Unit testing Vertx - java.util.concurrent.TimeoutException

Question

I am trying to unit test a http call from vertx WebClient uing VertxUnitRunner and RXified version of vertx.

The problem is my unit test always fail with a timeout exception. Is there a different way to unit test WebClient http calls? Below is my code:

import io.vertx.core.AsyncResult;
import io.vertx.core.http.HttpClientOptions;
import io.vertx.core.http.HttpServerOptions;
import io.vertx.ext.unit.TestContext;
import io.vertx.ext.unit.junit.VertxUnitRunner;
import io.vertx.rxjava.core.Vertx;
import io.vertx.rxjava.core.buffer.Buffer;
import io.vertx.rxjava.core.http.HttpServer;
import io.vertx.rxjava.ext.web.client.HttpResponse;
import io.vertx.rxjava.ext.web.client.WebClient;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import rx.Single;


@RunWith(VertxUnitRunner.class)
public class MyVertxTest {

    private Vertx vertx;
    private WebClient client;

    @Before
    public void setUp() throws Exception {
        vertx = Vertx.vertx();
    }

    @Test
    public void testGetContactDetails(TestContext context) {

        System.out.println("start");
        long start = System.currentTimeMillis();
        HttpServer server = vertx.createHttpServer(new HttpServerOptions().setPort(TEST_SERVER_PORT));

        server.requestStream().handler(req -> {
            req.response().setChunked(true).write("foo bar").end();
        });

        System.out.println("created server");

        try {
            server.listen(9000, "localhost", (AsyncResult<HttpServer> ar) -> {

                client = WebClient.wrap(vertx.createHttpClient(new HttpClientOptions()));

                System.out.println("created client");

                Single<HttpResponse<Buffer>> single = client
                        .get(9000, "localhost", "/foo")
                        .rxSend();

                single.subscribe(s -> {
                    System.out.println("inside subscribe");
                    context.assertEquals("foo bar", s.bodyAsString());
                }, e -> {
                    context.fail(e);
                });
            });

            context.async().await();
            System.out.println("total time : " + (System.currentTimeMillis() - start / 1000)+" seconds);

        } catch (Exception e) {
            context.fail(e);
        } finally {
            server.close();
        }
    }
}

The test always fails due to timeout after 120 seconds

OUTPUT

start
created server
created client
inside subscribe
total time : 120

java.util.concurrent.TimeoutException
    at io.vertx.ext.unit.impl.TestContextImpl$Step.lambda$run$0(TestContextImpl.java:112)
    at java.lang.Thread.run(Thread.java:745)

Answer 1

Because yours usage of async are wrong. It's similar java CountDownLatch. It's described in docs

So proper usage would be:

        Async async = context.async(); //here

        server.listen(9000, "localhost", (AsyncResult<HttpServer> ar) -> {

            client = WebClient.wrap(vertx.createHttpClient(new HttpClientOptions()));

            System.out.println("created client");

            Single<HttpResponse<Buffer>> single = client
              .get(9000, "localhost", "/foo")
              .rxSend().subscribeOn(Schedulers.io());

            single.subscribe(s -> {
                System.out.println("inside subscribe");
                context.assertEquals("foo bar", s.bodyAsString());
                async.complete(); //here
            }, e -> {
                context.fail(e);
            });
        });

        async.awaitSuccess();

Also you can make your code blocking to avoid async testing:

        Single<HttpServer> obs = server.rxListen(9000, "localhost");
        obs.toBlocking().value(); //here

        client = WebClient.wrap(vertx.createHttpClient(new HttpClientOptions()));

        System.out.println("created client");

        Single<HttpResponse<Buffer>> single = client
          .get(9000, "localhost", "/foo")
          .rxSend().subscribeOn(Schedulers.io());

        Assert.assertEquals(single.toBlocking().value().bodyAsString(), "foo bar"); //here