Test APIs
Before release your application to the public world, you have to make sure it works as expected.
Testing is the most effective way to prove your codes correct.

Test driven development

In the XP and Agile world, lots of developers are TDD advocate, and use it in daily work.
The basic flow of TDD can be summaries as:
  1. 1.
    Write a test first, then run test and get failure, failure info indicates what to do(You have not written any codes yet).
  2. 2.
    Code the implementation, and run test again and again, untill the test get passed.
  3. 3.
    Adjust the test to add more features, and refactor the codes, till all considerations are included.
But some developers prefer writing codes firstly and then write tests to verify them, it is OK. There is no policy to force you accept TDD. For a skilled developer, both are productive in work.
We have written some codes in the early posts, now it is time to add some test codes to show up how to test Spring components.
Spring provides a test context environment for developers, it supports JUnit and TestNG.
In this sample application, I will use JUnit as test runner, also use Mockito to test service in isolation, and use Rest Assured BDD like fluent APIs to test REST from client view.

A simple POJO test

A classic JUnit test could look like this.
public class PostTest {
public PostTest() {
}
@BeforeClass
public static void setUpClass() {
}
@AfterClass
public static void tearDownClass() {
}
private Post post;
@Before
public void setUp() {
post = new Post();
post.setTitle("test title");
post.setContent("test content");
}
@After
public void tearDown() {
post = null;
}
/**
* Test of getId method, of class Post.
*/
@Test
public void testPojo() {
assertEquals("test title", post.getTitle());
assertEquals("test content", post.getContent());
}
}
@BeforeClass and AfterClass method must be static, these will be executed after the test class is constructed and before it is destroyed.
@Before and @After will be executed around a test case.
A test case is a method annotated with @Test.
Another annotation we always used is @RunWith, such as @RunWith(SpringJUnit4ClassRunner.class), which will prepare specific test context for Spring tests.
Run the test in command line.
mvn test -Dtest=PostTest
You could see the following output summary for this test.
T E S T S
-------------------------------------------------------
Running com.hantsylabs.restexample.springmvc.domain.PostTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.015 sec - in com.hantsylabs.restexample.springmvc.domain.PostTest
Results :
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
Post is a simple POJO, does not depend on other dependencies.

Test Service

BlogService depends on PostRepository, but most of time, we only want to check if the business logic and flow correct in the BlogService and assume the dependency PostRepository are always working as expected. Thus it is easy to focus on testing BlogService itself.
Mockito provides the simplest approaches to mock the dependencies, and setup the assumption, and provides an isolation environment to test BlogService.

