Rest-assured is a 100% java-based, BDD style, test library that you can use for testing REST api's in java projects. These are the slides from the presentation and demo I give at the 2017 #JBCNConf Java conference in Barcelona.

1. Test your microservices with
buzzword services

2. Introduction
www.craftsmen.nl
michel@craftsmen.nl

4. Contents
• Rest testing Context
• Rest-Assured
Introduction
Demo
Other features
• Integration with Spring / SpringBoot
Mocking dependencies
• Wrapup
• Q&A

5. Who here...
...is developing (micro/ buzzword) services?
...is working with REST interfaces on a daily basis?
...uses automated testing for their REST interfaces?

6. What is REST testing?
Component test against the REST boundary of your service
Conference
service
REST api
GET /conference/1 { “name” : “JBCNConf2017”,
“Description”: “best Java conference in
the world!”
“begins”: “19-06-2017”
“ends”: “21-06-2017”
“city”: “Barcelona”
}
Test framework

7. Types of tests
Out-of-process tests
Tests against your deployed artifact
In-process tests
Tests against your artifact in-memory
Contract tests
Out-of-process tests against someone else’s api
(either deployed or stubbed)
Test framework
Conference
service memdb
In-memory call
Test framework
Conference
service db
network url
network
Test framework
Other service

8. Testing REST api’s Using SoapUI
Postman
By Hand

9. Testing REST api’s with
Scenario: Conference service should return JBCNConf Conference
Given a running conference service
When request conference “1”
Then it should return a conference
And the attribute "name" should be "JBCNConf2017"
Feature
file
Glue
code +
httpclient
Conference
service
R
E
S
T

10. Testing REST api’s with
private RestInterface restInterface;
@When("request conference d")
public void requestConference(int id) {
Map<String,String> map = new HashMap<>();
map.put("id", String.valueOf(id));
restInterface.setURIParameters(map);
restInterface.callRestService();
}
@Then("it should return a conference")
public void thenConferenceIsReturned() {
assertEquals(200, restInterface.getStatusCode());
}
@And("the attribute s should be s")
public void theAttributeShouldBe(String name, String value) {
String json = restInterface.getJSON();
//parsing and asserting stuff
}

11. Enter
• Developed and maintained by Johan Haleby (launched dec 2010)
• Rest-testing in a JUnit fashion
• 100% Java DSL api (Groovy underneath)
• Uses GPath for simplifying asserts, making testing just as easy like in Groovy!
• Focuses on testing with a concise, BDD-like syntax
• Really helped us to reduce boilerplate and write readable tests very quickly!

12. Getting started
<dependency>
<groupId>io.rest-assured</groupId>
<artifactId>rest-assured</artifactId>
<version>3.0.3</version>
<scope>test</scope>
</dependency>
testCompile 'io.rest-assured:rest-assured:3.0.3'

13. import static io.restassured.RestAssured.*;
@Test
public void restServiceShouldProduceResponse() {
given().
…. Setting up request, params, headers, cookies, auth…
when().
.... calling a URL through GET, POST, etc…
then().
...assert a bunch of stuff
}
Writing a test

15. Back to our conference service
import static io.restassured.RestAssured.when;
import static org.hamcrest.CoreMatchers.equalTo;
import org.junit.Test;
public class ConferenceRestIT {
@Test
public void test() {
given().
when().
get("/conference/{id}", 1).
then().
statusCode(200).
body("name", equalTo("JBCNConf2017"));
}
}

16. Parameters
given()
.queryParam("param1", "value")
.when()
.get("/conference")
.then()
.statusCode(200);
given()
.formParam("param1", "value")
.when()
.post("/conference")
.then()
.statusCode(200);
You can force
RestAssured to use the
parameter type

17. Parameters
given()
.param("param1", "value")
.when()
.get("/conference")
.then()
.statusCode(200);
given()
.param("param1", "value")
.when()
.post("/conference")
.then()
.statusCode(200);
QueryParam
FormParam
RestAssured will automatically choose the correct param type

18. Multi-value Parameters
given()
.param("param1", Arrays.asList("value1", “value2”)
.when()
.get("/conference")
.then()
.statusCode(200);

