We Keep Coding

How to mock Mono.from(commandResult).block();

I have a class that invokes mongodb using reactive library and am writing a unit test that includes this private method. How to mock Mono.from(commandResult).block() using mockito?
private Document runCommand(final String command) {
final MongoDatabase db = mongoClient.getDatabase("admin");
final Bson bsonDocument = Document.parse(command).toBsonDocument();
final Publisher<Document> commandResult = db.runCommand(bsonDocument);
return Mono.from(commandResult).block();
}

Retuning Mono.just() worked
#Test
void initializeDBTest() {
final Document bsonDoc = Document.parse(isCSResponse);
Mockito.when(mongoClient.getDatabase("admin")).thenReturn(db);
Mockito.when(db.runCommand(Mockito.any())).thenReturn(Mono.just(bsonDoc));
manageDB.initializeDB();
}

Mock returned value of ResultSet inside the method to be tested that implements an interface

I'm trying to mock some data with Mockito for some tests, but I can't get it to work. My problem is that the value I want to mock is the return of a call inside the method I need to test.
I have a class, MyAccessor.java (that implements a service, MyService.java) that inside has a method, getMyMethod(String value), and inside that method there is a call to the DB:
final List<MyType> results = this.jdbcTemplate.query(sqlQuery, new RowMapper<MyType>() {
#Override
public MyType mapRow(final ResultSet rs, final int rowNum) throws SQLException {
final int fieldA = rs.getInt("column_name_1");
final int fieldB = rs.getInt("column_name_2");
final int fieldC = rs.getInt("column_name_3");
final int fieldD = rs.getInt("column_name_4");
return new MyType(fieldA , fieldB , fieldC , fieldD);
}
}, value);
There is a case where due to timeouts with the database, an empty list is returned by the rowMapper. So in that case it is not possible to do return results.get(0) because you will get an ArrayIndexOutOfBoundsException.
So I have a check:
if (!results.isEmpty()) {
return results.get(0);
} else {
return new MyType(0, 0, 0, 0);
}
Now, I want to test this particular scenario but I don't know how to mock the resultSet return so that the rowMapper returns an empty list. In my test class I have set:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = { ".....", "....."})
#TestPropertySource(".....")
public class MyClassTest {
#Mock
private JdbcTemplate jdbcTemplate;
#InjectMocks
#Autowired
private MyService myService;
#Before
public void initMocks() {
MockitoAnnotations.openMocks(this);
}
#Test
public void myTestMethod() {
Mockito.when(this.jdbcTemplate.query("SELECT NULL LIMIT 0", new RowMapper<Object>() {
#Override
public Object mapRow(ResultSet rs, int rowNum) throws SQLException {
return new ArrayList<>();
}
})).thenReturn(new ArrayList<Object>());
MyType result = this.myService.getMyMethod("value");
assertEquals(0, result.getFieldA());
assertEquals(0, result.getFieldB());
assertEquals(0, result.getFieldC());
assertEquals(0, result.getFieldD());
}
}
But the test fails because the result returned is from the database instead of an empty list to test the timeout case.
I think the problem may be because I'm injecting the mock in the service interface instead of the implementation, but I wanted to know if it can be done somehow so I don't have to test the mock for each implementation of that interface.
Or maybe I am using the Mockito framework wrong and in that case, how can I test correctly?
Regads.

I think you want something more like:
#Test
public void myTestMethod() {
Mockito.when(this.jdbcTemplate.query(eq("SELECT NULL LIMIT 0"), Mockito.any(RowMapper.class))
.thenReturn(new ArrayList<Object>());
}
Reason is because when mocking, you were saying only to return the empty list if both arguments to the query is exactly as you defined. In your case, you don't care about the exact instance of RowMapper.

I have found the problem. I was injecting the mock in the interface and not in the implementation of the interface. So I had to change:
#Mock
private JdbcTemplate jdbcTemplate;
#InjectMocks
#Autowired
private MyService myService;
to:
#Mock
private JdbcTemplate jdbcTemplate;
#InjectMocks
#Autowired
private MyAccessor myAccessor;
#Autowired
private MyService myService;
And inside the test this:
MyType result = this.myService.getMyMethod("value");
to:
MyType result = this.myAccessor.getMyMethod("value");
I don't know if there is a better way to do this, without having to instantiate all the implementations that the service may have.
Regards.