Isolate dependencies with Mockito

Mocks PostRepository, when invoke methods of PostRepository, return the dummy data we assumed. Mockito gives us a simple way to complete the assumption progress.
Create a MockDataConfig configuration class in test package.
@Configuration
public class MockDataConfig {
@Bean
public PostRepository postRepository() {
final Post post = createPost();
PostRepository posts = mock(PostRepository.class);
when(posts.save(any(Post.class))).thenAnswer((InvocationOnMock invocation) -> {
Object[] args = invocation.getArguments();
Post result = (Post) args[0];
result.setId(post.getId());
result.setTitle(post.getTitle());
result.setContent(post.getContent());
result.setCreatedDate(post.getCreatedDate());
return result;
});
when(posts.findOne(1000L)).thenThrow(new ResourceNotFoundException(1000L));
when(posts.findOne(1L)).thenReturn(post);
when(posts.findAll(any(Specification.class), any(Pageable.class))).thenReturn(new PageImpl(Arrays.asList(post), new PageRequest(0, 10), 1L));
when(posts.findAll()).thenReturn(Arrays.asList(post));
return posts;
}
@Bean
public CommentRepository commentRepository() {
return mock(CommentRepository.class);
}
@Bean
public BlogService blogService(PostRepository posts, CommentRepository comments){
return new BlogService(posts, comments);
}
@Bean
public Post createPost() {
Post post = new Post();
post.setCreatedDate(new Date());
post.setId(1L);
post.setTitle("First post");
post.setContent("Content of my first post!");
post.setCreatedDate(new Date());
return post;
}
}
We create mocked PostRepository in this configuration.
Create MockBlogServiceTest for BlogService, used MockDataConfig to load configurations.
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {MockDataConfig.class})
public class MockBlogServiceTest {
private static final Logger LOG = LoggerFactory.getLogger(MockBlogServiceTest.class);
@Inject
private PostRepository postRepository;
@Inject
private CommentRepository commentRepository;
}
PostRepository and CommentRepository are mocked object defined in the MockDataConfig.
Add a test method in MockBlogServiceTest.
@Test
public void testSavePost() {
PostForm form = new PostForm();
form.setTitle("saving title");
form.setContent("saving content");
PostDetails details = blogService.savePost(form);
LOG.debug("post details @" + details);
assertNotNull("saved post id should not be [email protected]", details.getId());
assertTrue(details.getId() == 1L);
//...
}
In the above test, asserts id value of the returned post is 1L.
Have a look at MockDataConfig, when calls save method of PostRepository and return a dummy post instance which id is 1L.
We can also test if the exception threw as expected in the MockDataConfig.
@Test(expected = ResourceNotFoundException.class)
public void testGetNoneExistingPost() {
blogService.findPostById(1000L);
}
Run the test in command line tools.
mvn test -Dtest=MockBlogServiceTest
You will see the test result like.
T E S T S
-------------------------------------------------------
Running com.hantsylabs.restexample.springmvc.test.MockBlogServiceTest
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.943 sec - in com.hantsylabs.restexample.springmvc.test.MockBlogServiceTest
Results :
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0

Integration test

We have known BlogService works when we mocked the dependencies.
Now we write a test to check if it works against a real database.
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {AppConfig.class, DataSourceConfig.class, DataJpaConfig.class, JpaConfig.class})
public class BlogServiceTest {
private static final Logger LOG = LoggerFactory.getLogger(BlogServiceTest.class);
@Inject
private PostRepository postRepository;
@Inject
private BlogService blogService;
private Post post;
public BlogServiceTest() {
}
@Before
public void setUp() {
postRepository.deleteAll();
post = postRepository.save(Fixtures.createPost("My first post", "content of my first post"));
assertNotNull(post.getId());
}
@After
public void tearDown() {
}
@Test
public void testSavePost() {
PostForm form = new PostForm();
form.setTitle("saving title");
form.setContent("saving content");
PostDetails details = blogService.savePost(form);
LOG.debug("post details @" + details);
assertNotNull("saved post id should not be [email protected]", details.getId());
assertNotNull(details.getId());
Page<PostDetails> allPosts = blogService.searchPostsByCriteria("", null, new PageRequest(0, 10));
assertTrue(allPosts.getTotalElements() == 2);
Page<PostDetails> posts = blogService.searchPostsByCriteria("first", Post.Status.DRAFT, new PageRequest(0, 10));
assertTrue(posts.getTotalPages() == 1);
assertTrue(!posts.getContent().isEmpty());
assertTrue(Objects.equals(posts.getContent().get(0).getId(), post.getId()));
PostForm updatingForm = new PostForm();
updatingForm.setTitle("updating title");
updatingForm.setContent("updating content");
PostDetails updatedDetails = blogService.updatePost(post.getId(), updatingForm);
assertNotNull(updatedDetails.getId());
assertTrue("updating title".equals(updatedDetails.getTitle()));
assertTrue("updating content".equals(updatedDetails.getContent()));
}
@Test(expected = ResourceNotFoundException.class)
public void testGetNoneExistingPost() {
blogService.findPostById(1000L);
}
}
In the @Before method, all Post data are cleared for each tests, and save a Post for further test assertion.
The above codes are similar with early Mockito version, the main difference is we have switched configuraitons to a real database. Check the @ContextConfiguration annotated on BlogServiceTest.
Run the test.
mvn test -Dtest=BlogServiceTest
The test result should be shown as below.
T E S T S
-------------------------------------------------------
Running com.hantsylabs.restexample.springmvc.test.BlogServiceTest
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 5.908 sec - in com.hantsylabs.restexample.springmvc.test.BlogServiceTest
Results :
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0

Test Controller

Spring provides a sort of mock APIs to emulate a Servlet container environment, thus it is possible to test MVC related feature without a real container.

