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:

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   <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.

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   $ 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.

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   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.

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   mvn clean verify

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