I have seen a few examples of people switching from Mockito to JMockit, but I am doing the opposite. I am not really sure what to do with the #Mocked parameters. Do these just become #Mock instance variables? I think the NonStrictExpectations clause should become "when" clauses like:
when(rpManager.login()).thenReturn(true);
and the Verifications section becomes "verify" clauses.
This is an example of a full test case I am converting.
#Test
public void testGetOffersUnsuccessfulResponse(#Mocked final RPRequest mockRequest, #Mocked final RPResponse mockResponse) {
final String sessionId = "123";
new NonStrictExpectations() {{
rpManager.login(); returns(true);
rpManager.newRequest(anyString); returns(mockRequest);
mockRequest.sendRequest(); returns(mockResponse);
mockResponse.isSuccess(); returns(false);
}};
final EpiphanyConnection connection = new EpiphanyConnection(getDummyConnectionProperties(), getDummyActionMapping());
assertTrue(connection.connect());
final InteractionContext interactionContext = new InteractionContext();
interactionContext.setRequestContext(new RequestContext());
interactionContext.getRequestContext().setAction(getDummyActionMapping().keySet().iterator().next());
interactionContext.setUserContext(new UserContext());
interactionContext.getUserContext().setSessionId(sessionId);
final OfferTranslator offerTranslator = connection.fetchCommunications(interactionContext);
assertNotNull(offerTranslator);
new Verifications() {{
// failure in the below likely indicates mismatched JSON string.
mockRequest.setData("SessionId", sessionId);
mockRequest.sendRequest(); times=1;
}};
}
Mockito, you are correct there, does not expect any when clause to be actually needed. Like the name implies, WHEN this and that happens, then do something - if it did not happen, then that's ok as well.
To make sure that something has actually been called, use verify.
#Mock will create a mocked instance, correct:
#Mock
private MyService service; // will result in a mocked "MyService" instance
Don't forget to either call MockitoAnnotations.initMock(this); or to use #RunWith(MockitoJUnitRunner.class) to make sure the annotations are actually used.
Related
I'm having a hard time figuring out how to mock a KafkaConsumer. Below is the basic structure of my code.
public void run() {
...
try (KafkaConsumer<String, String> consumer = new KafkaConsumer<>(kafkaParams)) {
consumer.subscribe(topic);
ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(pollInterval));
methodToProcessRecords();
...
}
}
I want to do something like this:
whenCreateNewConsumer().thenReturn(mockConsumer);
when(mockConsumer.poll()).thenReturn(mockConsumerRecords);
I'm having a hard time figuring out how to mock a KafkaConsumer
Use MockConsumer
Alternatively, it's not really clear what you are consuming from. If you want to produce and consume, use Kafka Streams TopologyTestDriver
First change your class (to be tested) variable type to use Consumer Interface instead of Class. instead of using KafkaConsumer. use this Consumer interface
there should not be any code change needed, just variable type change.
(same applies to producer also)
Now in your unit test class
private MockConsumer<String, String> mockConsumer = new MockConsumer<>(OffsetResetStrategy.EARLIEST);
now you can assign the above variable to your class which you are trying to unit test
If your consumer is public, its very easy to set. If its private variable, you can use reflection
ToBeTested class = new ToBeTested();
Field field = class.getClass().getDeclaredField("privateVariableNameOfKafkaConsumer");
field.setAccessible(true);
field.set("class", mockConsumer);
The context
I have a simple method that I'm testing using the mockito library.
The problem
I have a error:
"[MockitoHint] ReceiveServiceTest.testGetFileDto (see javadoc for MockitoHint):
[MockitoHint] 1. Unused... -> at .ReceiveServiceTest.testGetFileDto(ReceiveServiceTest.java:46)
[MockitoHint] ...args ok? -> at ReceiveService.getFileDto(ReceiveService.java:28)
I dont understand way.