Use MockMvc with mocked service

MockMvc does not need a Servlet container, but can test most of the Controller features.
Like the former MockBlogServiceTest, we can mock the controller's dependencies, thus is no need to load Spring configurations.
@RunWith(MockitoJUnitRunner.class)
public class MockPostControllerTest {
private static final Logger log = LoggerFactory.getLogger(MockPostControllerTest.class);
private MockMvc mvc;
ObjectMapper objectMapper = new ObjectMapper();
@Mock
private BlogService blogService;
@Mock
Pageable pageable = mock(PageRequest.class);
@InjectMocks
PostController postController;
@BeforeClass
public static void beforeClass() {
log.debug("==================before class=========================");
}
@AfterClass
public static void afterClass() {
log.debug("==================after class=========================");
}
@Before
public void setup() {
log.debug("==================before test case=========================");
Mockito.reset();
MockitoAnnotations.initMocks(this);
mvc = standaloneSetup(postController)
.setCustomArgumentResolvers(new PageableHandlerMethodArgumentResolver())
.setViewResolvers(new ViewResolver() {
@Override
public View resolveViewName(String viewName, Locale locale) throws Exception {
return new MappingJackson2JsonView();
}
})
.build();
}
@After
public void tearDown() {
log.debug("==================after test case=========================");
}
@Test
public void savePost() throws Exception {
PostForm post = Fixtures.createPostForm("First Post", "Content of my first post!");
when(blogService.savePost(any(PostForm.class))).thenAnswer(new Answer<PostDetails>() {
@Override
public PostDetails answer(InvocationOnMock invocation) throws Throwable {
PostForm fm = (PostForm) invocation.getArgumentAt(0, PostForm.class);
PostDetails result = new PostDetails();
result.setId(1L);
result.setTitle(fm.getTitle());
result.setContent(fm.getContent());
result.setCreatedDate(new Date());
return result;
}
});
mvc.perform(post("/api/posts").contentType(MediaType.APPLICATION_JSON).content(objectMapper.writeValueAsString(post)))
.andExpect(status().isCreated());
verify(blogService, times(1)).savePost(any(PostForm.class));
verifyNoMoreInteractions(blogService);
}
@Test
public void retrievePosts() throws Exception {
PostDetails post1 = new PostDetails();
post1.setId(1L);
post1.setTitle("First post");
post1.setContent("Content of first post");
post1.setCreatedDate(new Date());
PostDetails post2 = new PostDetails();
post2.setId(2L);
post2.setTitle("Second post");
post2.setContent("Content of second post");
post2.setCreatedDate(new Date());
when(blogService.searchPostsByCriteria(anyString(), any(Post.Status.class), any(Pageable.class)))
.thenReturn(new PageImpl(Arrays.asList(post1, post2), new PageRequest(0, 10, Direction.DESC, "createdDate"), 2));
MvcResult response = mvc.perform(get("/api/posts?q=test&page=0&size=10"))
.andExpect(status().isOk())
.andExpect(jsonPath("$.content[*].id", hasItem(1)))
.andExpect(jsonPath("$.content[*].title", hasItem("First post")))
.andReturn();
verify(blogService, times(1))
.searchPostsByCriteria(anyString(), any(Post.Status.class), any(Pageable.class));
verifyNoMoreInteractions(blogService);
log.debug("get posts result @" + response.getResponse().getContentAsString());
}
@Test
public void retrieveSinglePost() throws Exception {
PostDetails post1 = new PostDetails();
post1.setId(1L);
post1.setTitle("First post");
post1.setContent("Content of first post");
post1.setCreatedDate(new Date());
when(blogService.findPostById(1L)).thenReturn(post1);
mvc.perform(get("/api/posts/1").accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(content().contentType("application/json;charset=UTF-8"))
.andExpect(jsonPath("id").isNumber());
verify(blogService, times(1)).findPostById(1L);
verifyNoMoreInteractions(blogService);
}
@Test
public void removePost() throws Exception {
when(blogService.deletePostById(1L)).thenReturn(true);
mvc.perform(delete("/api/posts/{id}", 1L))
.andExpect(status().isNoContent());
verify(blogService, times(1)).deletePostById(1L);
verifyNoMoreInteractions(blogService);
}
@Test()
public void notFound() {
when(blogService.findPostById(1000L)).thenThrow(new ResourceNotFoundException(1000L));
try {
mvc.perform(get("/api/posts/1000").accept(MediaType.APPLICATION_JSON))
.andExpect(status().isNotFound());
} catch (Exception ex) {
log.debug("exception caught @" + ex);
}
}
}
In the setup method, mvc = standaloneSetup(postController) is trying to setup a MockMvc for controller. The test codes are easy to understand.

