null service when testing with MockitoJUnitRunner - java

I have this test in my Spring Boot app., but when I run the test, boniUserService is null
#RunWith(MockitoJUnitRunner.class)
public class BoniUserServiceTest {
private BoniUserService boniUserService;
#Test
public void getUserById() {
boniUserService.getUserById("ss");
}
}

The runner of your test that you specify with #RunWith annotation specify who is going to process the annotation in your test class. They process the annotation in your test class and mock objects for you. In your case you have annotated your class with #RunWith(MockitoJUnitRunner.class) So there should be some annotation of Mockito in your class to be processed by MockitoJUnitRunner. To achieve your goal you can annotate your bean by #MockBean annotation.
#RunWith(MockitoJUnitRunner.class)
public class BoniUserServiceTest {
#MockBean
private BoniUserService boniUserService;
#Test
public void getUserById() {
boniUserService.getUserById("ss");
}
}
Note that in this approach the Context of the Spring Application is not loaded. Usually you want to test one of your component based on mocked behavior of other components. So usually you achieve that like this:
#RunWith(SpringRunner.class)
#SpringBootTest
public class BoniUserServiceTest {
#Autowired
private BoniUserService boniUserService;
#MockBean
private BoniUserRepository boniUserRepository;
#Test
public void getUserById() {
given(this.boniUserRepository.getUserFromRepository()).willReturn(new BoinoUsr("test"));
boniUserService.getUserById("ss");
}
}

You need to have the application context up to make it work, it can be achieved by using the #SpringBootTest annotation, and then you need to inject your service using the #Autowired annotation. Something like this:
#SpringBootTest
#RunWith(MockitoJUnitRunner.class)
public class BoniUserServiceTest {
#Autowired
private BoniUserService boniUserService;
#Test
public void getUserById() {
boniUserService.getUserById("ss");
}
}

Related

Initialize Mocks in test before #BeforeStep

I have a custom reader with an #BeforeStep function in order to initialize some data. These data are comming from an external database.
#Component
public class CustomReader implements ItemReader<SomeDTO> {
private RestApiService restApiService;
private SomeDTO someDTO;
#BeforeStep
private void initialize() {
someDTO = restApiService.getData();
}
#Override
public SomeDTO read() {
...
return someDTO
}
}
In my unit test i need to mock the calls to the external database.
#RunWith(SpringRunner.class)
#SpringBootTest(classes = NedBatchApplication.class)
public class CustomReaderTest {
#Autowired
CustomReader customReader;
#Mock
RestApiService restApiService;
#Before
private void setup() {
MockitoAnnotations.initMocks(this);
ReflectionTestUtils.setField(customReader, "restApiService", restApiService);
Mockito.when(restApiService.getData().thenReturn(expectedData);
}
}
The problem i am facing is the #BeforeStep is executed before the #Before from the unit test, when i lauch my Test. So restApiService.getData() returns null instead of expectedData.
Is there a way to achieve what i want or do i need to do it with a different approach ?
After some reflexion with a co-worker he gave me a solution :
#RunWith(SpringRunner.class)
#SpringBootTest(classes = NedBatchApplication.class)
public class CustomReaderTest {
CustomReader customReader;
#Mock
RestApiService restApiService;
#Before
private void setup() {
MockitoAnnotations.initMocks(this);
Mockito.when(restApiService.getData().thenReturn(expectedData);
this.customReader = new CustomReader(restApiService);
}
#Test
public void test() {
customReader.initialize();
(...)
}
}
Are you certain that the BeforeStep is running before the Before annotation (by using logging or similar?).
It's possible your Mockito invocation is not fully correct. Try using Mockito.doReturn(expectedData).when(restApiService).getData() instead.
As an alternative approach, if the RestApiService was autowired in your custom reader, you'd be able to use the #InjectMocks annotation on the custom reader declaration in your test, which would cause the mocked version of your restApiService to be injected to the class during the test.
Usually when using Spring based tests, try to make dependencies like restApiService (the ones you would like to mock) to be spring beans, and then you can instruct spring to create mock and inject into application context during the application context creation with the help of #MockBean annotation:
import org.springframework.boot.test.mock.mockito.MockBean;
#RunWith(SpringRunner.class)
#SpringBootTest(classes = NedBatchApplication.class)
public class CustomReaderTest {
#MockBean
private RestApiService restApiService;
}

