Hi I am getting Null Pointer Exception while trying to write unit test cases
Here is the class detail:
public CreateDraftCampaignResponse createDraftCampaign(CreateDraftCampaignRequest request) throws InvalidInputsException,
DependencyException, UnauthorizedException {
CreateDraftCampaignResponse draftCampaignResponse = null;
try {
DraftCampaignDetails createdDraft = draftCampaignI.createDraftCampaign(ConvertionUtil
.getDraftCampaignDetailsfromCreateDraftRequest(request));
draftCampaignResponse = new CreateDraftCampaignResponse();
draftCampaignResponse.setDraftCampaignId(createdDraft.getDraftId());
}
catch (Exception e) {
log.error("Create Draft Campaign Exception", e);
throw e;
}
return draftCampaignResponse;
}
This is the ConvertionUtil class:
public static DraftCampaignDetails getDraftCampaignDetailsfromCreateDraftRequest(CreateDraftCampaignRequest request) {
DraftCampaignDetails draftCampaign = new DraftCampaignDetails();
DraftCampaignDetailsBase draftCampaignDetailsBase = request
.getDraftCampaignDetailsBase(); (This is giving exception)
draftCampaign.setCampaignBudget(draftCampaignDetailsBase
.getCampaignBudget());
draftCampaign.setCampaignName(draftCampaignDetailsBase
.getCampaignName());
draftCampaign.setDraftCampaignState(draftCampaignDetailsBase
.getDraftCampaignState());
draftCampaign.setCreatedUser(request.getUser());
draftCampaign.setObfuscatedEntityId(request.getObfuscatedEntityId());
draftCampaign.setCampaignInfo(request.getCampaignInfo());
return draftCampaign;
}
Thsi is what I tried:
#Test
public void createDraft_newDraft() {
DraftCampaignActivity draftContoller = new DraftCampaignActivity();
CreateDraftCampaignRequest request = createRequest();
DraftCampaignDetails details = buildDraftDetails();
if(draftCampaignI == null){
System.out.println("sccdscscd");
}
//ConvertionUtil action1 = PowerMockito.mock(ConvertionUtil.class);
//PowerMockito.when(action1.getDraftCampaignDetailsfromCreateDraftRequest(request)).thenReturn(details);
when(util.getDraftCampaignDetailsfromCreateDraftRequest(request)).thenReturn(details);
when(draftCampaignI.createDraftCampaign(details)).thenReturn(details);
CreateDraftCampaignResponse response = new CreateDraftCampaignResponse();
draftContoller.createDraftCampaign(request);
response.setDraftCampaignId(details.getDraftId());
Assert.assertEquals(response.getDraftCampaignId(),"ww");
}
I am getting NPE. I am a novice in Mockito and other framework. Please help!
It doesn't work because you try to mock a static method and you don't do it properly such that it calls the real method which leads to this NPE in your case.
To mock a static method using Powermock, you need to:
Use the #RunWith(PowerMockRunner.class) annotation at the class-level of the test case.
Use the #PrepareForTest(ClassThatContainsStaticMethod.class) annotation at the class-level of the test case.
Use PowerMock.mockStatic(ClassThatContainsStaticMethod.class) to mock all methods of this class.
So in your case, you should have something like:
#RunWith(PowerMockRunner.class)
public class MyTestClass {
#Test
#PrepareForTest(ConvertionUtil.class)
public void createDraft_newDraft() {
...
PowerMockito.mockStatic(ConvertionUtil.class);
PowerMockito.when(
ConvertionUtil.getDraftCampaignDetailsfromCreateDraftRequest(request)
).thenReturn(details);
...
}
More details about How to mock a static method with Powermock.
Related
I am developing a testing library for Kafka, Kafkaesque. The library lets you develop integration tests for Kafka using a fluid and elegant (?!) API. For now, I develop the version for Spring Kafka.