MockMvc with a real database

We changed a little on the above tests, replace the mocked service with the real configurations. Thus the tests will run against a real database, but still in mock mvc environment.
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {AppConfig.class, Jackson2ObjectMapperConfig.class, DataSourceConfig.class, JpaConfig.class, DataJpaConfig.class, WebConfig.class})
@WebAppConfiguration
public class PostControllerTest {
private static final Logger log = LoggerFactory.getLogger(PostControllerTest.class);
@Inject
WebApplicationContext wac;
@Inject
ObjectMapper objectMapper;
@Inject
private PostRepository postRepository;
private MockMvc mvc;
private Post post;
@BeforeClass
public static void beforeClass() {
log.debug("==================before class=========================");
}
@AfterClass
public static void afterClass() {
log.debug("==================after class=========================");
}
@Before
public void setup() {
log.debug("==================before test case=========================");
mvc = webAppContextSetup(this.wac).build();
postRepository.deleteAll();
post = postRepository.save(Fixtures.createPost("My first post", "content of my first post"));
}
@After
public void tearDown() {
log.debug("==================after test case=========================");
}
@Test
public void savePost() throws Exception {
PostForm post = Fixtures.createPostForm("First Post", "Content of my first post!");
mvc.perform(post("/api/posts").contentType(MediaType.APPLICATION_JSON).content(objectMapper.writeValueAsString(post)))
.andExpect(status().isCreated());
}
@Test
public void retrievePosts() throws Exception {
MvcResult response = mvc.perform(get("/api/posts?q=first&page=0&size=10"))
.andExpect(status().isOk())
.andExpect(jsonPath("$.content[0].id", is(post.getId().intValue())))
.andExpect(jsonPath("$.content[0].title", is("My first post")))
.andReturn();
log.debug("get posts result @" + response.getResponse().getContentAsString());
}
@Test
public void retrieveSinglePost() throws Exception {
mvc.perform(get("/api/posts/{id}", post.getId()).accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(content().contentType("application/json"))
.andExpect(jsonPath("$.id").isNumber())
.andExpect(jsonPath("$.title", is("My first post")));
}
@Test
public void removePost() throws Exception {
mvc.perform(delete("/api/posts/{id}", post.getId()))
.andExpect(status().isNoContent());
}
@Test()
public void notFound() {
try {
mvc.perform(get("/api/posts/1000").accept(MediaType.APPLICATION_JSON))
.andExpect(status().isNotFound());
} catch (Exception ex) {
log.debug("exception caught @" + ex);
}
}
}
In this test class, the Mockito codes are replaced with Spring test, and load the configurations defined in this project. It is close to the final production environment, except there is not a real Servlet container.

