Override LazyTraceThreadPoolTaskExecutor.getQueueSize() to return del… (#2316)

* Override LazyTraceThreadPoolTaskExecutor.getQueueSize() to return delegate's value (#2315)

* Update LazyTraceThreadPoolTaskExecutorTests.java

---------

Co-authored-by: Marcin Grzejszczak <marcin@grzejszczak.pl>

spring-cloud-sleuth-instrumentation/src/main/java/org/springframework/cloud/sleuth/instrument/async/LazyTraceThreadPoolTaskExecutor.java

@@ -177,6 +177,11 @@ public class LazyTraceThreadPoolTaskExecutor extends ThreadPoolTaskExecutor {
 		return this.delegate.getQueueCapacity();
 	}
 
+	@Override
+	public int getQueueSize() {
+		return this.delegate.getQueueSize();
+	}
+
 	@Override
 	public void destroy() {
 		this.delegate.destroy();

spring-cloud-sleuth-instrumentation/src/test/java/org/springframework/cloud/sleuth/instrument/async/LazyTraceThreadPoolTaskExecutorTests.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2013-2023 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.springframework.cloud.sleuth.instrument.async;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
+
+@ExtendWith(MockitoExtension.class)
+public class LazyTraceThreadPoolTaskExecutorTests {
+
+	private static final String BEAN_NAME = "mock";
+
+	@Mock(lenient = true)
+	private BeanFactory beanFactory;
+
+	@Mock(lenient = true)
+	private ThreadPoolTaskExecutor delegate;
+
+	private LazyTraceThreadPoolTaskExecutor executor;
+
+	@BeforeEach
+	public void setup() {
+		this.executor = spy(new LazyTraceThreadPoolTaskExecutor(beanFactory, delegate, BEAN_NAME));
+	}
+
+	@Test
+	public void should_delegate_getQueueSize() {
+		final int expected = 1000;
+		doReturn(expected).when(delegate).getQueueSize();
+
+		final int actual = executor.getQueueSize();
+
+		assertThat(actual).isEqualTo(expected);
+	}
+
+}