Writing integration tests for RESTful web services using Arquillian

23 Sep 2023

Integration testing is an important aspect of software development, especially when it comes to RESTful web services. It ensures that different components of the system work together seamlessly and adhere to the expected behavior.

In this blog post, we will explore how to write integration tests for RESTful web services using Arquillian. Arquillian is a powerful testing framework that simplifies the process of setting up and running integration tests.

Prerequisites

Before diving into the test code, let’s ensure that we have the necessary prerequisites in place:

The RESTful web service application that needs to be tested
A Java IDE (such as IntelliJ or Eclipse) for writing and running the tests
Maven as the build tool to manage the dependencies

Setting up the Arquillian Environment

To begin, we need to set up the Arquillian environment in our project. First, add the Arquillian dependencies to the pom.xml file:

<dependencies>
    <!-- Arquillian Core -->
    <dependency>
        <groupId>org.jboss.arquillian.core</groupId>
        <artifactId>arquillian-core</artifactId>
        <version>1.5.0.Final</version>
        <scope>test</scope>
    </dependency>
   
    <!-- Arquillian JUnit Integration -->
    <dependency>
        <groupId>org.jboss.arquillian.junit</groupId>
        <artifactId>arquillian-junit-container</artifactId>
        <version>1.5.0.Final</version>
        <scope>test</scope>
    </dependency>
   
    <!-- Arquillian REST Extension -->
    <dependency>
        <groupId>org.jboss.arquillian.extension</groupId>
        <artifactId>arquillian-rest-extension</artifactId>
        <version>1.0.0.Alpha3</version>
        <scope>test</scope>
    </dependency>
   
    <!-- Other dependencies -->
    ...
</dependencies>

Next, create a new class in the test package, e.g., RestfulWebServiceIT.java. This class will contain the integration test methods.

Writing Integration Tests

Let’s assume we have a RESTful web service with an endpoint /api/employees that returns a list of employees.

@Path("/api/employees")
public class EmployeeResource {
   
    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public List<Employee> getEmployees() {
        // Retrieve and return the list of employees
    }
}

To test this endpoint, we can write an integration test using Arquillian. Here’s an example of how the test method would look like:

@RunWith(Arquillian.class)
public class RestfulWebServiceIT {

    @Deployment
    public static WebArchive createDeployment() {
        return ShrinkWrap.create(WebArchive.class, "test.war")
                .addClasses(EmployeeResource.class)
                .addAsWebInfResource(EmptyAsset.INSTANCE, "beans.xml");
    }

    @ArquillianResource
    private URL base;

    @Test
    public void testGetEmployees() {
        given()
                .when().get(new URL(base, "/api/employees").toString())
                .then()
                .statusCode(200)
                .contentType(MediaType.APPLICATION_JSON)
                .body("size()", greaterThan(0));
    }
}

In this test, we use the given(), when(), and then() methods provided by the REST-assured library to construct and validate the HTTP request/response. The @ArquillianResource annotation injects the base URL of the deployed application.

Running the Integration Tests

To run the integration tests, execute the following command in the terminal:

mvn clean test

Arquillian will automatically deploy the application and run the integration tests. The results will be displayed in the console, indicating whether the tests have passed or failed.

Conclusion

In this blog post, we explored how to write integration tests for RESTful web services using Arquillian. By leveraging Arquillian’s capabilities, we can easily set up and run integration tests that validate the behavior of our web services.