The code
#RunWith(MockitoJUnitRunner.class)
public class ReceiveServiceTest {
private List<File> filePaths = new ArrayList<>();
#InjectMocks
private ReceiveService receiveService;
#Mock
private FindFiles findfiles;
#Mock
private ReadByte readByte;
#Before
public void before() {
filePaths.add(new File("d://folder//test1_message_received"));
filePaths.add(new File("d://folder//test2_message_received"));
filePaths.add(new File("d://folder//test3_message_received"));
}
#Test
public void testGetFileDto() throws IOException {
// Given
byte[] resultByteArr = new byte[1028];
when(findfiles.getPathFiles()).thenReturn(filePaths);
when(readByte.readByteArrFromFile(new File("d://folder//test3_message_received"))).thenReturn(resultByteArr);
List<MessageDTO> result = receiveService.getFileDto();
//some assert
}
method
#Autowired
private FindFiles findFiles;
#Autowired
private ReadByte readByte;
public List<MessageDTO> getFileDto() throws IOException {
List<MessageDTO> fileDtos = new ArrayList<>();
for (File file : findFiles.getPathFiles()) {
fileDtos.add(new MessageDTO(Base64.getEncoder().encode(readByte.readByteArrFromFile(new File(file.getPath()))),
file.getName(), "zip", null));
}
return fileDtos;
}
I think mocks are not being initialized. Please initialize the mocks in the #Before method.
#Before
public void init() {
initMocks(this);
}
This should solve the problem I guess.
Here is solution for my problem. I added foreach loop. Now the mock works, but byte [] is different than what it should return.
// Given
byte[] mockByteArr = new byte [2048];
when(findfiles.getPathFiles()).thenReturn(filePaths);
for (File filePath : filePaths) {
when(readByte.readByteArrFromFile(new File(filePath.getPath()))).thenReturn(mockByteArr);
}
//When
List<MessageDTO> result = receiveService.getFileDto();
//Then
assertEquals(3, result.size());
assertEquals(mockByteArr, result.get(1).getContent());
Your problem is, that you create a new object in the following line:
when(readByte.readByteArrFromFile(new File("d://folder//test3_message_received"))).thenReturn(resultByteArr);
Mockito needs to know which real object is passed to the method so that it can return the appropriate thenReturn-value. So if you pass the actual reference into it, your code will work, but also only if you specify all the values which are listed. Otherwise you may get a NullPointerException.
By the way, calling new File(file.getPath()) seems redundant to me. You can just use file instead.
So with the following your code might work better:
when(readByte.readByteArrFromFile(filePaths.get(0)).thenReturn(resultByteArray);
but then you need to specify it for all entries.
Alternatively, use a Matcher instead:
when(readByte.readByteArrFromFile(ArgumentMatchers.any(File.class))).thenReturn(resultByteArr);
or specify the actual argument matching you require as matchers can be very powerful in that regard.
Previously the answer contained the following, which is still true, but not as concise as the answer above:
It's been a long time since I last used mocks (and I am even proud of it ;-)).
The message already states that one should consult the javadoc and there I found the following:
Those are hints - they not necessarily indicate real problems 100% of the time.
Nonetheless, I believe the problem is with the following statement:
when(readByte.readByteArrFromFile(new File("d://folder//test3_message_received"))).thenReturn(resultByteArr);
I think you need to specify a return for every entry in the filePaths or make the call more generic using Matchers.any() (or any other appropriate Matcher).
I Have a class for which i want to write a Junit unit test case.
public class ComparatorUtil {
public static Map<String, ValueDifference<Object>> compareJsonObject(Object srcObject, Object targetObject)
throws JsonGenerationException, JsonMappingException, IOException {
String initialJson = ConverterUtil.convertObjectToJson(srcObject);
String updatedJson = ConverterUtil.convertObjectToJson(targetObject);
Gson g = new Gson();
Type mapType = new TypeToken<Map<String, Object>>(){}.getType();
Map<String, Object> firstMap = g.fromJson(initialJson, mapType);
Map<String, Object> secondMap = g.fromJson(updatedJson, mapType);
Map<String, MapDifference.ValueDifference<Object>> diffMap = Maps.difference(firstMap, secondMap).entriesDiffering();
return diffMap;
}
}
public class ConverterUtil {
public static String convertObjectToJson(Object o)
throws JsonGenerationException, JsonMappingException, IOException {
ObjectMapper mapperObj = new ObjectMapper();
return mapperObj.writeValueAsString(o);
}
}
Junit test case written by me:-
#RunWith(PowerMockRunner.class)
#PrepareForTest(ConverterUtil.class)
public class ComparatorUtilTest {
#Before
public void setUp() {
PowerMockito.mockStatic(ConverterUtil.class);
}
#Test
public void testValueDiff() throws JsonGenerationException, JsonMappingException, IOException {
TestObject srcObject = new TestObject();
srcObject.setColor("white");
srcObject.setId(1);
TestObject targetObj = new TestObject();
targetObj.setColor("white");
targetObj.setId(1);
targetObj.setSuffix("AA");
ComparatorUtil.compareJsonObject(srcObject, targetObj);
PowerMockito.verifyStatic(VerificationModeFactory.times(2));
ConverterUtil.convertObjectToJson(srcObject);
ConverterUtil.convertObjectToJson(targetObj);
}
}
When I am running the test class, I am getting a Null Pointer Exception as the initialJson and updatedJson is coming to be null. Can anyone please tell me where am I doing wrong?