Test REST API as the client view

OK, now try to verify everything works in a real container.
@RunWith(BlockJUnit4ClassRunner.class)
public class IntegrationTest {
private static final Logger log = LoggerFactory.getLogger(IntegrationTest.class);
private static final String BASE_URL = "http://localhost:8080/angularjs-springmvc-sample/";
private RestTemplate template;
@BeforeClass
public static void init() {
log.debug("==================before class=========================");
}
@Before
public void beforeTestCase() {
log.debug("==================before test case=========================");
template = new BasicAuthRestTemplate("admin", "test123");
}
@After
public void afterTestCase() {
log.debug("==================after test case=========================");
}
@Test
public void testPostCrudOperations() throws Exception {
PostForm newPost = Fixtures.createPostForm("My first post", "content of my first post");
String postsUrl = BASE_URL + "api/posts";
ResponseEntity<Void> postResult = template.postForEntity(postsUrl, newPost, Void.class);
assertTrue(HttpStatus.CREATED.equals(postResult.getStatusCode()));
String createdPostUrl = postResult.getHeaders().getLocation().toString();
assertNotNull("created post url should be set", createdPostUrl);
ResponseEntity<Post> getPostResult = template.getForEntity(createdPostUrl, Post.class);
assertTrue(HttpStatus.OK.equals(getPostResult.getStatusCode()));
log.debug("post @" + getPostResult.getBody());
assertTrue(getPostResult.getBody().getTitle().equals(newPost.getTitle()));
ResponseEntity<Void> deleteResult = template.exchange(createdPostUrl, HttpMethod.DELETE, null, Void.class);
assertTrue(HttpStatus.NO_CONTENT.equals(deleteResult.getStatusCode()));
}
@Test
public void noneExistingPost() throws Exception {
String noneExistingPostUrl = BASE_URL + "api/posts/1000";
try {
template.getForEntity(noneExistingPostUrl, Post.class);
} catch (HttpClientErrorException e) {
assertTrue(HttpStatus.NOT_FOUND.equals(e.getStatusCode()));
}
}
}
RestTemplate is use for interaction with remote REST API, this test acts as a remote client, and shake hands with our backend through REST APIs.
BasicAuthRestTemplate is a helper class to process BASIC authentication.
public class BasicAuthRestTemplate extends RestTemplate {
public BasicAuthRestTemplate(String username, String password) {
addAuthentication(username, password);
}
private void addAuthentication(String username, String password) {
if (username == null) {
return;
}
List<ClientHttpRequestInterceptor> interceptors = Collections
.<ClientHttpRequestInterceptor>singletonList(
new BasicAuthorizationInterceptor(username, password));
setRequestFactory(new InterceptingClientHttpRequestFactory(getRequestFactory(),
interceptors));
}
private static class BasicAuthorizationInterceptor implements
ClientHttpRequestInterceptor {
private final String username;
private final String password;
public BasicAuthorizationInterceptor(String username, String password) {
this.username = username;
this.password = (password == null ? "" : password);
}
@Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body,
ClientHttpRequestExecution execution) throws IOException {
byte[] token = Base64.getEncoder().encode(
(this.username + ":" + this.password).getBytes());
request.getHeaders().add("Authorization", "Basic " + new String(token));
return execution.execute(request, body);
}
}
}
To run this test successfully, you have to configure maven-failsafe-plugin to set up a Servlet container.
  • Start up container before test is running
  • Shutdown the servlet container after the test is completed
    org.apache.maven.pluginsmaven-surefire-plugin2.19truetrue**/*IntegrationTest*
Excludes the IntegrationTest in the maven-surefire-plugin.
org.apache.maven.pluginsmaven-failsafe-plugin2.12.4**/*IntegrationTest*integration-testintegration-testverifyverify
Filter the IntegrationTest in the maven-failsafe-plugin. Here I configured jetty as Servlet container to run the test.
org.eclipse.jettyjetty-maven-plugin9.3.7.v20160115108005STOP/angularjs-springmvc-samplestart-jettypre-integration-teststopstart0truestop-jettypost-integration-teststop
In the pre-integration-test phase, check if the jetty is running and starts up it, in post-integration-test phase, shutdown the container.
Run the IntegrationTest in command line.
mvn clean verify
In the console, after all unit tess are done, it will start jetty and deploy the project war into jetty and run the IntegrationTest on it.
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 2.847 sec
Results :
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0
[WARNING] File encoding has not been set, using platform encoding Cp1252, i.e. build is platform dependent!
[INFO]
[INFO] --- jetty-maven-plugin:9.3.7.v20160115:stop (stop-jetty) @ angularjs-springmvc-sample ---
[INFO]
[INFO] --- maven-failsafe-plugin:2.12.4:verify (verify) @ angularjs-springmvc-sample ---
As you see in the console, after the test is done, it is trying to shutdown jetty.