The library needs to be initialized in every test:
#Test
void consumeShouldConsumeMessagesProducesFromOutsideProducer() {
kafkaTemplate.sendDefault(1, "data1");
kafkaTemplate.sendDefault(2, "data2");
new SpringKafkaesque(broker)
.<Integer, String>consume()
.fromTopic(CONSUMER_TEST_TOPIC)
.waitingAtMost(1L, TimeUnit.SECONDS)
.waitingEmptyPolls(5, 100L, TimeUnit.MILLISECONDS)
.withDeserializers(new IntegerDeserializer(), new StringDeserializer())
.expecting()
.havingRecordsSize(2)
.assertingThatPayloads(Matchers.containsInAnyOrder("data1", "data2"))
.andCloseConsumer();
}
Instead of manually initializing the SpringKafkaesque object, I want to create an annotation that does the magic for me. Something like the #EmbeddedKafka annotation of Spring Kafka.
#SpringBootTest(classes = {TestConfiguration.class})
#Kafkaesque(
topics = {SpringKafkaesqueTest.CONSUMER_TEST_TOPIC, SpringKafkaesqueTest.PRODUCER_TEST_TOPIC})
class SpringKafkaesqueTest {
#Autowired
private Kafkaesque kafkaesque;
#Test
void consumeShouldConsumeMessagesProducesFromOutsideProducer() {
kafkaTemplate.sendDefault(1, "data1");
kafkaTemplate.sendDefault(2, "data2");
kafkaesque
.<Integer, String>consume()
.fromTopic(CONSUMER_TEST_TOPIC)
.waitingAtMost(1L, TimeUnit.SECONDS)
.waitingEmptyPolls(5, 100L, TimeUnit.MILLISECONDS)
.withDeserializers(new IntegerDeserializer(), new StringDeserializer())
.expecting()
.havingRecordsSize(2)
.assertingThatPayloads(Matchers.containsInAnyOrder("data1", "data2"))
.andCloseConsumer();
}
Is it possible? Any suggestion?
JUnit 4
One possible solution is to create a custom annotation processing using reflection. You can get the test method name with #Rule, so for example:
public class CustomAnnotationTest {
private SpringKafkaesque kafkaesqueInstance;
#Rule
public TestName testName = new TestName();
#Before
public void init() {
Method method = null;
try {
method = this.getClass().getMethod(testName.getMethodName());
} catch (Exception ex) {
// handle exceptions
}
if (method.isAnnotationPresent(EmbeddedKafka.class)) {
// Init your SpringKafkaesque instance here
// kafkaesqueInstance = new SpringKafkaesque(broker)
//
}
}
#EmbeddedKafka
#Test
public void testCustomAnnotated() {
// your test here
}
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.METHOD)
#interface EmbeddedKafka {
}
}
You need to store this instance in the class-level variable. For the methods with no #EmbeddedKafka annotation, this variable will be null.
JUnit 5
With JUnit 5 you may consider using parameter injection with ParameterResolver. First of all, you need to implement this interface:
public class KafkaesqueResolver implements ParameterResolver {
#Override
public boolean supportsParameter(ParameterContext parameterContext,
ExtensionContext extensionContext) throws ParameterResolutionException {
return parameterContext.getParameter().getType() == SpringKafkaesque.class;
}
#Override
public Object resolveParameter(ParameterContext parameterContext,
ExtensionContext extensionContext) throws ParameterResolutionException {
// Create an instance of SpringKafkaesque here and return it
return new SpringKafkaesque();
}
}
Next, add #ExtendWith(KafkaesqueResolver.class) annotation to your test class, and add a parameter to your test method, where you need the instance of SpringKafkaesque:
#ExtendWith(KafkaesqueResolver.class)
public class ParamInjectionTest {
#Test
public void testNoParams() {
// nothing to inject
}
#Test
public void testWithParam(SpringKafkaesque instance) {
// do what you need with your instance
}
}
No custom annotation required in this case.
