Polish "Allow configuring a TaskExecutor even if an Executor is present"

See gh-44659

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/task/TaskExecutorConfigurations.java

@@ -37,7 +37,6 @@ import org.springframework.context.annotation.Lazy;
 import org.springframework.core.task.SimpleAsyncTaskExecutor;
 import org.springframework.core.task.TaskDecorator;
 import org.springframework.core.task.TaskExecutor;
-import org.springframework.scheduling.annotation.AsyncAnnotationBeanPostProcessor;
 import org.springframework.scheduling.annotation.AsyncConfigurer;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
@@ -146,8 +145,7 @@ class TaskExecutorConfigurations {
 	}
 
 	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnMissingBean(name = AsyncAnnotationBeanPostProcessor.DEFAULT_TASK_EXECUTOR_BEAN_NAME,
-			value = AsyncConfigurer.class)
+	@ConditionalOnMissingBean(AsyncConfigurer.class)
 	static class AsyncConfigurerConfiguration {
 
 		@Bean

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/task/TaskExecutionAutoConfigurationTests.java

@@ -30,6 +30,7 @@ import org.junit.jupiter.api.condition.JRE;
 import org.junit.jupiter.api.extension.ExtendWith;
 
 import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
 import org.springframework.beans.factory.support.BeanDefinitionOverrideException;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.task.SimpleAsyncTaskExecutorBuilder;
@@ -239,6 +240,21 @@ class TaskExecutionAutoConfigurationTests {
 				.isInstanceOf(BeanDefinitionOverrideException.class));
 	}
 
+	@Test
+	void taskExecutorWhenModeIsForceAndHasCustomBFPPCanRestoreTaskExecutorAlias() {
+		this.contextRunner.withBean("customTaskExecutor", Executor.class, SyncTaskExecutor::new)
+			.withPropertyValues("spring.task.execution.mode=force")
+			.withBean(BeanFactoryPostProcessor.class,
+					() -> (beanFactory) -> beanFactory.registerAlias("applicationTaskExecutor", "taskExecutor"))
+			.run((context) -> {
+				assertThat(context.getBeansOfType(Executor.class)).hasSize(2)
+					.containsKeys("customTaskExecutor", "applicationTaskExecutor");
+				assertThat(context).hasBean("taskExecutor");
+				assertThat(context.getBean("taskExecutor")).isSameAs(context.getBean("applicationTaskExecutor"));
+
+			});
+	}
+
 	@Test
 	@EnabledForJreRange(min = JRE.JAVA_21)
 	void whenVirtualThreadsAreEnabledAndCustomTaskExecutorIsDefinedThenSimpleAsyncTaskExecutorThatUsesVirtualThreadsBacksOff() {
@@ -294,18 +310,18 @@ class TaskExecutionAutoConfigurationTests {
 	}
 
 	@Test
-	void enableAsyncUsesCustomExecutorWhenModeIsForceAndHasCustomTaskExecutorWithReservedName() {
+	void enableAsyncUsesAutoConfiguredExecutorWhenModeIsForceAndHasCustomTaskExecutorWithReservedName() {
 		this.contextRunner
 			.withPropertyValues("spring.task.execution.thread-name-prefix=auto-task-",
 					"spring.task.execution.mode=force")
 			.withBean("taskExecutor", Executor.class, () -> createCustomAsyncExecutor("custom-task-"))
 			.withUserConfiguration(AsyncConfiguration.class, TestBean.class)
 			.run((context) -> {
-				assertThat(context).doesNotHaveBean(AsyncConfigurer.class);
+				assertThat(context).hasSingleBean(AsyncConfigurer.class);
 				assertThat(context.getBeansOfType(Executor.class)).hasSize(2);
 				TestBean bean = context.getBean(TestBean.class);
 				String text = bean.echo("something").get();
-				assertThat(text).contains("custom-task-").contains("something");
+				assertThat(text).contains("auto-task-").contains("something");
 			});
 	}