So many things so wrong here.
You seem to assume how to use PowerMock. But what you put together simply doesn't make sense! You need to create a mocking specification using 'when().thenReturn()' for example.
Meaning: it is not enough to instruct PowerMock that a certain class will be mocked. You have to tell PowerMock about the actual values to be returned when these static methods are invoked.
so start by reading a good tutorial top to bottom. Don't use PowerMock for your own code, instead look how a tutorial solves a simple problem.
Then: PowerMock comes at certain cost. So you avoid using it. You rather should step back and look into reworking your code so that it can be tested without the need to mock static methods. You see, we are talking about code that transforms some input into some output. You should be able to write production and test code that requires no mocking at all for such situations. If at all, you should use frameworks such as Mockito - good production code can be tested without PowerMock.
More specifically: why is there a need to mock the static method? That seems to indicate that your ObjectMapper doesn't work in your unit test setup. It starts right there!
You see, a good unit test for your conversion method should simply look like:
assertThat(someConverterUnderTest.convert(fineTunedInput), is(expectedOutput));
That's it! You should design your converter to fully work in your unit test environment. And then all need for mocks is gone. In other words: you are currently testing implementation details. Instead you should always try testing the public contract of your methods. Testing implementation details is sometimes unavoidable, but as written before: the code you are showing here should really really be tested without mocks.
Then: even when you need mocks: the static methods are getting in your way. That is a clear signal that you shouldn't be using static here! Instead, you turn those elements that might require mocking either into parameters or into fields of your classes under test. Because then you can simply inject mocked objects. Which means that you don't need the PowerMock(ito) tooling anymore.
I have been tasked to figure out why this JUnit Test is failing. What I have found is that instead of returning an ArrayList (like the getDeligationsForLoggedInUser is SUPPOSED to return, it returns a LinkedList for "userList".
#SuppressWarnings("unchecked")
#Test
public void test_getDelegationsForLoggedInUser()
{
String userId="Abcd";
List<String> expectedUserList= new ArrayList<String>();
expectedUserList.add("efghi");
expectedUserList.add("jklmn");
expectedUserList.add("opqrs");
when(namedParameterJdbcTemplate.queryForObject(anyString(),anyMap(), any(RowMapper.class))).thenReturn(expectedUserList);
List<String> userList= workflowProcessDAOImpl.getDelegationsForLoggedInUser(userId);
verify(namedParameterJdbcTemplate, times(1)).query(sqlCaptor.capture(), namedParameterMap.capture(), rowMapperCaptor.capture());
assertThat(userList, is(expectedUserList));
assertThat(sqlCaptor.getValue(), is(SQLConstantsSysConfigV1.getInstance().GET_USERIDS_FOR_DELEGATES));
}
Does anyone have any idea why this is the case?
You mock in this test the method queryForObject, but test on the method query.
I suppose that your code defines a mock of the function somwhere else, isn't it? It could then simply be the result of a copy/paste operation...
I also had the same problem. To solve that I replaced Mockito.anyList() (if param required is list) and Mockito.anyLong() (if param required is long). Example:-
Mockito.when(testService.getData(Mockito.anyLong(),
Mockito.anyList(), Mockito.anyList())).thenReturn(SOME_RESPONSE_DATA);
I am trying to use PowerMockito to mock the creation of the java.net.URL class in my code that I'm testing. Basically, I want to prevent the real HTTP request from occurring and instead 1) check the data when the request is made and 2) supply my own test data back on a mocked response. This is what I'm trying:
#RunWith(PowerMockRunner.class)
#PrepareForTest({ URL.class, MockedHttpConnection.class })
public class Test {
URL mockedURL = PowerMockito.mock(URL.class);
MockedHttpConnection mockedConnection = PowerMockito.mock(MockedHttpConnection.class);
...
