Is it possible to test Spring REST Controllers without #DirtiesContext? - java

I'm working on a Spring-Boot web application. The usual way of writing integration tests is:
#Test
#Transactional
#Rollback(true)
public void myTest() {
// ...
}
This works nicely as long as only one thread does the work. #Rollback cannot work if there are multiple threads.
However, when testing a #RestController class using the Spring REST templates, there are always multiple threads (by design):
the test thread which acts as the client and runs the REST template
the server thread which receives and processes the request
So you can't use #Rollback in a REST test. The question is: what do you use instead to make tests repeatable and have them play nicely in a test suite?
#DirtiesContext works, but is a bad option because restarting the Spring application context after each REST test method makes the suite really slow to execute; each test takes a couple of milliseconds to run, but restarting the context takes several seconds.

First of all, testing a controller using a Spring context is no unit test. You should consider writing a unit test for the controller by using mocks for the dependencies and creating a standalone mock MVC:
public class MyControllerTest {
#InjectMocks
private MyController tested;
// add #Mock annotated members for all dependencies used by the controller here
private MockMvc mvc;
// add your tests here using mvc.perform()
#Test
public void getHealthReturnsStatusAsJson() throws Exception {
mvc.perform(get("/health"))
.andExpect(status().isOk())
.andExpect(content().contentTypeCompatibleWith(MediaType.APPLICATION_JSON))
.andExpect(jsonPath("$.status", is("OK")));
}
#Before
public void createControllerWithMocks() {
MockitoAnnotations.initMocks(this);
MockMvcBuilders.standaloneSetup(controller).build()
}
}
This even works if you use an external #ControllerAdvice for error handling etc by simply calling setControllerAdvice() on the MVC builder.
Such a test has no problems running in parallel and is much faster by no need to setup a Spring context at all.
The partial integration test you described is also useful to make sure the right wiring is used and all tested units work together as expected. But I would more go for a more general integration test including multiple/all endpoints checking if they work in general (not checking the edge cases) and mocking only services reaching out to external (like internal REST clients, replacing the database by one in memory, ...). With this setup you start with a fresh database and maybe will not even need to rollback any transaction. This is of course most comfortable using a database migration framework like Liquibase which would setup your in memory db on the fly.

Below is my implement followed by #4
private MockMvc mockMvc;
#Mock
private LoginService loginService;
#Mock
private PersonalService personalService;
#InjectMocks
private LoginController loginController;
#BeforeEach
public void setUp() {
MockitoAnnotations.openMocks(this);
mockMvc = MockMvcBuilders.standaloneSetup(loginController).build();
}
#Test
void simple_login() throws Exception {
Mockito.when(loginService.login(Mockito.anyString(), Mockito.anyString()))
.thenReturn(UserAccessData.builder()
.accessToken("access_token_content")
.refreshToken("refresh_token_count")
.build());
mockMvc.perform(
MockMvcRequestBuilders.post("/login/simple")
.contentType(MediaType.APPLICATION_JSON_VALUE)
.param("accountName", "1234561")
.param("password", "e10adc3949ba59abbe56e057f20f883e")
)
.andDo(print())
.andExpect(MockMvcResultMatchers.status().isOk())
.andExpect(jsonPath("$.tokens.accessToken", is("access_token_content")))
.andExpect(jsonPath("$.tokens.refreshToken", is("refresh_token_count")))
;
}