19. Path Parameters
given().
pathParam("conferenceId", "JBCNConf2017").
when().
post("/conference/{conferenceId}/{speakerId}", 23).
then().
You can mix named and unnamed params

20. Posting a new conference
@Test
public void testAddConference() throws JSONException {
String body = new JSONObject()
.put("name", " Devoxx") //
.put("description", "also pretty cool conference") //
.put("begins", LocalDate.now().format(DateTimeFormatter.ofPattern("dd-MM-yyyy"))) //
.put("ends", LocalDate.now().format(DateTimeFormatter.ofPattern("dd-MM-yyyy"))) //
.put("city", "Barcelona") //
.toString();
given()
.body(body) //
.contentType(ContentType.JSON) //
.when() //
.post("/conference") //
.then() //
.statusCode(200);
}
Note: you have to handle transaction rollback yourself!

21. Posting with object
@Test
public void testAddConferenceWithObject() {
Conference conference = new Conference();
conference.setName("Devoxx");
conference.setDescription("pretty cool,too!");
conference.setBegins(LocalDate.parse("2017-11-06").now());
conference.setEnds(LocalDate.parse("2017-11-10"));
conference.setCity("Antwerp");
given()
.body(conference)
.contentType(ContentType.JSON)
.when()
.post("/conference")
.then()
.statusCode(200);
}

22. Verifying the response
given().
contentType("application/json").
when().
get("/conference") //
.then() //
.statusCode(200) //
.body("findAll{it.name.startsWith('J')}.name", hasItems("JBCNConf2017"),
"name[0]", equalTo("JBCNConf2017"));

23. Logging
given().
log().all().
when().
get("/conference/{id}", 1).
then().
log().ifValidationFails().
statusCode(200).
body("name", equalTo("JBCNConf2017"));

24. JsonPath expressions
● Get /conference/1
○ name -> “JBCNConf0217”
Assume 2 conferences
● Get /conference
○ name-> [“JBCNConf2017”, “Devoxx”]
○ name[0] -> “JBCNConf2017”

25. Headers
given()
.header("Content-type", "text/html")
.when()
.get("/conference")
.then()
.header("Content-type", "application/json")
Also, support for multi-value headers
.headers(“myheader”, “value1”, “value2”)

26. Basic authentication
given()
.auth()
.basic("admin", "admin")
when().
get("/conference") //
.then() //
.statusCode(200) //

27. Cookies
given()
.cookie("mycookie", "mycookievalue")
.when()
.get("/conference")
.then()
.cookie("mycookie", "mycookievalue")
Also, support for multi-value cookies
.cookies(“mycookie”, “value1”, “value2”)

28. Response time
.when()
.get("/conference")
.then()
.time(lessThan(2L), SECONDS);

29. Extracting data
@Test
public void extractJBCNConference() {
String response = when()
.get("/conference/{id}", 1)
.then()
.extract()
.asString();
System.out.println(response);
}
You can extracts response, paths, cookies, headers etc.

30. Reusing request and response setups
RequestSpecBuilder requestSpecBuilder = new RequestSpecBuilder();
requestSpecBuilder.setContentType("application/json");
ResponseSpecBuilder responseSpecBuilder = new ResponseSpecBuilder();
responseSpecBuilder.expectStatusCode(200);
given().
spec(requestSpecBuilder.build()).
when().
get("/conference").
then().
spec(responseSpecBuilder.build());
You can merge specs and arbitrary params /
headers / cookies etc.

32. Other authentication methods
● Form authentication
● OAuth1
● OAuth2
● Custom authentication

33. Form authentication
given()
.auth()
.form(“admin”, “admin”, new FormAuthConfig("/j_spring_security_check", "j_username", "j_password"
))
when().
get("/conference") //
.then() //
.statusCode(200) //

34. Form authentication, Spring shortcut
given()
.auth()
.form(“admin”, “admin”, FormAuthConfig.springSecurity())
when().
get("/conference") //
.then() //
.statusCode(200) //

35. Cookies
given()
.cookie("mycookie", "mycookievalue")
.when()
.get("/conference")
.then()
.cookie("mycookie", "mycookievalue")
Also, support for multi-value cookies
.cookies(“mycookie”, “value1”, “value2”)

