Chapter 4. Testing your Eclipse Vert.x application with JUnit

Procedure

1. Open the generated pom.xml file and set the version of the Surefire Maven plug-in:

   <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-surefire-plugin</artifactId>
           <version>3.0.0-M5</version>
   </plugin>

2. Create a directory structure src/test/java/com/example/ in the root directory, and navigate to it.

   $ mkdir -p src/test/java/com/example/
   $ cd src/test/java/com/example/

3. Create a Java class file MyTestApp.java containing the application code.

   package com.example;
   
   import static org.junit.jupiter.api.Assertions.assertEquals;
   
   import org.junit.jupiter.api.BeforeEach;
   import org.junit.jupiter.api.DisplayName;
   import org.junit.jupiter.api.Test;
   import org.junit.jupiter.api.extension.ExtendWith;
   
   import io.vertx.core.Vertx;
   import io.vertx.core.http.HttpMethod;
   import io.vertx.junit5.VertxExtension;
   import io.vertx.junit5.VertxTestContext;
   
   @ExtendWith(VertxExtension.class)
   class MyAppTest {
   
     @BeforeEach
     void prepare(Vertx vertx, VertxTestContext testContext) {
       // Deploy the verticle
       vertx.deployVerticle(new MyApp())
         .onSuccess(ok -> testContext.completeNow())
         .onFailure(failure -> testContext.failNow(failure));
     }
   
     @Test
     @DisplayName("Smoke test: check that the HTTP server responds")
     void smokeTest(Vertx vertx, VertxTestContext testContext) {
       // Issue an HTTP request
       vertx.createHttpClient()
         .request(HttpMethod.GET, 8080, "127.0.0.1", "/")
         .compose(request -> request.send())
         .compose(response -> response.body())
         .onSuccess(body -> testContext.verify(() -> {
           // Check the response
           assertEquals("Greetings!", body.toString());
           testContext.completeNow();
         }))
         .onFailure(failure -> testContext.failNow(failure));
     }
   }

4. To run the JUnit test on my application using Maven run the following command from the root directory of the application.

   mvn clean verify

   You can check the test results in the target/surefire-reports. The com.example.MyAppTest.txt file contains the test results.