I am writing unit test case for a Class
public class CurrentMoreInfoDataProvider implements CurrentMoreInfoInterface.presenterToModel{
private CurrentMoreInfoInterface.modelToPresenter modelToPresenter;
public CurrentMoreInfoDataProvider(CurrentMoreInfoInterface.modelToPresenter modelToPresenter) {
this.modelToPresenter = modelToPresenter;
}
#Override
public void provideData() {
WeatherApiResponsePojo apiWeatherData = WeatherDataSingleton.getInstance().getApiWeatherData();
if(null != apiWeatherData.getCurrently()){
CurrentlyPojo currently = apiWeatherData.getCurrently();
if(null != currently){
populateWeatherData(currently);
}
}
}
public void populateWeatherData(CurrentlyPojo currently) {....}
I want to just use verify method of power mock to test whether populateWeatherData get executed or not. Below is my test case so far.
#RunWith(PowerMockRunner.class)
#PrepareForTest(CurrentMoreInfoDataProvider.class)
public class TestCurrentMoreInfoDataProvider {
private CurrentMoreInfoDataProvider dataProvider;
#Mock
CurrentMoreInfoInterface.modelToPresenter modelToPresenter;
private CurrentlyPojo currentlyPojo = new CurrentlyPojo();
#Test
public void testPopulateWeatherData(){
dataProvider = PowerMockito.spy(new CurrentMoreInfoDataProvider(modelToPresenter));
dataProvider.provideData();
Mockito.verify(dataProvider).populateWeatherData(currentlyPojo);
}
}
If I run this I get null pointer exception in provideData method at
if(null != apiWeatherData.getCurrently()){
How should I provide apiWeatherData to provideData method in that class?
You have to mock WeatherDataSingleton.getInstance().getApiWeatherData() too.
This would be much easier if you would not use static access in general and the Singelton pattern in particular.
I tried mocking it, but how should i provide that mock object to provideData() ?
create a mock of WeatherDataSingleton.
Configure your Test so that this mock is used (by properly using dependency injection or by surrendering to your bad design using Powermock).
configure the mock to return the data:
doReturn(currentlyPojo).when(weatherDataSingletonMock).getApiWeatherData();
This resolves the NPE.
I dont think you need to go for PowerMockito if you apply a simple refactor to your production code:
public class CurrentMoreInfoDataProvider{
#Override
public void provideData() {
WeatherApiResponsePojo apiWeatherData = getApiWeatherData();
if(null != apiWeatherData.getCurrently()){
CurrentlyPojo currently = apiWeatherData.getCurrently();
if(null != currently){
populateWeatherData(currently);
}
}
}
WeatherApiResponsePojo getApiWeatherData(){
return WeatherDataSingleton.getInstance().getApiWeatherData();
}
then in your test expect that new method to return certain object:
#RunWith(MockitoJUnitRunner.class)
public class TestCurrentMoreInfoDataProvider {
private CurrentMoreInfoDataProvider dataProvider;
#Mock
CurrentMoreInfoInterface.modelToPresenter modelToPresenter;
#Mock
WeatherApiResponsePojo apiWeatherDataMock;
private CurrentlyPojo currentlyPojo = new CurrentlyPojo();
#Test
public void testPopulateWeatherData(){
dataProvider = PowerMockito.spy(new CurrentMoreInfoDataProvider(modelToPresenter));
doReturn(apiWeatherDataMock).when(dataProvider).getApiWeatherData();
dataProvider.provideData();
Mockito.verify(dataProvider).populateWeatherData(currentlyPojo);
}
}
Iam using mockito to perform testing and iam very much new to it.
Iam getting a null pointer exception in the Mockito method and in the Onmessage method for the use of a object/variable declared.
The code snippet is as below.
