I have an application with following structure:
Client class:
class Client{
private Requests requests;
private Settings settings;
protected Client(Settings settings){
this.settings = settings;
this.requests = new Requests(settings);
}
public Requests getRequests(){
return requests;
}
}
Requests class:
class Requests{
private RequestsHandler requestsHandler;
private Settings settings;
protected Requests(Settings settings){
this.requestHandler = new RequestHandler();
this.settings = settings;
}
public Bicycles getBicycles(BicyclesParameters bicycleParams){
return requestsHandler.callService(bicycleParams, settings, "service/getBicycles", Bicycles.class)
}
}
And my
RequestsHandler class:
class RequestsHandler{
public BaseResponse callService(BaseParams params, Settings settings, String serviceURL, Class<? extends BaseResponse> responseType ) {
here I use RestTemplate to get data from external Service
}
}
In my Unit tests, I would like to mock the data from external service, so I did as following:
create a mocking RequestsHandler object, mock the callService method and register this mock object with #Bean:
#Configuration
public class TestConfiguration {
#Bean
public RequestsHandler requestsHandler() {
RequestsHandler requestsHandler = Mockito.mock(RequestsHandler.class);
when(requestsHandler.callService(new BicyclesParameters(), new Settings(),
"/service/getBicyles", Bicycles.class))
.thenReturn(new Bicycles().setBicyclesList(new Bicycle[] {new Bicycle(), new Bicycle()}));
return requestsHandler;
}
}
and my test class:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = TestConfiguration.class)
public class TestGetBicycles{
#Test
public void testGetBicycles() {
Client = new Client(new Settings);
Bicycles bicycles = client.getRequests.getBicycles(new BicyclesParamters());
assertNotNull(bicycles.getBicyclesList());
}
}
But when I run the test, I had two problems:
I become an
org.mockito.exceptions.misusing.InvalidUseOfMatchersException
, I have no idea why but when I changed my mock object to:
when(requestsHandler.callService(any(), any(),
any(), any()))
.thenReturn(new Bicycles().setBicyclesList(new Bicycle[] {new Bicycle(), new Bicycle()}));
the error went away, but
the result I become is not the mock result, instead the result from the external service. This means the mock object was not taken into account.
Can anyone help me at these points? This is my first time working with Mockito so I am so confused now.
Thank you in advanced!
You create a mock but this is never used in the scope of the executed method.
In fact your problem is that you want to mock an object that is created inside a object created during the invocation of the tested method :
protected Requests(Settings settings){
this.requestHandler = new RequestHandler(); // <- You want to mock this field
this.settings = settings;
}
It is not possible with plain mockito. In your case you have two ways :
1) refactor your code to provide an additional constructor that accepts the RequestHandler as parameter. In your case Client and Requests could accept RequestHandler.
For example for Client :
protected Client(Settings settings, RequestsHandler requestHandler){
this.settings = settings;
this.requests = new Requests(settings, requestHandler);
}
and you test could look like :
#Mock
RequestsHandler requestsHandlerMock;
...
#Test
public void testGetBicycles() {
Client = new Client(new Settings(), requestsHandlerMock);
Bicycles bicycles = client.getRequests.getBicycles(new BicyclesParamters());
//...
}
2) Using libraries that relies on reflection and byte code generation (as CGLib) at runtime. PowerMock and PowerMockito are well known in Java for that.
Personally I favor the refactoring as it is possible. It makes the code always clearer and cleaner. In fact these libraries are not bad in themselves but it may create some technical debt as by using them too often you may be encouraged to cheat with the help of the library instead of improving the API of the code to test.
Related
I have a service class, with for readability purpose, I have provided the code with dummy variables and objects. I am trying to write a JUNIT test class for the service, primarily with Mockito. No matter how hard I try, I am not able to hit the method serviceMethod irrespective of using spy/mock. I have also included a test, following the main class.
I know I am missing something here, but doesn't cross my mind. I need an eye to review this and let me know how I can write a proper test class for this and obtain coverage for the method.
(P.S. all the necessary imports are in-place and not pasted here to keep this concise)
Thanks in advance!
