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WebApplicationContext is required - MockMVC

I'm trying to unit test a controller class, but have been stuck with the following error. I tried changing notations and following some online tutorials but it has not been working, I always get this same error.
Here's the stackTrace:
java.lang.IllegalArgumentException: WebApplicationContext is required
at org.springframework.util.Assert.notNull(Assert.java:201)
at org.springframework.test.web.servlet.setup.DefaultMockMvcBuilder.<init>(DefaultMockMvcBuilder.java:52)
at org.springframework.test.web.servlet.setup.MockMvcBuilders.webAppContextSetup(MockMvcBuilders.java:51)
at br.com.gwcloud.smartplace.catalog.controller.test.ItemControllerTest.setUp(ItemControllerTest.java:66)
...
And this is my controller test class:
#SpringBootTest
#WebMvcTest(controllers = ItemController.class)
#ActiveProfiles("test")
#WebAppConfiguration
public class ItemControllerTest {
#MockBean
private ItemRepository ir;
#Autowired
private MockMvc mockMvc;
#Autowired
private ModelMapper modelMapper;
#Autowired
private WebApplicationContext webApplicationContext;
#Autowired
private ObjectMapper objectMapper;
#Before
public void setUp() {
this.mockMvc = webAppContextSetup(webApplicationContext).build();
DefaultMockMvcBuilder builder = MockMvcBuilders.webAppContextSetup(this.webApplicationContext);
this.mockMvc = builder.build();
}
#Test
public void shouldCreateNewItem() throws Exception {
ItemDTO itemDTO = new ItemDTO();
itemDTO.setName("Leo");
itemDTO.setDescription("abc description");
itemDTO.setEnabled(true);
itemDTO.setPartNumber("leo123");
Item item = itemDTO.convertToEntity(modelMapper);
mockMvc.perform(
post("/api/item/").contentType(
MediaType.APPLICATION_JSON).content(objectMapper.writeValueAsString(item))).andExpect(
status().isOk());
}
}

The error you are encountering might be solved by adding:
#RunWith(SpringRunner.class)
Just below #SpringBootTest. Or you could instead extend AbstractJUnit4SpringContextTests.
Another problem is that the WebApplicationContext might not be available in an #Before annotated method. Try moving it into the test method itself.
That said, I usually avoid unit testing controllers, since I don't put any business logic in them. The stuff controllers do is specifying paths, mapping request arguments, error handling (although that is better handled in a separate ControllerAdvice class), setting up the view model and view target etc. These are all what I call 'plumbing' and tie in heavily with the framework you are using. I don't unit test that.
Instead, this plumbing can be validated by having a couple of high level integration tests that actually do a remote call to the controller and execute a complete flow, including all the plumbing.
Any business logic should be taken outside of the controller (typically in services) and unit tested there, in isolation.

Have you tried removing #SpringBootTest and #WebAppConfiguration. If you are only interested in testing controller you don't need a full-blown application through these annotations.

Spring Boot integration test MockBean zero interactions

We have a quite big suite of tests (integration/unit/cucumber....).
Now we want to add an additional integration test using the following code:
#ExtendWith(SpringExtension.class)
#SpringBootTest
#ActiveProfiles("integrationTest")
#AutoConfigureMockMvc
class MyIntegrationTest {
#Autowired
private MockMvc mockMvc;
#MockBean
private MyRepository myRepository;
#Test
void myTest() throws Exception {
final var argument = ArgumentCaptor.forClass(MyEntity.class);
mockMvc.perform(
post(ENDPOINT)
.contentType(MediaType.APPLICATION_JSON)
.accept(MediaType.APPLICATION_JSON)
.content("{}")
.secure(true))
.andExpect(status().isOk())
.andReturn().getResponse().getContentAsString();
verify(myRepository).saveAndFlush(argument.capture());
final var payload = argument.getValue().getRequest();
assertThat(payload).doesNotContainAnyWhitespaces();
}
This is MyRepository definition
#Repository
public interface RiskScoreRepository extends JpaRepository<..> {}
If I run this test only there are no issues. As soon as I run mvn verify I get the following error:
Wanted but not invoked:
myRepository bean.saveAndFlush(
<Capturing argument>
);
-> at MyIntegrationTest.registrationWorksThroughAllLayers(MyIntegrationTest.java:XX)
Actually, there were zero interactions with this mock.
I assume that this is because the Application context is already loaded by a previous integration test.
How can I solve this problem?
EDIT
I tried to disable all the others integrations tests and now MyIntegrationTest is passing even with mvn verify
How can solve this?
Thanks

#WebMvcTest creating more than one Controller for some reason

I'm trying to create a controller test with #WebMvcTest, and as I understand, when I put #WebMvcTest(ClientController.class) annotation of the test class it should not create a whole lot of beans, but just ones that this controller requires.
I'm mocking the bean this controller requires with #MockBean, but somehow it fails with an exception that there's 'No qualifying bean' of another service that does not required by this controller but by another.
So this test is failing:
#RunWith(SpringRunner.class)
#WebMvcTest(controllers = ClientController.class)
public class ClientControllerTest {
#MockBean
ClientService clientService;
#Test
public void getClient() {
assertEquals(1,1);
}
}
I've created an empty Spring Boot project of the same version (2.0.1) and tried to create test over there. It worked perfectly.
So my problem might be because of the dependencies that my project has many, but maybe there's some common practice where to look in this situation? What can mess #WebMvcTest logic?