Class A.java
Class A{
#Inject
CheckConnection connection;
public void onMessage(Message m)
{
if(connection.IsInternetavailable==true) //Null pointer is occuring here
{
//Do something with Message
}
else
{
//Do something with Message
}
}
}
Class Atest.java-Mockito Class
Class ATest
{
#InjectMocks
A resource;
#Mock
CheckConnection connection;
#Test
public void shouldProcessMessage() throws JMSException {
// Arrange
final String Type = "MessageType";
final String Body = "MessageBody"
final ActiveMQTextMessage message = new ActiveMQTextMessage();
message.setStringProperty("messageType", Type);
message.setText(Body);
// Act
this.resource.onMessage(message); //This method fails i.e. it gives null pointer exception
}
}
First: the annotation is InjectMocks not InjectMock s is missing
Second: You need to initialize the mocks with this call MockitoAnnotations.initMocks(this); which should be in your set up method or first call in your test method.
It's useful to test exception handling. In this specific case, I have a extractor that will do a specific task when an exception is thrown while unmarshaling a specific class.
Example Code
Below is a simplified example of the code. The production version is much more complicated.
public class Example {
public static enum EntryType {
TYPE_1,
TYPE_2
}
public static class Thing {
List<String> data = new ArrayList<String>();
EnumSet<EntryType> failedConversions = EnumSet.noneOf(EntryType.class);
}
public static class MyHelper {
public String unmarshal(String input) throws UnmarshalException {
// pretend this does more complicated stuff
return input + " foo ";
}
}
public static class MyService {
MyHelper adapter = new MyHelper();
public Thing process() {
Thing processed = new Thing();
try {
adapter.unmarshal("Type 1");
} catch (UnmarshalException e) {
processed.failedConversions.add(EntryType.TYPE_1);
}
// do some stuff
try {
adapter.unmarshal("Type 2");
} catch (UnmarshalException e) {
processed.failedConversions.add(EntryType.TYPE_2);
}
return processed;
}
}
}
Things I've Tried
Here's a list of things I've tried. For brevity, I haven't filled in all the mundane details.
Spying
The following method doesn't do anything and the exception doesn't throw. I'm not sure why.
#Test
public void shouldFlagFailedConversionUsingSpy()
throws Exception {
MyHelper spied = spy(fixture.adapter);
doThrow(new UnmarshalException("foo")).when(spied).unmarshal(
Mockito.eq("Type 1"));
Thing actual = fixture.process();
assertEquals(1, actual.failedConversions.size());
assertThat(actual.failedConversions.contains(EntryType.TYPE_1), is(true));
}
Mocking
The following didn't work because partial mocks don't seem to play well with methods that throw exceptions.
#Test
public void shouldFlagFailedConversionUsingMocks()
throws Exception {
MyHelper mockAdapter = mock(MyHelper.class);
when(mockAdapter.unmarshal(Mockito.anyString())).thenCallRealMethod();
when(mockAdapter.unmarshal(Mockito.eq("Type 2"))).thenThrow(
new UnmarshalException("foo"));
Thing actual = fixture.process();
assertEquals(1, actual.failedConversions.size());
assertThat(actual.failedConversions.contains(EntryType.TYPE_2), is(true));
}
ThenAnswer
This works, but I'm not sure if it's the proper way to do this:
#Test
public void shouldFlagFailedConversionUsingThenAnswer() throws Exception {
final MyHelper realAdapter = new MyHelper();
MyHelper mockAdapter = mock(MyHelper.class);
fixture.adapter = mockAdapter;
when(mockAdapter.unmarshal(Mockito.anyString())).then(
new Answer<String>() {
#Override
public String answer(InvocationOnMock invocation)
throws Throwable {
Object[] args = invocation.getArguments();
String input = (String) args[0];
if (input.equals("Type 1")) {
throw new UnmarshalException("foo");
}
return realAdapter.unmarshal(input);
}
});
Thing actual = fixture.process();
assertEquals(1, actual.failedConversions.size());
assertThat(actual.failedConversions.contains(EntryType.TYPE_1), is(true));
}
Question
Although the thenAnswer method works, it doesn't seem to be the proper solution. What is the correct way to perform a partial mock for this situation?
