Rx-fied vertx.io and junit testing - junit

Question

I'm loving vertx.io in my spare time. Just now I am switching from plain vertx to rxjava2-fied (vertx-rx-java2, 3.5.1) api version and my VertxUnitRunner tests doesn't complete anymore:
#Test
public void computeSomethingByNullPlan(TestContext ctx) {
query = null;
Async async = ctx.async();
vertx.eventBus().send(HANDLER_ADDRESS, query,
new DeliveryOptions().addHeader("action", ACTION), msg -> {
if (msg.failed())
log.error(msg.cause());
ctx.assertTrue(msg.succeeded());
ctx.assertTrue(new
JsonArray(msg.result().body().toString()).isEmpty());
async.complete();
});
}
test runs fine but once async.complete(); instruction is hit test does not return but hangs. Maybe it is because I'm mixing io.vertx.reactivex.core and io.vertx.core together (e.g.: io.vertx.reactivex.core.Vertx and io.vertx.core.TestContex) or maybe I'm not using the correct VertxUnitRunner.
What am I doing wrong? I search for a while but no success, Is there any example/doc about vertx.io rxjava2 and testing?

Answer 1

i'm able to reproduce the issue of the test "hanging" when this bit:
JsonArray(msg.result().body().toString())
...fails to deserialize the response body as an array of JSON. to verify this, comment out that entire assertion and see if the test completes afterwards. if so, that should narrow down the scope of that particular issue.
it's worth noting that since you're using the Rx-ified version of the API, you can represent asynchronous sources using the standard Rx types (instead of Handler). your test rewritten along those lines (minus the JsonArray stuff) might look something like this:
import io.vertx.ext.unit.Async;
import io.vertx.ext.unit.TestContext;
import io.vertx.ext.unit.junit.VertxUnitRunner;
import io.vertx.reactivex.core.Vertx;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
#RunWith(VertxUnitRunner.class)
public class Blah {
private Vertx vertx;
#Before
public void setUp(TestContext context) {
vertx = Vertx.vertx();
vertx.eventBus().consumer("HANDLER_ADDRESS").handler(message -> {
message.reply("PONG!");
});
}
#Test
public void computeSomethingByNullPlan(TestContext context) {
final String query = "PING?";
final Async async = context.async();
vertx.eventBus().rxSend("HANDLER_ADDRESS", query)
.subscribe(
message -> {
context.assertEquals("PONG!", message.body().toString());
async.complete();
},
context::fail
);
}
}
i hope that helps clear things up!