New to Java. Need help to understand testing for my function with some dependencies

#Autowired
private Publisher Publisher;
private int Id = 12345;
private BClient bClient = new BClient(Id);
private Map<Integer, Boolean> defaultBooleanValueMap;
private LoadCache<Integer, Boolean> booleanCache = CacheBuilder.newBuilder()
.refreshAfterWrite(refreshRate, TimeUnit.SECONDS)
.build(
new CacheLoader<Integer, Boolean>() {
#Override
public Boolean load(Integer id) throws Exception {
return fetchBooleanValue(id);
}
}
);
private boolean fetchBooleanValue(int id) {
long fetchStart = System.currentTimeMillis();
boolean val = bClient.getBoolean(id, defaultBooleanValueMap.get(id));
publisher.publish(
publisher.getDistributionMetric("fetchtime.bool", System.currentTimeMillis() - fetchStart));
return val;
}
public boolean getBoolean(int id) {
return booleanCache.getUnchecked(id);
}
//Trying to test getBoolean(int id) function. I'm mocking bClient, Publisher. Not sure how to properly test it
// Could anyone help me understand how to test it
//testing with
SomeClass someClass = new SomeClass();
#Mock
Publisher publisher;
#Mock
BClient bClient;
#Test
public void testGetBoolean(){
bClient = new BClient(12345);
Map<Integer,Boolean> defaultBooleanValueMap = null;
defaultBooleanValueMap.put(123, false);
when(bClient.getBoolean(123,
defaultBooleanBregValueMap.get(123))).thenReturn(false);
boolean b = someClass.getBoolean(123);
assertFalse(b);
}
// i'm don't know if i'm doing it right

Are you using Mockito?
It's good practice to not start a field name with a capital (Publisher for instance)
Personally i think it will be better to make all these methods protected instead of private, so that you can test each of them separately.
however this would be an example of a unit test for your code.
You can use Mockito to check if certain method calls are fired the amount of time you expect them to be fired.
I did not include all but you can just add if you need more tests.
Further i recommend to read about Mockito as it has some really powerful unit test tools
#Test
public void testGetBoolean () {
xxx.getBoolean
//the following line can only be done if you spy your service
Mockito.verify(xxx, times(1)).fetchBooleanValue(any());
//this line can be done if you mock bClient
Mockito.verify(bClient , times(1)).getBoolean(any(), any()); //Mockito.any() or you can fill in the real values if you really want.
//this line can be done if you mock Publisher
Mockito.verify(publisher, times(1)).publish(any); //again any or the real value you want to pass
}
I just now saw your unit tests, you can inject the mocks in you class with the following anotatation:
#InjectMocks
SomeClass someClass;
when mocking a class you don't manually have to create it again.
You don't have to mock the Bclient as you already create it with "new Bclient" instead of autowiring it.
I feel the #InjectMocks is not working because you didn't tell Spring that your class is a service component.
#Service
public class SomeClass {
//insert code here
}

Problems with null pointer using mockito

I'm trying to test a method. And in this method, a new Object is instancied, but I don't want it, otherwise other class will be tested.
How I tell to mockito dont intanciate it?
#Component
#EnableScheduling
public class VerificadorDeNovasAssinaturas {
private DocuSign docuSign;
private ApiClient apiClient;
#Autowired
private DocuSignProperties docuSignProperties;
public EnvelopesInformation verificaNovasAssinaturas() throws Exception {
this.docuSign = new DocuSign(docuSignProperties); // I don't want mockito instanciate DocuSign
this.apiClient = docuSign.getApiClient();
this.apiClient.addDefaultHeader("Authorization", "Bearer " + docuSign.getoAuthToken().getAccessToken());
And my test class:
#SpringBootTest
#RunWith(SpringRunner.class)
#ActiveProfiles("test")
public class VerificadorDeNovasAssinaturasTest {
#InjectMocks
private VerificadorDeNovasAssinaturas verificador;
private DocuSignProperties docuSignProperties;
private ApiClient apiClient;
private UserInfo userInfo;
private OAuthToken oAuthToken;
#Mock
private DocuSign docuSign;
#Before
public void initialize() throws Exception {
docuSignProperties = new DocuSignProperties();
docuSignProperties.setBaseUrl("https://demo.docusign.net/restapi");
docuSignProperties.setBasePath("/restapi");
setApiClientConfigurations();
when(docuSign.getApiClient()).thenReturn(this.apiClient);
when(docuSign.getoAuthToken()).thenReturn(this.oAuthToken);
...}
private void setApiClientConfigurations() throws Exception {
this.apiClient = new ApiClient(this.docuSignProperties.getBaseUrl());
this.oAuthToken = getOAuth();
... }
#Test
public void testaVerificacaoDeNovasAssinaturas() throws Exception {
EnvelopesInformation results = verificador.verificaNovasAssinaturas();
assertNotNull(results);
}
I don't want mockito instanciate a new DocuSign, because this is not the reason of the test. There is some way do ignore this step?

