Add nullability annotations to tests in module/spring-boot-amqp

See gh-47263

module/spring-boot-amqp/build.gradle

@@ -55,3 +55,11 @@ dependencies {
 
 	testRuntimeOnly("ch.qos.logback:logback-classic")
 }
+
+tasks.named("compileTestJava") {
+	options.nullability.checking = "tests"
+}
+
+tasks.named("compileDockerTestJava") {
+	options.nullability.checking = "tests"
+}

module/spring-boot-amqp/src/test/java/org/springframework/boot/amqp/autoconfigure/RabbitAutoConfigurationTests.java

@@ -572,7 +572,9 @@ class RabbitAutoConfigurationTests {
 			assertThat(rabbitListenerContainerFactory).extracting("taskExecutor")
 				.isInstanceOf(VirtualThreadTaskExecutor.class);
 			Object taskExecutor = ReflectionTestUtils.getField(rabbitListenerContainerFactory, "taskExecutor");
+			assertThat(taskExecutor).isNotNull();
 			Object virtualThread = ReflectionTestUtils.getField(taskExecutor, "virtualThreadFactory");
+			assertThat(virtualThread).isNotNull();
 			Thread threadCreated = ((ThreadFactory) virtualThread).newThread(mock(Runnable.class));
 			assertThat(threadCreated.getName()).containsPattern("rabbit-simple-[0-9]+");
 		});
@@ -588,7 +590,9 @@ class RabbitAutoConfigurationTests {
 			assertThat(rabbitListenerContainerFactory).extracting("taskExecutor")
 				.isInstanceOf(VirtualThreadTaskExecutor.class);
 			Object taskExecutor = ReflectionTestUtils.getField(rabbitListenerContainerFactory, "taskExecutor");
+			assertThat(taskExecutor).isNotNull();
 			Object virtualThread = ReflectionTestUtils.getField(taskExecutor, "virtualThreadFactory");
+			assertThat(virtualThread).isNotNull();
 			Thread threadCreated = ((ThreadFactory) virtualThread).newThread(mock(Runnable.class));
 			assertThat(threadCreated.getName()).containsPattern("rabbit-direct-[0-9]+");
 		});

module/spring-boot-amqp/src/test/java/org/springframework/boot/amqp/health/RabbitHealthIndicatorTests.java

@@ -45,12 +45,15 @@ import static org.mockito.Mockito.mock;
 class RabbitHealthIndicatorTests {
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private RabbitTemplate rabbitTemplate;
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private Channel channel;
 
 	@Test
+	@SuppressWarnings("NullAway") // Test null check
 	void createWhenRabbitTemplateIsNullShouldThrowException() {
 		assertThatIllegalArgumentException().isThrownBy(() -> new RabbitHealthIndicator(null))
 			.withMessageContaining("'rabbitTemplate' must not be null");