I've found a workaround. Not to use #WebMvcTest and #MockBean, but to create everything by hand:
//#WebMvcTest(ClientController.class)
#RunWith(SpringRunner.class)
public class ClientControllerTest {
private MockMvc mockMvc;
#Mock
ClientService clientService;
#Before
public void setUp() {
mockMvc = MockMvcBuilders.standaloneSetup(
new ClientController(clientService)
).build();
}
works with Spring 1.4.X and with Spring Boot 2.X (had different exception there and there), but still doesn't explain why #WebMvcTest doesn't work

Testing a custom RepositoryRestController that uses a PersistentEntityResourceAssembler

I have a RepositoryRestController that exposes resources for some persistent entities.
I have a method on my controller that takes a PersistentEntityResourceAssembler to help me generate the resources automatically.
#RepositoryRestController
#ExposesResourceFor(Customer.class)
#RequestMapping("/api/customers")
public class CustomerController {
#Autowired
private CustomerService service;
#RequestMapping(method = GET, value="current")
public ResponseEntity getCurrent(Principal principal Long id, PersistentEntityResourceAssembler assembler) {
return ResponseEntity.ok(assembler.toResource(service.getForPrincipal(principal)));
}
}
(Contrived example, but it saves going into too much detail about irrelevant details of my use-case)
I'd like to write a test for my controller (my real use-case is actually worth testing), and am planning on making use of #WebMvcTest.
So I have the following test class:
#RunWith(SpringRunner.class)
#WebMvcTest(CustomerController.class)
#AutoConfigureMockMvc(secure=false)
public class CustomerControllerTest {
#Autowired
private MockMvc client;
#MockBean
private CustomerService service;
#Test
public void testSomething() {
// test stuff in here
}
#Configuration
#Import(CustomerController.class)
static class Config {
}
}
But I get an exception saying java.lang.NoSuchMethodException: org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler.<init>()
Presumably something is not being configured correctly here because I'm missing the entire data layer. Is there some way of mocking out the PersistentEntityResourceAssembler? Or another approach I could use here?

I ended up for now with:
#RunWith(SpringRunner.class)
#SpringBootTest
#AutoConfigureMockMvc
The downsite of it is that the test would start the full Spring application context (but without the server).

I ended up doing a slightly hacky solution here:
I removed PersistentEntityResourceAssembler from the controller method.
I added an #Autowired RepositoryEntityLinks to the controller, on which I call linkToSingleResource to create the links as needed.
I added an #MockBean RepositoryEntityLinks to my test class, and configured the mocking to return something sensible:
given(repositoryEntityLinks.linkToSingleResource(any(Identifiable.class)))
.willAnswer(invocation -> {
final Identifiable identifiable = (Identifiable) invocation.getArguments()[0];
return new Link("/data/entity/" + identifiable.getId().toString());
});
It's far from ideal - I'd love to know if there's a way of getting just enough of the data layer up that I can depend on PersistentEntityResourceAssembler.

How to mock remote REST API in unit test with Spring?

Assume I have made a simple client in my application that uses a remote web service that is exposing a RESTful API at some URI /foo/bar/{baz}. Now I wish to unit test my client that makes calls to this web service.
Ideally, in my tests, I’d like to mock the responses I get from the web service, given a specific request like /foo/bar/123 or /foo/bar/42. My client assumes the API is actually running somewhere, so I need a local "web service" to start running on http://localhost:9090/foo/bar for my tests.
I want my unit tests to be self-contained, similar to testing Spring controllers with the Spring MVC Test framework.
Some pseudo-code for a simple client, fetching numbers from the remote API:
// Initialization logic involving setting up mocking of remote API at
// http://localhost:9090/foo/bar
#Autowired
NumberClient numberClient // calls the API at http://localhost:9090/foo/bar
#Test
public void getNumber42() {
onRequest(mockAPI.get("/foo/bar/42")).thenRespond("{ \"number\" : 42 }");
assertEquals(42, numberClient.getNumber(42));
}
// ..
What are my alternatives using Spring?

Best method is to use WireMock.
Add the following dependencies:
<dependency>
<groupId>com.github.tomakehurst</groupId>
<artifactId>wiremock</artifactId>
<version>2.4.1</version>
</dependency>
<dependency>
<groupId>org.igniterealtime.smack</groupId>
<artifactId>smack-core</artifactId>
<version>4.0.6</version>
</dependency>
Define and use the wiremock as shown below
#Rule
public WireMockRule wireMockRule = new WireMockRule(8089);
String response ="Hello world";
StubMapping responseValid = stubFor(get(urlEqualTo(url)).withHeader("Content-Type", equalTo("application/json"))
.willReturn(aResponse().withStatus(200)
.withHeader("Content-Type", "application/json").withBody(response)));

If you use Spring RestTemplate you can use MockRestServiceServer. An example can be found here REST Client Testing With MockRestServiceServer.