#Service
public class ServiceClass {
private static final Logger LOGGER = LoggerFactory.getLogger(ServiceClass.class);
#Autowired
String stringUrl;
RestTemplate restTemplate = new RestTemplate();
public void serviceMethod(ModelObject model) {
try {
HttpEntity<ModelObject> request = new HttpEntity<>(model);
ResponseEntity<String> response = restTemplate.exchange(stringUrl,
HttpMethod.POST, request, String.class);
LOGGER.info(response.getBody() + "and " + response.getStatusCode());
} catch (HttpClientErrorException exception) {
LOGGER.info(exception.getResponseBodyAsString());
} catch (HttpStatusCodeException exception) {
LOGGER.info(exception.getResponseBodyAsString());
}
}
Sample Test:
#RunWith(MockitoJUnitRunner.Silent.class)
public class ServiceClassTest {
#InjectMocks
private ServiceClass serviceClass;
#Mock
private RestTemplate restTemplate;
#Test
public void testServiceMethod() {
ServiceClass spy = Mockito.spy(serviceClass);
// ServiceClass spy = mock(ServiceClass.class, Mockito.CALLS_REAL_METHODS);
doNothing().when(spy).serviceMethod(Mockito.any(ModelObject.class));
Mockito.doCallRealMethod().when(spy).serviceMethod(Mockito.any(ModelObject.class));
ResponseEntity<String> responseEntity = new ResponseEntity<>(HttpStatus.ACCEPTED);
Mockito.when(restTemplate.exchange(ArgumentMatchers.anyString(), ArgumentMatchers.any(HttpMethod.class),
ArgumentMatchers.<HttpEntity<ModelObject>>any(), ArgumentMatchers.<Class<String>>any()))
.thenReturn(responseEntity);
}
I am using Mockito to write a simple unit test.
Then, a function under test:
public class MyService {
public void getData() {
executor.execute(new MyRunnable() {
#Override
doTask() {
MyRestClient client = getRestClient();
Response resp = client.getFromServer();
persist(resp.getData());
}
});
}
}
protected MyRestClient getRestClient() {
return new MyRestClient();
}
My test case, I want to test doTask() has run & resp.getData() is persisted:
#Test
public void testGetData() {
MyService spyService = spy(MyService.getInstance());
// mock client
MyRestClient mockedClient = mock(MyRestClient.class);
mockedClient.setData("testData");
// stub getRestClient() function to return mocked client
when(spyService.getRestClient()).thenReturn(mockedClient);
// SUT
spyService.getData();
// run the Runnable task.
Mockito.doAnswer(new Answer<Object>() {
public Object answer(InvocationOnMock invocation) throws Exception {
Object[] args = invocation.getArguments();
Runnable runnable = (Runnable) args[0];
runnable.doTask();
return null;
}
}).when(executor).execute(Mockito.any(Runnable.class));
...
}
As you see above, I stub the getRestClient() function to return a mocked MyRestClient. However when run the test case, it doesn't stub the getRestClient() but run the real function. Why?
[Edit] following comment and review feedback
A rule of thumb is not to mock the class under test. Also your testing will be much easier if your class under test does not use the new keyword. Instead use Factory classes to create objects. There will be no need to use Mockito.spy() only Mockito.mock().
The fact that the following answer requires significant test setup is telling you that MyService has too much reposibility and needs to be simplified. However for the sake of answering your question directly here is how you can refactor your code to support verifying the call to persist() using Mocks.
MyService accepts in the constructor the objects that you will be mocking in your test setup. Having them passed into the constructor allows your JUnit test case to create the Mocks and keep a reference to them for verification later.
public class MyService {
private MyRunnableFactory runFactory;
private MyRestClientFactory restFactory;
private MyRestDao dao;
// inject constructor arguments
public MyService(MyRunnableFactory runFactory, MyRestClientFactory restFactory, MyRestDao dao) {
this.runFactory = runFactory;
this.restFactory = restFactory;
this.dao = dao;
}
public void getData() {
MyRestClient restClient = restFactory.createInstance();
MyRunnable runner = runFactory.createInstance(restClient, dao);
executor.execute(runner);
}
}
MyRunnable is created so that it can be tested in isolation if required. Again we inject the Mock objects into the constructor. It is tempting to inline Runnables as you have written in your question, however you lose the ability to control the new instance being created within you tests.
public class MyRunnable implements Runnable {
private MyRestClient restClient;
private MyRestDao dao;
public MyRunnable(MyRestClient restClient, MyRestDao dao) {
this.restClient = restClient;
this.dao = dao;
}
public void run() {
Response resp = restClient.getFromServer();
dao.persist(resp.getData());
}
}
MyRestDao is created because this is the class that you want to Verify in your test case. I don't see where persist() is defined in your question so we create a Data Access Object (DAO) to implement it.