Unit testing with SpringJUnit4ClassRunner using only #Component and #Autowired

I have the following class:
#Component
public class MyClass {
#Autowired MyPojo pojo;
}
How do i test it without mocking the injected beans? I do not have a configuration [XML or declarative].
I have done the following:
#RunWith(SpringJUnit4ClassRunner.class)
#ComponentScan
public class MyClassTest {
#Autowired MyClass myClass;
#Test
public void test() {
this.myClass...()
}
}
If you do not want use any type of configuration, neither Java nor XML config, you can use #ContextConfiguration with your component classes listed:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = { MyPojo.class, MyClass.class })
public class MyClassTest {
#Autowired
private MyClass myClass;
#Test
public void test() {
// myClass...
}
}
Please note that MyPojo class should also be annotated with #Component.
However, in the real life scenario you probably will need at least one #Configuration class (which can be also used with #ContextConfiguration).
Please refer Spring Documentation for more information about Spring integration tests support.

Mockito with jUnit ParallelComputer

I am writing integration test for a spring boot controller for concurrent access of APIs. I want to run these tests in parallel using a common setup. I looked at jUnit ParallelComputer but couldn't find a way to create a common setup. Even if I find a way to do the common setup the #Autowired variables are not getting instantiated, they remain null. Am I missing something?
Here is an example of what I am doing:
#RunWith(SpringJUnit4ClassRunner.class)
public class ParallelComputerTest {
#Test
public void test() {
Class[] cls={ParallelTest1.class};
//Parallel all methods in all classes
JUnitCore.runClasses(new ParallelComputer(true, true), cls);
}
}
#RunWith(SpringJUnit4ClassRunner.class)
#SpringBootTest(webEnvironment =
SpringBootTest.WebEnvironment.RANDOM_PORT)
#AutoConfigureMockMvc
public class ParallelTest1 {
#Autowired
private MockMvc mockMvc;
#Autowired
private someClass;
#Test public void a(){
//someClass and mockMvc is null here
//do something
}
#Test public void b(){}
}
Why is mockMvc and the other classes I #Autowired null?
I need a way to spin up the server, do some common setup and run the tests in parallel.