Related

How can I persist entities during a SpringBootTest integration test

I am writing an integration test for a SpringBoot 2 RestController. I want to test 404 behaviour and creation of entities. However, when I try to create entities and persist them before or during a test, they are not persisted in the SpringBoot context. By that I mean they are visible in the test context (during debugging of the test) but not for the Controller (ie it does not find them and my tests fail). What am I doing wrong?
How can I persist entities and flush the context during a test so that code that is called during an integration test sees them? I don't want to use a #before annotation to populate a database because I want to do it in my #test methods.
Here is my code. Thanks
#RunWith(SpringRunner.class)
#Transactional
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class InvoiceControlllerIT extends GenericControllerIT {
#Autowired
EntityManager entityManager;
#Test
#Transactional
public void cascadesChildEntityAssociationOnCreate() throws IOException {
assertThat(invoicerRepository.count(), equalTo(0L));
assertThat(invoiceRepository.count(), equalTo(0L));
assertThat(invoiceeRepository.count(), equalTo(0L));
// create an invoicee
Invoicee savedInvoicee = invoiceeRepository.save(new Invoicee());
assertThat(invoiceeRepository.count(), equalTo(1L));
// create an invoicer
Invoicer savedInvoicer = invoicerRepository.save(new Invoicer());
assertThat(invoicerRepository.count(), equalTo(1L));
// THIS IS THE PROBLEM, FLUSHING DURING THE TEST DOES NOT EFFECT THE CONTROLLERS ABILITY TO SEE THE NEWLY CREATED ENTITIES
entityManager.flush();
// create input
InvoiceInputDto inputDto = InvoiceInputDto
.builder()
.invoicee(savedInvoicee.getId())
.invoicer(savedInvoicer.getId())
.name("test-name")
.build();
// make call
ResponseEntity<InvoiceDto> response = template.postForEntity(url("/invoices", TOKEN), inputDto, InvoiceDto.class);
assertThat(response.getStatusCode(), equalTo(HttpStatus.CREATED));
assertThat(response.getBody().getName(), equalTo(inputDto.getName()));
// check associations
assertThat(invoiceeRepository.findById(savedInvoicee.getId()).get().getInvoices(), hasSize(1));
}
}
According to the docs:
If your test is #Transactional, it rolls back the transaction at the
end of each test method by default. However, as using this arrangement
with either RANDOM_PORT or DEFINED_PORT implicitly provides a real
servlet environment, the HTTP client and server run in separate
threads and, thus, in separate transactions. Any transaction initiated
on the server does not roll back in this case
(source: https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-testing.html#boot-features-testing-spring-boot-applications)
Since the test transaction is separate from the HTTP server transaction, the controller won't see changes made from within the test method until the test transaction is actually committed. Conversely, you won't be able to roll back changes made as a result to the server call.
You will seriously make your life easier by providing a mock implementation for whatever service/repository your controller uses. Alternatively, you could use a tool like DBUnit to setup and tear down the database around each test case.
This worked for me:
#Inject
private EntityManagerFactory entityManagerFactory;
#BeforeEach
void setUp() {
EntityManager entityManager = entityManagerFactory.createEntityManager();
entityManager.getTransaction().begin();
entityManager.persist(someEntity());
entityManager.getTransaction().commit();
}

Testing spring batch job stepScope

I'm trying to test a spring batch job that performs a read (get data from another application) process (simple calculation) and write (into the mongodb)
the reader is #StepScope
here is the postConstruct of the read task.
#PostConstruct
public void init(){
employees.addAll(getListOfEmployeesBy(affectationMotifService.findAllRegistrationNumbers()));
}
public List<EmployeeForSalaryDTO> getListOfEmployeesBy(List<String> registrationNumbers){
LOG.debug("request to get all the employees by registration numbers {}" , registrationNumbers);
return coreResourceFeign.getAllEmployeesForSalaryByRegistrationNumbers(registrationNumbers).getBody();
}
When I try to launch the test of the job or what ever test in the application. spring always runs the init() of the read task .. which will fail the test because I need to mock the coreResourceFeign.getAllEmployeesForSalaryByRegistrationNumbers(registrationNumbers) .
I can't mock the method because it runs before the test begin.
here is the test
#RunWith(SpringRunner.class)
#SpringBootTest(classes = {SalaryApp.class, SecurityBeanOverrideConfiguration.class})
public class SalaryJobServiceTest {
#Autowired
#InjectMocks
private SalaryJobService salaryJobService;
#Test
public void startJob() throws Exception {
SalaryJobDTO SalaryJobDTO = salaryJobService.start(Collections.emptyList());
Assert.assertNotNull(salaryJobDTO.getId());
}
}
I have no idea how to deal with spring batch tests. Any recommendation or help will be welcomed.
#PostConstruct will make sure your method is called immediately after the object is created. Spring application creates all the beans as per the configs while application start. This is expected behavior. If you do not want to call your method during application start up remove #PostConstruct and you can run your test mocking the dependent objects.
Rather you should use readers read method to load your data to the reader.

