final String renameWhen = UUID.randomUUID().toString();
+        List<RenameKeyProcessorConfig.Entry> entries = createListOfEntries(createEntry("message", null,"newMessage", true, renameWhen));
+        RenameKeyProcessorConfig renameKeyProcessorConfig = new RenameKeyProcessorConfig();
+        ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "entries", entries);
         ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "transformOption", TransformOption.NONE);
         assertTrue(renameKeyProcessorConfig.isValidConfig());
-        ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "transformOption", TransformOption.LOWERCASE);
+    }
+
+    @Test
+    void invalid_config_tests_with_entries_and_transform_options_valid_transformation() throws NoSuchFieldException, IllegalAccessException {
+        RenameKeyProcessorConfig renameKeyProcessorConfig = new RenameKeyProcessorConfig();
         ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "entries", null);
+        ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "transformOption", TransformOption.UPPERCASE);
         assertTrue(renameKeyProcessorConfig.isValidConfig());
-        ReflectivelySetField.setField(RenameKeyProcessorConfig.class, renameKeyProcessorConfig, "transformOption", TransformOption.NONE);
-        assertFalse(renameKeyProcessorConfig.isValidConfig());
     }
 
     @Test