PowerMockito.whenNew(URL.class).withParameterTypes(String.class).withArguments("MyURLString").thenReturn(mockedURL);
PowerMockito.when(mockedURL.openConnection()).thenReturn(mockedConnection);
...
}
The code that I want to test looks like this:
URL wlInvokeUrl = new URL(wlInvokeUrlString);
connection = (HttpURLConnection) wlInvokeUrl.openConnection();
Earlier in my test scenario I mock the wlInvokeUrlString to match "MyURLString". I've also tried using various other forms of the whenNew line, trying to inject the mock. No matter what I try, it never intercepts the constructor. All I want to do is "catch" the call to openConnection() and have it return my mocked HTTP connection instead of the real one.
I have mocked other classes ahead of this one in the same script and these are working as expected. Either I need a second pair of eyes (probably true) or there is something unique about the URL class. I did notice that if I use "whenNew(URL.class).withAnyArguments()" and change the "thenReturn" to "thenAnswer" I could get it to trigger. Only problem is I never get the URL call for my code. What I see is an invocation of the 3-argument constructor for URL.class with all nulls for the parameters. Could it be this class is from the Java runtime and is bootstrapped by the test runner? Any help is much appreciated.
It's a common mistake when use PowerMockito.whenNew.
Note that you must prepare the class creating the new instance of MyClass for test, not the MyClass itself. E.g. if the class doing new MyClass() is called X then you'd have to do #PrepareForTest(X.class) in order for whenNew to work
From Powermock wiki
So, you need a bit change your test and add to #PrepareForTesta class which create a new instance of URLlike:
#RunWith(PowerMockRunner.class)
#PrepareForTest({ URL.class, MockedHttpConnection.class , ConnectionUser.class})
public class URLTest {
public class URLTest {
private ConnectionUser connectionUser;
#Before
public void setUp() throws Exception {
connectionUser = new ConnectionUser();
}
#Test
public void testName() throws Exception {
URL mockedURL = PowerMockito.mock(URL.class);
MockedHttpConnection mockedConnection = PowerMockito.mock(MockedHttpConnection.class);
PowerMockito.whenNew(URL.class).withParameterTypes(String.class).withArguments("MyURLString").thenReturn(mockedURL);
PowerMockito.when(mockedURL.openConnection()).thenReturn(mockedConnection);
connectionUser.open();
assertEquals(mockedConnection, connectionUser.getConnection());
}
}
where:
public class ConnectionUser {
private String wlInvokeUrlString = "MyURLString";
private HttpURLConnection connection;
public void open() throws IOException {
URL wlInvokeUrl = new URL(wlInvokeUrlString);
connection = (HttpURLConnection) wlInvokeUrl.openConnection();
}
public HttpURLConnection getConnection() {
return connection;
}
}
I'm not sure the difference between .withParameterTypes(x) and .withArguments(x) but I believe you need to set it up as follows for your code to work. Give it a try and let me know if this doesn't help.
PowerMockito.when(mockedURL.openConnection()).thenReturn(mockedConnection);
PowerMockito.whenNew(URL.class).withArguments(Mockito.anyString()).thenReturn(mockedURL);
The problem is that the arguments of the real call are not matching with the expected in your mock.
PowerMockito.whenNew(URL.class).withParameterTypes(String.class).withArguments("MyURLString").thenReturn(mockedURL) will return mockedURL only the call is new URL("MyURLString").
If you change it to:
PowerMockito.whenNew( URL.class ).withParameterTypes( String.class )
.withArguments( org.mockito.Matchers.any( String.class ) ).thenReturn( mockedURL );
It will catch any string passed to the constructor URL(String) (even null) and return your mock.
When you tried
"whenNew(URL.class).withAnyArguments()" and change the "thenReturn" to
"thenAnswer" I could get it to trigger. Only problem is I never get
the URL call for my code. What I see is an invocation of the
3-argument constructor for URL.class with all nulls for the
parameters.
PowerMock will try to mock all constructors (org.powermock.api.mockito.internal.expectation.DelegatingToConstructorsOngoingStubbing.InvokeStubMethod at line 122) then it calls the first one (with 3 arguments) and mock its answer. But the subsequent calls will return the already mocked one because you told it to mock for any arguments. That's why you see just one call with null, null, null in your Answer.