Rest Assured

Rest Assured provides BDD like syntax, such as given, when, then, it is friendly for those familiar with BDD.
@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
@Slf4j
public class RestAssuredApplicationTest extends WebIntegrationTestBase {
@Before
public void beforeTest() {
super.setup();
RestAssured.port = port;
}
@Test
public void testDeletePostNotExisted() {
String location = "/api/posts/1000";
given()
.auth().basic(USER_NAME, PASSWORD)
.contentType(ContentType.JSON)
.when()
.delete(location)
.then()
.assertThat()
.statusCode(HttpStatus.SC_NOT_FOUND);
}
@Test
public void testGetPostNotExisted() {
String location = "/api/posts/1000";
given()
.auth().basic(USER_NAME, PASSWORD)
.contentType(ContentType.JSON)
.when()
.get(location)
.then()
.assertThat()
.statusCode(HttpStatus.SC_NOT_FOUND);
}
@Test
public void testPostFormInValid() {
PostForm form = new PostForm();
given()
.auth().basic(USER_NAME, PASSWORD)
.body(form)
.contentType(ContentType.JSON)
.when()
.post("/api/posts")
.then()
.assertThat()
.statusCode(HttpStatus.SC_BAD_REQUEST);
}
@Test
public void testPostCRUD() {
PostForm form = new PostForm();
form.setTitle("test title");
form.setContent("test content");
Response response = given()
.auth().basic(USER_NAME, PASSWORD)
.body(form)
.contentType(ContentType.JSON)
.when()
.post("/api/posts")
.then()
.assertThat()
.statusCode(HttpStatus.SC_CREATED)
.and()
.header("Location", containsString("/api/posts/"))
.extract().response();
String location = response.header("Location");
log.debug("header location value @" + location);
given().auth().basic(USER_NAME, PASSWORD)
.contentType(ContentType.JSON)
.when()
.get(location)
.then()
.assertThat()
.body("title", is("test title"))
.body("content", is("test content"));
PostForm updateForm = new PostForm();
updateForm.setTitle("test udpate title");
updateForm.setContent("test update content");
given()
.auth().basic(USER_NAME, PASSWORD)
.body(updateForm)
.contentType(ContentType.JSON)
.when()
.put(location)
.then()
.assertThat()
.statusCode(HttpStatus.SC_NO_CONTENT);
given().auth().basic(USER_NAME, PASSWORD)
.contentType(ContentType.JSON)
.when()
.get(location)
.then()
.assertThat()
.body("title", is("test udpate title"))
.body("content", is("test update content"));
given()
.auth().basic(USER_NAME, PASSWORD)
.contentType(ContentType.JSON)
.when()
.delete(location)
.then()
.assertThat()
.statusCode(HttpStatus.SC_NO_CONTENT);
given().auth().basic(USER_NAME, PASSWORD)
.contentType(ContentType.JSON)
.when()
.get(location)
.then()
.assertThat()
.statusCode(HttpStatus.SC_NOT_FOUND);
}
}
This test is also run as client, and interacts with backend via REST API.
The above Rest Assured sample codes are available in the Spring Boot version, check out the codes and experience yourself.
It also includes a simple JBehave sample, if you are a JBehave user, you maybe interested in it.

Source Code

Check out sample codes from my github account.
git clone https://github.com/hantsy/angularjs-springmvc-sample
Or the Spring Boot version:
git clone https://github.com/hantsy/angularjs-springmvc-sample-boot
Read the live version of these posts from Gitbook:Building RESTful APIs with Spring MVC.