Vert.x for Scala also brings a test support artifact, which helps to write ScalaTest specifications. This section shows how to install it and how to use it when writing specs.

Installation

To install, add the vertx-lang-scala-test_3 artifact to your build descriptor.

sbt

libraryDependencies ++= Seq(
  "io.vertx" %% "vertx-lang-scala-test" % "4.5.11-SNAPSHOT" % Test,
)

Gradle

testImplementation "io.vertx:vertx-lang-scala-test_3:4.5.11-SNAPSHOT"

Maven

<dependency>
  <groupId>io.vertx</groupId>
  <artifactId>vertx-lang-scala-test_3</artifactId>
  <version>4.5.11-SNAPSHOT</version>
  <scope>test</scope>
</dependency>

Writing Verticle Tests

Let's assume we have written a Verticle like this:

import io.vertx.ext.web.Router
import io.vertx.lang.scala.*
import io.vertx.lang.scala.ImplicitConversions.vertxFutureToScalaFuture
import io.vertx.lang.scala.json.Json
import scala.concurrent.Future
import scala.language.implicitConversions

final class MyWebVerticle extends ScalaVerticle:
  override def asyncStart: Future[Unit] =
    val router = Router.router(vertx)
    router.get("/ping").handler(_.json(Json.obj("""{ "message": "pong" }""")))
    vertx.createHttpServer()
      .requestHandler(router)
      .listen(8080)
      .mapEmpty[Unit]()

Using vertx-lang-scala-test, we can write a ScalaTest spec like this:

import io.vertx.lang.scala.*
import io.vertx.lang.scala.json.Json
import io.vertx.lang.scala.testing.VerticleTesting
import io.vertx.lang.scala.ImplicitConversions.vertxFutureToScalaFuture
import io.vertx.scala.core.*
import org.scalatest.matchers.should.Matchers
import scala.language.implicitConversions
final class MyWebVerticleSpec extends VerticleTesting[MyWebVerticle], Matchers:

  "MyWebVerticle" should "pong" in {
    val client = vertx.createHttpClient()

    for {
      req  <- client.request(RequestOptions(absoluteURI = "http://127.0.0.1:8888/ping"))
      res  <- req.send
      body <- res.body
      assertion = body.toJson should equal(Json.obj("""{ "message": "pong" }"""))
    } yield assertion
  }

That's it, vertx-lang-scala-test takes care of deploying MyVerticle to a Vertx instance and makes it ready for testing.

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