[Improve] add commonThreadPoll unit test (#2327)

Signed-off-by: yuluo-yx <yuluo08290126@gmail.com>
Co-authored-by: tomsun28 <tomsun28@outlook.com>

common/src/test/java/org/apache/hertzbeat/common/support/CommonThreadPoolTest.java

@@ -0,0 +1,110 @@
+/*
+ * 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.hertzbeat.common.support;
+
+import java.lang.reflect.Field;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.SynchronousQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+/**
+ * test for {@link CommonThreadPool}
+ */
+
+class CommonThreadPoolTest {
+
+	private CommonThreadPool commonThreadPool;
+
+	private ThreadPoolExecutor executorMock;
+
+	@BeforeEach
+	public void setUp() throws Exception {
+
+		commonThreadPool = new CommonThreadPool();
+
+		Field workerExecutorField = CommonThreadPool.class.getDeclaredField("workerExecutor");
+		workerExecutorField.setAccessible(true);
+		executorMock = mock(ThreadPoolExecutor.class);
+		workerExecutorField.set(commonThreadPool, executorMock);
+	}
+
+	@Test
+	public void testExecuteTask() {
+
+		Runnable task = mock(Runnable.class);
+		commonThreadPool.execute(task);
+		verify(executorMock).execute(task);
+	}
+
+	@Test
+	public void testExecuteTaskThrowsEX() {
+
+		Runnable task = mock(Runnable.class);
+		doThrow(RejectedExecutionException.class).when(executorMock).execute(task);
+
+		assertThrows(
+				RejectedExecutionException.class,
+				() -> commonThreadPool.execute(task)
+		);
+	}
+
+	@Test
+	public void testDestroy() throws Exception {
+
+		commonThreadPool.destroy();
+		verify(executorMock).shutdownNow();
+	}
+
+	@Test
+	public void testDestroyWithNull() throws Exception {
+
+		Field workerExecutorField = CommonThreadPool.class.getDeclaredField("workerExecutor");
+		workerExecutorField.setAccessible(true);
+		workerExecutorField.set(commonThreadPool, null);
+
+		commonThreadPool.destroy();
+	}
+
+	@Test
+	public void testInitialization() throws Exception {
+		CommonThreadPool pool = new CommonThreadPool();
+
+		Field workerExecutorField = CommonThreadPool.class.getDeclaredField("workerExecutor");
+		workerExecutorField.setAccessible(true);
+		ThreadPoolExecutor workerExecutor = (ThreadPoolExecutor) workerExecutorField.get(pool);
+
+		assertNotNull(workerExecutor);
+		assertEquals(2, workerExecutor.getCorePoolSize());
+		assertEquals(Integer.MAX_VALUE, workerExecutor.getMaximumPoolSize());
+		assertEquals(10, workerExecutor.getKeepAliveTime(TimeUnit.SECONDS));
+		assertTrue(workerExecutor.getQueue() instanceof SynchronousQueue);
+	}
+
+}