I'm not quite sure what you were getting at with the mocking and the spying, but you only really need to mock here.
First, I ran into a few snags when trying your mocks out for whatever reason. I believe this had to do with the spy call which was messed up in some way. I did eventually overcome these, but I wanted to get something simple to pass.
Next, I did notice something off with the way you were spying (the basis of my approach):
MyHelper spied = spy(fixture.adapter);
This implies that you want an instance of MyHelper mocked out, not spied. The worst part is that even if this object were fully hydrated, it wouldn't be properly injected since you haven't reassigned it to the test object (which I presume is fixture).
My preference is to use the MockitoJUnitRunner to help with the injection of mocked instances, and from there I build up a basis of what it is I actually need to mock.
There's only one mocked instance and then the test object, and this declaration will ensure that they're both instantiated and injected:
#RunWith(MockitoJUnitRunner.class)
public class ExampleTest {
#Mock
private MyHelper adapter;
#InjectMocks
private MyService fixture;
}
The idea is that you're injecting your mock into the fixture. You don't have to use this - you could use standard setters in a #Before declaration, but I prefer this since it greatly reduces the boilerplate code you have to write to get mocking to work.
Now there's only one change to be made: remove the spy instance and replace its previous usage with the actual mock.
doThrow(new UnmarshalException("foo")).when(adapter).unmarshal(eq("Type 1"));
With all of the code hoisted, this passes:
#RunWith(MockitoJUnitRunner.class)
public class ExampleTest {
#Mock
private MyHelper adapter;
#InjectMocks
private MyService fixture;
#Test
public void shouldFlagFailedConversionUsingSpy()
throws Exception {
doThrow(new UnmarshalException("foo")).when(adapter).unmarshal(eq("Type 1"));
Thing actual = fixture.process();
assertEquals(1, actual.failedConversions.size());
assertThat(actual.failedConversions.contains(Example.EntryType.TYPE_1), is(true));
}
}
Not being one to want to leave the question/use case incomplete, I circled around and replaced the test with the inner classes, and it works fine too:
#RunWith(MockitoJUnitRunner.class)
public class ExampleTest {
#Mock
private Example.MyHelper adapter;
#InjectMocks
private Example.MyService fixture;
#Test
public void shouldFlagFailedConversionUsingSpy()
throws Exception {
doThrow(new UnmarshalException("foo")).when(adapter).unmarshal(eq("Type 1"));
Example.Thing actual = fixture.process();
assertEquals(1, actual.failedConversions.size());
assertThat(actual.failedConversions.contains(Example.EntryType.TYPE_1), is(true));
}
}
I want the closeSession() method to throw an Exception when it is called so that I can test to see my logging is being done. I have mocked the Crypto object as mockCrypto and set it up as follows:
#Test
public void testdecrpyMcpDataExceptions() throws Exception {
Crypto mockCrypto = Mockito.mock(Crypto.class);
try {
mockCrypto = CryptoManager.getCrypto();
logger.info("Cyrpto Initialized");
} finally {
logger.info("Finally");
try {
logger.info("About to close Crypto!");
Mockito.doThrow(new CryptoException("")).when(mockCrypto).closeSession();
mockCrypto.closeSession();
} catch (CryptoException e) {
logger.warn("CryptoException occurred when closing crypto session at decryptMcpData() in CipherUtil : esi");
}
}
}
However when I run it I get the error :
Argument passed to when() is not a mock!
Am I mocking the class wrong or am I just missing something?
don't you overwrite your mock at
mockCrypto = CryptoManager.getCrypto();
Tested
#Test(expected=RuntimeException.class)
public void testdecrpyMcpDataExceptions() throws Exception {
Crypto mockCrypto = mock(Crypto.class);
doThrow(new RuntimeException()).when(mockCrypto).closeSession();
mockCrypto.closeSession();
}
works fine.
this line is overwriting your mock:
mockCrypto = CryptoManager.getCrypto();
and thats why it fails.