If you want to unit test your client, then you'd mock out the services that are making the REST API calls, i.e. with mockito - I assume you do have a service that is making those API calls for you, right?
If on the other hand you want to "mock out" the rest APIs in that there is some sort of server giving you responses, which would be more in line of integration testing, you could try one of the many framework out there like restito, rest-driver or betamax.

You can easily use Mockito to mock a REST API in Spring Boot.
Put a stubbed controller in your test tree:
#RestController
public class OtherApiHooks {
#PostMapping("/v1/something/{myUUID}")
public ResponseEntity<Void> handlePost(#PathVariable("myUUID") UUID myUUID ) {
assert (false); // this function is meant to be mocked, not called
return new ResponseEntity<Void>(HttpStatus.NOT_IMPLEMENTED);
}
}
Your client will need to call the API on localhost when running tests. This could be configured in src/test/resources/application.properties. If the test is using RANDOM_PORT, your client under test will need to find that value. This is a bit tricky, but the issue is addressed here: Spring Boot - How to get the running port
Configure your test class to use a WebEnvironment (a running server) and now your test can use Mockito in the standard way, returning ResponseEntity objects as needed:
#RunWith(SpringRunner.class)
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class TestsWithMockedRestDependencies {
#MockBean private OtherApiHooks otherApiHooks;
#Test public void test1() {
Mockito.doReturn(new ResponseEntity<Void>(HttpStatus.ACCEPTED))
.when(otherApiHooks).handlePost(any());
clientFunctionUnderTest(UUID.randomUUID()); // calls REST API internally
Mockito.verify(otherApiHooks).handlePost(eq(id));
}
}
You can also use this for end-to-end testing of your entire microservice in an environment with the mock created above. One way to do this is to inject TestRestTemplate into your test class, and use that to call your REST API in place of clientFunctionUnderTest from the example.
#Autowired private TestRestTemplate restTemplate;
#LocalServerPort private int localPort; // you're gonna need this too
How this works
Because OtherApiHooks is a #RestController in the test tree, Spring Boot will automatically establish the specified REST service when running the SpringBootTest.WebEnvironment.
Mockito is used here to mock the controller class -- not the service as a whole. Therefore, there will be some server-side processing managed by Spring Boot before the mock is hit. This may include such things as deserializing (and validating) the path UUID shown in the example.
From what I can tell, this approach is robust for parallel test runs with IntelliJ and Maven.

What you are looking for is the support for Client-side REST Tests in the Spring MVC Test Framework.
Assuming your NumberClient uses Spring's RestTemplate, this aforementioned support is the way to go!
Hope this helps,
Sam

Here is a basic example on how to mock a Controller class with Mockito:
The Controller class:
#RestController
#RequestMapping("/users")
public class UsersController {
#Autowired
private UserService userService;
public Page<UserCollectionItemDto> getUsers(Pageable pageable) {
Page<UserProfile> page = userService.getAllUsers(pageable);
List<UserCollectionItemDto> items = mapper.asUserCollectionItems(page.getContent());
return new PageImpl<UserCollectionItemDto>(items, pageable, page.getTotalElements());
}
}
Configure the beans:
#Configuration
public class UserConfig {
#Bean
public UsersController usersController() {
return new UsersController();
}
#Bean
public UserService userService() {
return Mockito.mock(UserService.class);
}
}
The UserCollectionItemDto is a simple POJO and it represents what the API consumer sends to the server. The UserProfile is the main object used in the service layer (by the UserService class). This behaviour also implements the DTO pattern.
Finally, mockup the expected behaviour:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(loader = AnnotationConfigContextLoader.class)
#Import(UserConfig.class)
public class UsersControllerTest {
#Autowired
private UsersController usersController;
#Autowired
private UserService userService;
#Test
public void getAllUsers() {
initGetAllUsersRules();
PageRequest pageable = new PageRequest(0, 10);
Page<UserDto> page = usersController.getUsers(pageable);
assertTrue(page.getNumberOfElements() == 1);
}
private void initGetAllUsersRules() {
Page<UserProfile> page = initPage();
when(userService.getAllUsers(any(Pageable.class))).thenReturn(page);
}
private Page<UserProfile> initPage() {
PageRequest pageRequest = new PageRequest(0, 10);
PageImpl<UserProfile> page = new PageImpl<>(getUsersList(), pageRequest, 1);
return page;
}
private List<UserProfile> getUsersList() {
UserProfile userProfile = new UserProfile();
List<UserProfile> userProfiles = new ArrayList<>();
userProfiles.add(userProfile);
return userProfiles;
}
}
The idea is to use the pure Controller bean and mockup its members. In this example, we mocked the UserService.getUsers() object to contain a user and then validated whether the Controller would return the right number of users.
With the same logic you can test the Service and other levels of your application. This example uses the Controller-Service-Repository Pattern as well :)