Functional Tests in Play! 2 with REST-assured

In the Play! documentation, several flavours of functional testing are mentioned, including starting a HTTP server for the duration of the test – this is very useful for testing web services. In code, this looks like

import static play.test.Helpers.*;
...
@Test
public void testInServer() {
  running(testServer(3333), new Callback0() {
      public void invoke() {
         assertThat(
           WS.url("http://localhost:3333").get().get().status
         ).isEqualTo(OK);
      }
  });
}

A few days ago, when I was looking for a good way to test applications built on a CXF stack, I came across REST-assured. It was simple, elegant and useful so it’s the one I picked. In that case, I had to build some extra support for handling Jetty start-up and shutdown, application loading, etc.

With the full-stack approach of Play, however, you get this support for free out of the box, so all that is left is to integrate the tool of your choice. To add REST-assured to your project, edit the project/Build.scala file and add the dependency. If you already have Play running, don’t forget to reload the project for the changes to be visible.

val appDependencies = Seq(
    "com.jayway.restassured" % "rest-assured" % "1.7" % "test"
)

The above example re-written to use REST-assured then looks like this:

import static play.test.Helpers.*;
import com.jayway.restassured.RestAssured;
...
@Test
public void testInServer() {
  running(testServer(3333), new Runnable() {
      public void run() {
         RestAssured.expect().statusCode(200).when().get("http://localhost:3333");
      }
  });
}

REST-assured defaults to localhost for requests, so it’s possible to cut down on the boilerplate and use relative URLs by tweaking the configuration a little.

import static play.test.Helpers.*;
import com.jayway.restassured.RestAssured;
...
private static final int PORT = 3333;

@Before
public void setUp()
{
    RestAssured.port = PORT;
}
...
@Test
public void testInServer() {
  running(testServer(PORT), new Runnable() {
      public void run() {
         RestAssured.expect().statusCode(200).when().get("/");
      }
  });
}

I’ve written a small example that’s available on github, and here’s a sample from it which features an entity being persisted, and then retrieved for testing

@Test
public void testGetBeer_present()
{
    running(testServer(PORT), new Runnable()
    {
        @Override
        public void run()
        {
            // Create the beer
            RestAssured.given()
                       .contentType(ContentType.JSON)
                       .content("{\"name\":\"Westmalle\"}")
                       .expect()
                       .statusCode(200)
                       .when()
                       .post("/");

            // Retrieve it by name, and bind the response body into a Beer instance
            Beer beer = RestAssured.expect()
                                   .statusCode(200)
                                   .when()
                                   .get("/Westmalle")
                                   .andReturn()
                                   .body()
                                   .as(Beer.class);
            Assert.assertEquals("Westmalle",
                                beer.name);
        }
    });
}

To run the tests, just start up Play in on your command line, and use the test command:

[play-rest-assured] $ test
[info] controllers.BeersTest
[info] + controllers.BeersTest.testGetAll_emptyDatabase
[info] + controllers.BeersTest.testGetAll_populatedDatabase
[info] + controllers.BeersTest.testGetBeer_emptyDatabase
[info] + controllers.BeersTest.testGetBeer_present
[info] + controllers.BeersTest.testUpdate
[info] 
[info] 
[info] Total for test controllers.BeersTest
[info] Finished in 6.954 seconds
[info] 5 tests, 0 failures, 0 errors
[info] Passed: : Total 5, Failed 0, Errors 0, Passed 5, Skipped 0
[success] Total time: 7 s, completed Oct 29, 2012 7:37:52 AM

Resources

• github: https://github.com/schaloner/play-2-examples/tree/master/play-rest-assured
• Example project: download