Well, Mockito can not change something if your code( Code to be tested, Which you intend to) does something, However you can mock it so that it does not create a new object (rather have your "Mocked Object"), so that you can verify something against the expected behavior.
In your code if you change few lines , you can achieve what you want, like -
Create a DocuSignService class and there you create this new object in say some - getDocuSign method. Then your code looks something like below -
#Autowired
private DocuSignService docuSignService ;
this.docuSign = new DocuSign(docuSignProperties); // This is what you have
this.docuSign = this.docuSignService.getDocuSign() ; // This is new code
Now in your test case -
#Mock
DocuSignService docuSignService ;
#Mock
private DocuSign docuSign;
//.
//.
Mockito.when(this.docuSignService.getDocuSign()).thenReturn(docuSign);
Now you have control on this object.

I resolved it using powerMockito.
DocuSign docuSign = PowerMockito.mock(DocuSign.class);
PowerMockito.whenNew(DocuSign.class).withAnyArguments().thenReturn(docuSign);

Test the service in springboot

This is the service I have :
#Service
public class UserInfoService {
#Autowired
private UserInfoServiceClient UserInfoServiceClient; // Call another Rest API
public ResponseEntity<ResponseUserInfoData> sendUserInfo(String UserId) throws RuntimeException {
ResponseUserInfoData responseUserInfoData = new ResponseUserInfoData();
//Get the body from the User service client
UserServiceDTO UserServiceDTO = UserInfoServiceClient.sendResponse(UserId).getBody();
//Set the values of responseUserInfoData
Optional<UserServiceDTO> UserServiceDTOOptional = Optional.ofNullable(UserServiceDTO);
if (UserServiceDTOOptional.isPresent()) {
UserServiceDTOOptional.map(UserServiceDTO::getId).ifPresent(responseUserInfoData::setid);
}
else return ResponseEntity.noContent().build();
}
}
I have to test it. I'm new to JUnit testing. I want to test the following points:
To check if the service return the response entity
To check if the get and set method works
This is what I started?
#RunWith(MockitoJUnitRunner.class)
public class ServiceTests {
#InjectMocks
private UserInfoService UserInfoService;
#Mock
private UserInfoServiceClient UserInfoServiceClient;
#Mock
private UserServiceDTO UserServiceDTO;
#Test
public void shouldReturnUserInfoData() throws IOException{
UserInfoService.sendUserInfo("ABC");
}
}
Any help is appreciated?

Mockito is useful to mock the dependencies of the service so that you can test all the code path in you service. In your case you will want to stub the call to serInfoServiceClient.sendResponse(UserId) and have it return a specific UserServiceDTO for each test case.
The test file looks like it is set up correctly, you only need to mock the method to give you the result you need for the particular test, for example
#RunWith(MockitoJUnitRunner.class)
public class ServiceTests {
#InjectMocks
private UserInfoService UserInfoService;
#Mock
private UserInfoServiceClient UserInfoServiceClient;
#Test
public void shouldReturnUserInfoData() throws IOException{
final String userId = "123";
// The mocked return value should be set up per test scenario
final UserServiceDto dto = new UserServiceDto();
final ResponseEntity<UserServiceDTO> mockedResp = new ResponseEntity<>(dto, HttpStatus.OK);
// set up the mock service to return your response
when(UserInfoServiceClient.sendResponse(userId)).thenReturn(mockedResp);
// Call your service
ResponseEntity<ResponseUserInfoData> resp = UserInfoService.sendUserInfo(userId);
// Test the result
Assert.isNotNull(resp);
}
}
There are also other ways to mock the dependencies using Mockito. I suggest going through the quick start of https://site.mockito.org/