Integration Tests with PowerMock and Spring Boot

I'm doing some integration tests, on a Spring Boot application.
Usually the integration tests that I was used to develop, was regarding the application domain, without any external service involved.
Since this time I need to make an integration test on a service which uses both a database and an external service called by an SDK, I've tried doing something like the following:
#RunWith(PowerMockRunner::class)
#SpringBootTest
#PowerMockRunnerDelegate(SpringRunner::class)
#PrepareForTest(McpProductService::class)
class MyServiceIntegration {
#Mock
private ExternalService externalService;
#Autowired
#InjectMocks
private MyServiceImpl myService;
#Test
public void thisTestShouldWork() {
...
}
}
What is confusing me is: how should I declare myService attribute? Usually when I use Mockito + PowerMock in my Unit Tests, I usually test the implementation, not the whole Service Interface + Spring Injection. But I can't use #Autowired if I'm using just it's implementation, not the Interface.
Is there any best practice for this issue that I'm facing?
Disclaimer: I'm assuming that what you are after is an end-to-end test of a service interface, backed by multiple classes. I assume (and hope) that you don't have a single class handling both database and webservice integration.
I don't see the need to use PowerMock here, it is usually something one would use for testing legacy code with a lot of static stuff. If you are using Spring boot, your code should be of a quality that makes PowerMock unnecessary.
When writing an end-to-end test, the principles are the same as a per-class unit test, only with a larger scope:
With a unit test, you create an instance of the class under test, and mock all its external dependencies (other classes)
With an end-to-end test, you create an "instance" of your module under test, and mock its external dependencies.
So, here you should find a mechanism to mock the parts of your code that communicates with external sources, like web service clients, database classes (if you don't use an in-memory db for your test (you should)). This will typically be a Spring config that is almost identical to the one used in production, but with said parts mocked out. Then, you just #Inject the parts you need to communicate with in order to complete the test.
Assuming that you use component scan and annotations for all beans, you could mock the endpoint-classes and use profiles:
This code is based on memory only, might not work on copy-paste, but hopefully you could use the concepts..
#Profile("test")
#Configuration
public class TestConfiguration {
#Bean
#Primary
public SomeWebserviceClient someWebserviceClient() {
return mock(SomeWebserviceClient.class);
}
}
Production code:
#Service
public class SomeClass {
#Inject
private SomeWebserviceClient client;
}
Then in the test:
#RunWith(PowerMockRunner::class)
#SpringBootTest
#ActiveProfiles("test")
public class SomeTest {
#Inject
private SomeClass someClass;
#Inject
private SomeWebserviceClient client; //<< will inject mock
}
Mock will also be injected into SomeClass

integration testing spring service layer based on migrated data

#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations={"/applicationContext-test.xml"})
#Transactional
public class MyServiceTest {
#Resource(name="myService")
public MyService myService;
#Test
public void testSeomthing() {
//do some asserts using myService.whatever()
}
}
However the tests are based on data I migrate in, so every time I run my suite of tests I want to execute my unrelated migration code. I don't want to run a #Before in each test class. I want to run it once at beginning of complete test process, where can I put this ?
I would advice you to create a test bean somewhere with startup logic invoked in #PostConstruct:
#Service
public class TestBean {
#PostConstruct
public void init() {
//startup logic here
}
}
Obviously this bean should only be created for tests, the easiest way to achieve this is to place it in src/test/java in a package that is component-scanned by Spring for #Service-annotated classes.
Note: you must remember that #PostConstruct is not running in a transaction! See How to call method on spring proxy once initialised.
JUnit also offers a #BeforeClass annotation which you can place on a static method to initialize resources just once.

Unit testing controllers with annotations

I'm trying to write some unit tests for my controllers in a Spring MVC web app. I have already got a fairly comprehensive set of unit tests for the domain model, but for completeness I want to test the controllers too.
The issue I'm facing is trying to test them without loading a Spring context. I thought I could get around this with mocking, but the method in the controller has a #Transactional annotation which attempts to open a transaction (and fails with a NullPointerException because no Spring context is loaded).
Code example:
public class UsersController {
#Autowired private UserManager userManager;
#Transactional
#RequestMapping(method = RequestMethod.POST)
public ModelAndView create(User user) {
userManager.save(user);
ModalAndView mav = new ModelAndView();
mav.addObject("user", user);
mav.setViewName("users/view");
return mav;
}
}
So essentially I want to test the behaviour without loading a context and actually persisting the user.
Does anyone have any ideas on how I can achieve this?
Cheers,
Caps
I'd say mocking is the way to go here. The #Transactional annotation will have no effect unless there is a Spring context loaded and instructed to configure annotation-based transactions.
Make sure that you aren't instructing JUnit to run your test within a spring context by specifying something like:
#ContextConfiguration(locations = "classpath:spring/ITestAssembly.xml")
#RunWith(SpringJUnit4ClassRunner.class)
To prevent confusion, I keep my unit tests (not running in a spring context) in separate files than my integration tests. Typically all mocking occurs in the unit tests and not in integration tests.
The NullPointerException occurs not because of the Transactional, but because nothing gets injectedas UserManager. You have two options:
run with the spring test runner
mock the userManager and set it.

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