36. JSON schema validation
when()
.get("/conference")
.then()
.assertThat()
.body(matchesJsonSchemaInClasspath("conference.json"));
You can check against a valid json schema:
Only use this to test your own service

37. Testing multipart upload
given().
multiPart("file", new File(getClass().getResource("/file.txt").toURI())).
when().
post("/upload").
then()
.assertThat().body(equalTo("succeeded!"));

38. Session support
SessionFilter sessionFilter = new SessionFilter();
given().
auth().form("John", "Doe").
filter(sessionFilter).
when().
get("/formAuth").
then().
statusCode(200);
given().
filter(sessionFilter). when().
get("/x").
then().
statusCode(200);

39. given().
proxy(host("http://myhost.org").
withAuth("username", "password")).
then()...
RestAssured.proxy("localhost", 8888);
RequestSpecification specification = new RequestSpecBuilder()
.setProxy("localhost")
.build();
Proxy support

40. Defaults
Rest-assured goes to localhost, port 8080
You can change this behaviour:
given.port(80).when(....
RestAssured.port = 80;
With a Request spec builder
Same goes for host, baseURI, basePath, etc…
Easy to make this flexible by system property
given.port(System.getProperty(“server.port”)).when(...

41. Integration with

42. Integration with Spring
● Just use a @SpringBootTest IT test
● It will spin up a SpringBoot app
● Out-of-process testing, so just use RestAssured as you would
normally do
@SpringBootTest
SpringBoot Conference
service db
network url
network

43. Integration with traditional Spring application
● Use a normal Spring IT test
● Since this is in-process, you need to connect to the Dispatcher in some way
● Use the RestAssuredMockMvc class instead of RestAssured
● Wrapper around Spring MockMvc testing framework
● Slightly different programming model, however...
SpringIT test
SpringApp memdb
In-memory call
JVM

44. Mocking dependencies
Your service depends on some other service
ConferenceService
SpeakerService
TestFramework
SpeakerServiceMock
Mock out dependencies during testing

45. Spring Boot example
@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
@TestPropertySource("classpath:test.properties")
public class SpringBootRestIT {
@LocalServerPort
private int randomServerPort;
@Test
public void testJBCNConference() {
given().
port(randomServerPort).
log().all().
when().
get("/conference/{id}", 1).
then().
statusCode(200).
}

46. Traditional Spring example
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {ConferenceApplication.class})
@WebAppConfiguration
public class TraditionalSpringIT {
@Autowired
private WebApplicationContext context;
@Before
public void
rest_assured_is_initialized_with_the_web_application_context_before_each_test() {
RestAssuredMockMvc.webAppContextSetup(context);
}
@After
public void
rest_assured_is_reset_after_each_test() {
RestAssuredMockMvc.reset();
}
@Test
public void testJBCNConference() {
RestAssuredMockMvc.when().
get("/conference/{id}", 1).
then().
statusCode(200).
body("name", equalTo("JBCNConf2017"));
}

47. Using WireMock
private WireMockServer wireMockServer;
@Before
public void setup() {
startWireMockServer();
wireMockServer.stubFor(get(anyUrl()).willReturn(buildResponse()));
}
private ResponseDefinitionBuilder buildResponse() {
return responseDefinitionBuilder;
}
private void startWireMockServer() {
URI uri = URI.create(speakerEndpoint);
wireMockServer = new WireMockServer(options().port(8081));
wireMockServer.start();
}
@After
public void tearDown() {
wireMockServer.stop();
}

48. Rest-assured
+
Rest
==
Love

49. Pros and cons
● Writing a REST test takes minutes
● Really easy to read
● Flexible programming model (json/xml agnostic, free chaining of methods)
● Works well in-process (Spring IT) and out-of-process (SpringBoot)
● (Relatively) fast feedback
Contract testing
● You could use RestAssured for that, but you need a running instance
● Pact / Spring Cloud Contract are better solutions
Improvements
● If only someone could write a good code formatter….

50. http://rest-assured.io/
https://github.com/MichelSchudel/restassured-demo
michel@craftsmen.nl