How do I use a Citrus mail endpoint in an Arquillian test on JEE server - jboss-arquillian

Question

I have a Java webapp where a REST call triggers a mail sent through a javax.mail.Session. The application is deployed as a .war archive that I want to test inside a JBoss EAP 7.2 server.
I am using Arquillian 1.5.0.Final and Citrus Framework version 2.8.0. My build system is Gradle 5.x and everything is using a Java 8 runtime.
I would like to create a Citrus mail endpoint and use Arquillian to provide this inside the JEE container. My experience with these frameworks is limited to a few days, so I'm starting with a sample application to gain more knowledge:
I have the following working against a simple web endpoint (The HelloServlet from https://guides.gradle.org/building-java-web-applications/):
#RunWith(Arquillian.class)
public class HelloServletTest {
#CitrusFramework
private Citrus citrusFramework;
#ArquillianResource
private URL baseUri;
private String serviceUri;
#Deployment(testable = false)
public static WebArchive createDeployment() {
final WebArchive war = ShrinkWrap.create(WebArchive.class)
.addClass(HelloServlet.class)
.addAsManifestResource(EmptyAsset.INSTANCE, "beans.xml");
// [...]
return war;
}
#Before
public void setUp() throws Exception {
serviceUri = new URL(baseUri, "hello").toExternalForm();
}
#Test
#CitrusTest
public void smokeTest(#CitrusResource TestDesigner designer) throws InterruptedException {
System.err.println("ServiceURI: " + serviceUri);
designer.send(serviceUri)
.message(new HttpMessage("?name=Jacob")
.method(HttpMethod.POST));
designer.receive(serviceUri).message(new HttpMessage("").status(HttpStatus.OK));
citrusFramework.run(designer.getTestCase());
}
}
I use #Deployment(testable=false) as this example runs a client-side test. However, my end goal is to use Citrus inside the container so my understanding is that I need to have #Deployment(testable=true). But when I run the test with testable=true a NPE is thrown:
java.lang.NullPointerException
at com.consol.citrus.annotations.CitrusAnnotations.injectAll(CitrusAnnotations.java:61)
at com.consol.citrus.arquillian.enricher.CitrusTestEnricher.enrich(CitrusTestEnricher.java:57)
at org.jboss.arquillian.junit.RulesEnricher.enrichInstances(RulesEnricher.java:85)
at org.jboss.arquillian.junit.RulesEnricher.enrichStatement(RulesEnricher.java:77)
[...]
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:103)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:90)
at org.jboss.arquillian.container.test.impl.client.ContainerEventController.createContext(ContainerEventController.java:128)
at org.jboss.arquillian.container.test.impl.client.ContainerEventController.createBeforeContext(ContainerEventController.java:114)
[...]
at org.jboss.arquillian.test.impl.EventTestRunnerAdaptor.fireCustomLifecycle(EventTestRunnerAdaptor.java:159)
at org.jboss.arquillian.junit.Arquillian$7.evaluate(Arquillian.java:273)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
[...]
at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
[...]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
at java.lang.Thread.run(Thread.java:748)
My arquillian.xml is
<?xml version="1.0" encoding="UTF-8"?>
<arquillian xmlns="http://jboss.org/schema/arquillian" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://jboss.org/schema/arquillian http://jboss.org/schema/arquillian/arquillian_1_0.xsd">
<defaultProtocol type="Servlet 3.0"/>
<engine>
<property name="deploymentExportPath">build/deployments</property>
</engine>
<container qualifier="wildfly-managed" default="true">
</container>
<extension qualifier="citrus">
<property name="autoPackage">false</property>
<property name="citrusVersion">2.8.0</property>
</extension>
</arquillian>
My citrus-context.xml is
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:citrus-mail="http://www.citrusframework.org/schema/mail/config"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.citrusframework.org/schema/mail/config http://www.citrusframework.org/schema/mail/config/citrus-mail-config.xsd">
<!-- Mail server mock -->
<citrus-mail:server id="mailServer"
auto-start="true"
port="2222"/>
</beans>
My questions are:
Does my approach make sense? Is it feasible to use Citrus and Arquillian in this way?
Is the NPE exception to be expected or am I missing some dependency or configuration?