Added unit tests for ShardingSphereDataNode (#28840)

* Added unit tests for ShardingSphereDataNode

* Checkstyle fix, removed underscore from test names

kernel/metadata/core/src/test/java/org/apache/shardingsphere/metadata/persist/node/ShardingSphereDataNodeTest.java

@@ -0,0 +1,133 @@
+/*
+ * 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.metadata.persist.node;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Optional;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+class ShardingSphereDataNodeTest {
+
+    @Test
+    void assertGetShardingSphereDataNodePath() {
+        assertThat(ShardingSphereDataNode.getShardingSphereDataNodePath(), is("/statistics"));
+    }
+
+    @Test
+    void assertGetDatabaseNamePath() {
+        assertThat(ShardingSphereDataNode.getDatabaseNamePath("db_path"), is("/statistics/db_path"));
+    }
+
+    @Test
+    void assertGetTablesPath() {
+        assertThat(ShardingSphereDataNode.getTablesPath("db_name", "db_schema"), is("/statistics/db_name/schemas/db_schema/tables"));
+    }
+
+    @Test
+    void assertGetSchemaDataPath() {
+        assertThat(ShardingSphereDataNode.getSchemaDataPath("db_name", "db_schema"), is("/statistics/db_name/schemas/db_schema"));
+    }
+
+    @Test
+    void assertGetSchemasPath() {
+        assertThat(ShardingSphereDataNode.getSchemasPath("db_name"), is("/statistics/db_name/schemas"));
+    }
+
+    @Test
+    void assertGetTablePath() {
+        assertThat(ShardingSphereDataNode.getTablePath("db_name", "db_schema", "tbl_name"), is("/statistics/db_name/schemas/db_schema/tables/tbl_name"));
+    }
+
+    @Test
+    void assertGetTableRowPath() {
+        assertThat(ShardingSphereDataNode.getTableRowPath("db_name", "db_schema", "tbl_name", "key"), is("/statistics/db_name/schemas/db_schema/tables/tbl_name/key"));
+    }
+
+    @Test
+    void assertGetDatabaseNameHappyPath() {
+        assertThat(ShardingSphereDataNode.getDatabaseName("/statistics/db_name"), is(Optional.of("db_name")));
+    }
+
+    @Test
+    void assertGetDatabaseNameDbNameNotFoundScenario() {
+        assertThat(ShardingSphereDataNode.getDatabaseName("/statistics"), is(Optional.empty()));
+    }
+
+    @Test
+    void assertGetSchemaNameHappyPath() {
+        assertThat(ShardingSphereDataNode.getSchemaName("/statistics/db_name/schemas/db_schema"), is(Optional.of("db_schema")));
+    }
+
+    @Test
+    void assertGetSchemaNameSchemaNameNotFoundScenario() {
+        assertThat(ShardingSphereDataNode.getSchemaName("/statistics/db_name"), is(Optional.empty()));
+    }
+
+    @Test
+    void assertGetDatabaseNameByDatabasePathHappyPath() {
+        assertThat(ShardingSphereDataNode.getDatabaseNameByDatabasePath("/statistics/db_name"), is(Optional.of("db_name")));
+    }
+
+    @Test
+    void assertGetDatabaseNameByDatabasePathDbNameNotFoundScenario() {
+        assertThat(ShardingSphereDataNode.getDatabaseNameByDatabasePath("/statistics"), is(Optional.empty()));
+    }
+
+    @Test
+    void assertGetSchemaNameBySchemaPathHappyPath() {
+        assertThat(ShardingSphereDataNode.getSchemaNameBySchemaPath("/statistics/db_name/schemas/db_schema"), is(Optional.of("db_schema")));
+    }
+
+    @Test
+    void assertGetSchemaNameBySchemaPathSchemaNameNotFoundScenario() {
+        assertThat(ShardingSphereDataNode.getSchemaNameBySchemaPath("/statistics/db_name"), is(Optional.empty()));
+    }
+
+    @Test
+    void assertGetTableNameHappyPath() {
+        assertThat(ShardingSphereDataNode.getTableName("/statistics/db_name/schemas/db_schema/tables/tbl_name"), is(Optional.of("tbl_name")));
+    }
+
+    @Test
+    void assertGetTableNameTableNameNotFoundScenario() {
+        assertThat(ShardingSphereDataNode.getTableName("/statistics/db_name/schemas/db_schema"), is(Optional.empty()));
+    }
+
+    @Test
+    void assertGetTableNameByRowPathHappyPath() {
+        assertThat(ShardingSphereDataNode.getTableNameByRowPath("/statistics/db_name/schemas/db_schema/tables/tbl_name"), is(Optional.of("tbl_name")));
+    }
+
+    @Test
+    void assertGetTableNameByRowPathTableNameNotFoundScenario() {
+        assertThat(ShardingSphereDataNode.getTableNameByRowPath("/statistics/db_name/schemas/db_schema"), is(Optional.empty()));
+    }
+
+    @Test
+    void assertGetRowUniqueKeyHappyPath() {
+        assertThat(ShardingSphereDataNode.getRowUniqueKey("/statistics/db_name/schemas/db_schema/tables/tbl_name/key"), is(Optional.of("key")));
+    }
+
+    @Test
+    void assertGetRowUniqueKeyUniqueKeyNotFoundScenario() {
+        assertThat(ShardingSphereDataNode.getRowUniqueKey("/statistics/db_name/schemas/db_schema/tables/tbl_name"), is(Optional.empty()));
+    }
+}