Add nullability annotations to tests in module/spring-boot-data-r2dbc

See gh-47263

module/spring-boot-data-r2dbc/build.gradle

@@ -40,5 +40,11 @@ dependencies {
 	testImplementation("io.projectreactor:reactor-test")
 	testImplementation("io.r2dbc:r2dbc-h2")
 
+	testCompileOnly("com.google.code.findbugs:jsr305")
+
 	testRuntimeOnly("ch.qos.logback:logback-classic")
 }
+
+tasks.named("compileTestJava") {
+	options.nullability.checking = "tests"
+}

module/spring-boot-data-r2dbc/src/test/java/org/springframework/boot/data/r2dbc/autoconfigure/DataR2dbcAutoConfigurationTests.java

@@ -50,6 +50,7 @@ class DataR2dbcAutoConfigurationTests {
 		this.contextRunner.withUserConfiguration(TestConfiguration.class).run((context) -> {
 			R2dbcMappingContext mappingContext = context.getBean(R2dbcMappingContext.class);
 			ManagedTypes managedTypes = (ManagedTypes) ReflectionTestUtils.getField(mappingContext, "managedTypes");
+			assertThat(managedTypes).isNotNull();
 			assertThat(managedTypes.toList()).containsOnly(City.class);
 		});
 	}