Configure #MockBean component before application start

I have a Spring Boot 1.4.2 application. Some code which is used during startup looks like this:
#Component
class SystemTypeDetector{
public enum SystemType{ TYPE_A, TYPE_B, TYPE_C }
public SystemType getSystemType(){ return ... }
}
#Component
public class SomeOtherComponent{
#Autowired
private SystemTypeDetector systemTypeDetector;
#PostConstruct
public void startup(){
switch(systemTypeDetector.getSystemType()){ // <-- NPE here in test
case TYPE_A: ...
case TYPE_B: ...
case TYPE_C: ...
}
}
}
There is a component which determines the system type. This component is used during startup from other components. In production everything works fine.
Now I want to add some integration tests using Spring 1.4's #MockBean.
The test looks like this:
#RunWith(SpringRunner.class)
#SpringBootTest(classes = MyWebApplication.class, webEnvironment = RANDOM_PORT)
public class IntegrationTestNrOne {
#MockBean
private SystemTypeDetector systemTypeDetectorMock;
#Before
public void initMock(){
Mockito.when(systemTypeDetectorMock.getSystemType()).thenReturn(TYPE_C);
}
#Test
public void testNrOne(){
// ...
}
}
Basically the mocking works fine. My systemTypeDetectorMock is used and if I call getSystemType -> TYPE_C is returned.
The problem is that the application doesn't start. Currently springs working order seems to be:
create all Mocks (without configuration all methods return null)
start application
call #Before-methods (where the mocks would be configured)
start test
My problem is that the application starts with an uninitialized mock. So the call to getSystemType() returns null.
My question is: How can I configure the mocks before application startup?
Edit: If somebody has the same problem, one workaround is to use #MockBean(answer = CALLS_REAL_METHODS). This calls the real component and in my case the system starts up. After startup I can change the mock behavior.
In this case you need to configure mocks in a way we used to do it before #MockBean was introduced - by specifying manually a #Primary bean that will replace the original one in the context.
#SpringBootTest
class DemoApplicationTests {
#TestConfiguration
public static class TestConfig {
#Bean
#Primary
public SystemTypeDetector mockSystemTypeDetector() {
SystemTypeDetector std = mock(SystemTypeDetector.class);
when(std.getSystemType()).thenReturn(TYPE_C);
return std;
}
}
#Autowired
private SystemTypeDetector systemTypeDetector;
#Test
void contextLoads() {
assertThat(systemTypeDetector.getSystemType()).isEqualTo(TYPE_C);
}
}
Since #TestConfiguration class is a static inner class it will be picked automatically only by this test. Complete mock behaviour that you would put into #Before has to be moved to method that initialises a bean.
I was able to fix it like this
#RunWith(SpringRunner.class)
#SpringBootTest(classes = MyWebApplication.class, webEnvironment = RANDOM_PORT)
public class IntegrationTestNrOne {
// this inner class must be static!
#TestConfiguration
public static class EarlyConfiguration {
#MockBean
private SystemTypeDetector systemTypeDetectorMock;
#PostConstruct
public void initMock(){
Mockito.when(systemTypeDetectorMock.getSystemType()).thenReturn(TYPE_C);
}
}
// here we can inject the bean created by EarlyConfiguration
#Autowired
private SystemTypeDetector systemTypeDetectorMock;
#Autowired
private SomeOtherComponent someOtherComponent;
#Test
public void testNrOne(){
someOtherComponent.doStuff();
}
}
You can use the following trick:
#Configuration
public class Config {
#Bean
public BeanA beanA() {
return new BeanA();
}
#Bean
public BeanB beanB() {
return new BeanB(beanA());
}
}
#RunWith(SpringRunner.class)
#ContextConfiguration(classes = {TestConfig.class, Config.class})
public class ConfigTest {
#Configuration
static class TestConfig {
#MockBean
BeanA beanA;
#PostConstruct
void setUp() {
when(beanA.someMethod()).thenReturn(...);
}
}
}
At least it's working for spring-boot-2.1.9.RELEASE
Spring's initialization is triggered before #Before Mockito's annotation so the mock is not initialized at the time the #PostConstruct annotated method is executed.
Try to 'delay' your system detection using #Lazy annotation on the SystemTypeDetector component. Use your SystemTypeDetector where you need it, keep in mind that you cannot trigger this detection in a #PostConstruct or equivalent hook.
I think that it's due to the way you autowire your dependencies. Take a look at this (specially the part about 'Fix #1: Solve your design and make your dependencies visible'). That way you can also avoid using the #PostConstruct and just use the constructor instead.
What U are using, is good for a unit tests:
org.mockito.Mockito#when()
Try to use the following methods for mocking spring beans when the context is spined-up:
org.mockito.BDDMockito#given()
If u are using #SpyBean, then u should use another syntax:
willReturn(Arrays.asList(val1, val2))
.given(service).getEntities(any());

