#28518 Add unit tests for SingleIndexReviser (#28932)

* #28518 Add unit tests for SingleIndexReviser

* #28518 Add unit tests for SingleIndexReviser

kernel/single/core/src/test/java/org/apache/shardingsphere/single/metadata/reviser/index/SingleIndexReviserTest.java

@@ -0,0 +1,45 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.shardingsphere.single.metadata.reviser.index;
+
+import org.apache.shardingsphere.infra.database.core.metadata.data.model.IndexMetaData;
+import org.junit.jupiter.api.Test;
+
+import java.util.Optional;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class SingleIndexReviserTest {
+
+    @Test
+    void assertReviserReturnsRevisedIndex() {
+        IndexMetaData originalMetaData = new IndexMetaData("test_idx_tableName");
+        originalMetaData.getColumns().add("column1");
+        originalMetaData.getColumns().add("column2");
+        originalMetaData.setUnique(true);
+        SingleIndexReviser reviser = new SingleIndexReviser();
+        Optional<IndexMetaData> optionalRevised = reviser.revise("tableName", originalMetaData, null);
+        assertTrue(optionalRevised.isPresent());
+        IndexMetaData actual = optionalRevised.get();
+        assertThat(originalMetaData.isUnique(), is(actual.isUnique()));
+        assertThat(originalMetaData.getColumns(), is(actual.getColumns()));
+        assertThat("test_idx", is(actual.getName()));
+    }
+}