How to create mock instance of Autowired component in Vert.x - junit

Question

I am trying to create mock instance of the class which is autowired inside Verticle but I am getting it as a null. For synchronous code the way which works is looking not useful for Vert.x.
Verticle is:
#Component
public class MyVerticle extends AbstractVerticle{
#Autowired
private ServiceExecutor serviceExecutor;
#Override
public void start() throws Exception {
super.start();
vertx.eventBus().<String>consumer("address.xyz").handler(handleRequest());
}
private Handler<Message<String>> handleRequest() {
return msg -> {
getSomeData(msg.body().toString())
.setHandler(ar -> {
if(ar.succeeded()){
msg.reply(ar.result());
}else{
msg.reply(ar.cause().getMessage());
}
});
};
}
private Future<String> getSomeData(String inputJson) {
Promise<String> promise = Promise.promise();
String data = serviceExecutor.executeSomeService(inputJson); // Getting NPE here. serviceExecutor is coming as null when trying to create mock of it using Mockito.when.
promise.complete(data);
return promise.future();
}
}
Dependent component is:
#Component
public class ServiceExecutor {
public String executeSomeService(String input){
return "Returning Data";
}
}
Test case is:
import static org.mockito.Mockito.when;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.MockitoAnnotations;
import io.vertx.core.Vertx;
import io.vertx.ext.unit.Async;
import io.vertx.ext.unit.TestContext;
import io.vertx.ext.unit.junit.VertxUnitRunner;
#RunWith(VertxUnitRunner.class)
public class MyVerticleTest {
#Mock
private ServiceExecutor serviceExecutor;
private Vertx vertx;
#Before
public void setup(TestContext ctx){
MockitoAnnotations.initMocks(this);
Async async = ctx.async();
this.vertx = Vertx.vertx();
vertx.deployVerticle(MyVerticle.class.getName(), h -> {
if(h.succeeded()){
async.complete();
}else{
ctx.fail();
}
});
}
#Test
public void test_consumption(TestContext ctx) {
Async async = ctx.async();
when(serviceExecutor.executeSomeService(Mockito.anyString())).thenReturn("Returning Data");
vertx.eventBus().request("address.xyz","message", h ->{
if(h.succeeded()){
ctx.assertEquals("Returning Data",h.result().body().toString());
async.complete();
}else{
ctx.fail(h.cause());
}
});
}
}
Above Test Case works well if I don't use autowired instance to call a method to get the date. But if used it (which I must do to get the data), it is giving NPE at MyVerticle->getSomeData() method when trying to use serviceExecutor object as a mock. This approach works very well for Synchronous code flow but for Vert.x looks like it won't help. So need help here to mock the autowired instance serviceExecutor inside Verticle.

Answer 1

Add a constructor in your MyVerticle
public MyVerticle(ApplicationContext context) {
context.getAutowireCapableBeanFactory().autowireBean(this);
}
and deploy your verticle something like vertx.deployVerticle(new MyVerticle(context),...
I have application context while deploying the verticle and thats what I am passing in the constructor. Check if this works for you.