Spring's #Retryable not working when running JUnit Test

I have this test:
#RunWith(MockitoJUnitRunner.class)
public class myServiceTest {
#InjectMocks
myService subject;
private myService spy;
#Before
public void before() {
spy = spy(subject);
}
#Test
public void testing() {
when(spy.print2()).thenThrow(new RuntimeException()).thenThrow(new RuntimeException()).thenReturn("completed");
spy.print1();
verify(spy, times(3)).print2();
}
and then I have:
#Service("myService")
public class myService extends myAbstractServiceClass {
public String print1() {
String temp = "";
temp = print2();
return temp;
}
#Retryable
public String print2() {
return "completed";
}
}
then I have this interface(which my abstractService implements):
public interface myServiceInterface {
#Retryable(maxAttempts = 3)
String print1() throws RuntimeException;
#Retryable(maxAttempts = 3)
String print2() throws RuntimeException;
}
but, I get a runtimeexception thrown when I run the test, leading me to believe it is not retrying. Am I doing this wrong?
This is because you are not using the SpringJUnitClassRunner.
Mockito and your own classes are not taking the #Retryable annotation in account. So you rely on the implementation of Spring to do so. But your test does not activate Spring.
This is from the SpringJUnit4ClassRunner JavaDoc:
SpringJUnit4ClassRunner is a custom extension of JUnit's BlockJUnit4ClassRunner which provides functionality of the Spring TestContext Framework to standard JUnit tests by means of the TestContextManager and associated support classes and annotations.
To use this class, simply annotate a JUnit 4 based test class with #RunWith(SpringJUnit4ClassRunner.class) or #RunWith(SpringRunner.class).
You should restructure your test class at least to something like:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes=MyConfig.class)
public class MyServiceTest {
#Configuration
#EnableRetry
#Import(myService.class)
public static class MyConfig {}
...
What am I doing there?
activate the Spring JUnit hook
specify the Spring context configuration class
define the spring configuration and import your service as a bean
enable the retryable annotation
Are there some other pitfalls?
Yes, you are using Mockito to simulate an exception. If you want to test this behaviour with Spring like this, you should have a look at Springockito Annotations.
But be aware of that: Springockito you will replace the spring bean completely which forces you to proxy the call of your retryable. You need a structure like: test -> retryableService -> exceptionThrowingBean. Then you can use Springockito or what ever you like e.g. ReflectionTestUtils to configure the exceptionThrowingBean with the behaviour you like.
You should reference the interface type of your service in your test: MyServiceInterface
And last but not least. There is a naming convention nearly all Java developers follow: class names have first letter of each internal word capitalized
Hope that helps.
Another way:
#EnableRetry
#RunWith(SpringRunner.class)
#SpringBootTest(classes={ServiceToTest.class})
public class RetryableTest {
#Autowired
private ServiceToTest serviceToTest;
#MockBean
private ComponentInsideTestClass componentInsideTestClass;
#Test
public void retryableTest(){
serviceToTest.method();
}
}
I think you should let Spring manage the bean, create the appropriate proxy and handle the process.
If you want to mock specific beans, you can create mocks and inject them to the service under test.
1st option could be unwrapping proxied service, creating mocks and manually injecting them:
#RunWith(SpringRunner.class)
#ContextConfiguration(classes = {RetryConfiguration.class})
#DirtiesContext
public class TheServiceImplTest {
#Autowired
private TheService theService;
#Before
public void setUp(){
TheService serviceWithoutProxy = AopTestUtils.getUltimateTargetObject(theService);
RetryProperties mockRetryProperties = Mockito.mock(RetryProperties.class);
ReflectionTestUtils.setField(serviceWithoutProxy, "retryProperties", mockRetryProperties);
}
#Test
public void shouldFetch() {
Assert.assertNotNull(theService);
}
}
In this example, I mocked one bean, RetryProperties, and injected into the service. Also note that, in this approach you are modifying the test application context which is cached by Spring. This means that if you don't use #DirtiesContext, service will continue its way with mocked bean in other tests. You can read more here
Second option would be creating a test specific #Configuration and mock the depended bean there. Spring will pick up this new mocked bean instead of the original one:
#RunWith(SpringRunner.class)
#ContextConfiguration(classes = {RetryConfiguration.class, TheServiceImplSecondTest.TestConfiguration.class})
public class TheServiceImplSecondTest {
#Autowired
private TheService theService;
#Test
public void shouldFetch() {
Assert.assertNotNull(theService);
}
#Configuration
static class TestConfiguration {
#Bean
public RetryProperties retryProperties() {
return Mockito.mock(RetryProperties.class);
}
}
}
In this example, we have defined a test specific configuration and added it to the #ContextConfiguration.

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