Polish apache#4907 : Add test cases for DubboServiceDestroyedEvent

dubbo-config/dubbo-config-api/src/test/java/org/apache/dubbo/config/event/DubboServiceDestroyedEventTest.java

@@ -0,0 +1,58 @@
+/*
+ * 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.dubbo.config.event;
+
+import org.apache.dubbo.config.DubboShutdownHook;
+import org.apache.dubbo.event.EventDispatcher;
+import org.apache.dubbo.event.EventListener;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * {@link DubboServiceDestroyedEvent} Test
+ *
+ * @since 2.7.4
+ */
+public class DubboServiceDestroyedEventTest implements EventListener<DubboServiceDestroyedEvent> {
+
+    private DubboServiceDestroyedEvent event;
+
+    private EventDispatcher eventDispatcher = EventDispatcher.getDefaultExtension();
+
+    private DubboShutdownHook dubboShutdownHook;
+
+    @BeforeEach
+    public void init() {
+        eventDispatcher.removeAllEventListeners();
+        eventDispatcher.addEventListener(this);
+        dubboShutdownHook = DubboShutdownHook.getDubboShutdownHook();
+    }
+
+    @Test
+    public void testOnEvent() {
+        dubboShutdownHook.doDestroy();
+        assertEquals(dubboShutdownHook, event.getSource());
+    }
+
+    @Override
+    public void onEvent(DubboServiceDestroyedEvent event) {
+        this.event = event;
+    }
+}