public class MyRestDao {
public void persist() {
// save to some repository
}
}
Now let's write the test case that uses the above classes. We want to verify that the persist() method has been called
#RunWith(MockitoJUnitRunner.class)
public class MyServiceTest {
#Mock MyRestDao dao;
#Mock MyRestClient restClient;
#Mock MyRunnableFactory runFactory;
#Mock MyRestClientFactory restFactory;
#Test
public void testPersistIsCalled() {
Response expectedResponse = new Response("some data"); // real implementation, not mocked
MyRunnable runner = new MyRunnable(restClient, dao); // real implementation, not mocked
when(restFactory.createInstance()).thenReturn(restClient);
when(runFactory.createInstance(restClient, dao)).thenReturn(runner);
when(restClient.getFromServer()).thenReturn(expectedResponse);
when(restClient.getData()).thenReturn(myRunnable);
// method under test
MyService service = new MyService(runFactory, restFactory);
service.getData();
verify(dao).persist(expectedResponse.getData());
}
}
Note that this test case is brittle because it is tightly coupled to the actual implementation of the MyService class. Ideally you want tests that don't need to know about the internal workings of your class under test.
I am a Dagger newbie.
TL;DR:
If an Android Service has any fields injected into it using Dagger, then in order to actually perform the injection, I need to have an instance of that Service.
In Robolectric tests, this corresponds to MyService service = Robolectric.buildService(MyService.class).get(). And then, objectGraph.inject(service);
However, rest of the code that actually starts MyService still uses context.startService(context, MyService.class);.
Question: What is the idiomatic way in Dagger to address this mismatch?
Let's say I have a Service as follows:
public class MyService {
#Inject Parser parser;
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
String data = intent.getStringExtra("data_to_be_parsed");
parser.parse(data);
}
}
Elsewhere in my code, I have an ApiClient class that does this:
public class ApiClient{
public static void parseInBackground(Context context, String data){
//This service does not have its fields injected
context.startService(new Intent(context, MyService.class).putExtra("data_to_be_parsed", data));
}
}
That parseInBackground method will be called from an Activity in response to user interaction.
Now, I'm following TDD and hence, I haven't yet written the Application Module for this. Here's the test module:
#Module(injects = MyService.class)
public class TestModule {
#Provides #Singleton Parser provideParser(){
return new MockParser();
}
}
And finally, the test case:
#RunWith(Robolectric.class)
public class ApiTest {
#Test
public void parseInBackground_ParsesCorrectly(){
//This service has its fields injected
MyService service = Robolectric.buildService(MyService.class).get();
ObjectGraph.create(new TestModule()).inject(service);
ApiClient.parseInBackground(Robolectric.application, "<user><name>droid</name></user>");
//Asserts here
}
}
As you can see, in the test, I retrieve an instance of the service and then inject the MockParser into it. However, the ApiClient class directly starts the service using an Intent. I don't have a chance to perform the injection.
I am aware that I can have MyService perform an injection on itself:
public void onCreate(){
ObjectGraph.create(new TestModule()).inject(this);
}
But then, I am hardcoding the TestModule here.
Is there an existing idiom in Dagger to set up dependencies for such situations?
It's the wrong way to hardcode your modules either in tests or in services. Better approach is to perform creation via your custom Application object which in turn will hold singleton ObjectGraph object. For example:
// in MyService class
#Override public void onCreate() {
super.onCreate();
MyApp.from(context).inject(this);
}
// in MyApp class
public static MyApp from(Context context) {
return (MyApp) context.getApplicationContext();
}
//...
private ObjectGraph objectGraph;
#Override public void onCreate() {
// Perform Injection
objectGraph = ObjectGraph.create(getModules());
objectGraph.inject(this);
}
public void inject(Object object) {
objectGraph.inject(object);
}
protected Object[] getModules() {
// return concrete modules based on build type or any other conditions.
}
Alternatively, you can refactor last method out into separate class and make different implementations for different flavors or build types. Also you may want to set overrides=true in your TestModule's annotation.
How is it possible to produce the same exception like during a real connection-error in robolectric tests?
I want to how the program acts if the network is currently not available. Is there a possibility to produce the same exception for my HttpClient?
I already tried:
Robolectric.getFakeHttpLayer().interceptHttpRequests(false); // with real network to a non existent IP
and
WifiManager wifiManager = (WifiManager) activity.getSystemService(Context.WIFI_SERVICE);
wifiManager.setWifiEnabled(false);
and
Robolectric.addPendingHttpResponse(404, null);
but none of them produces the same reactions like a real connection-loosing.
Thank you
I've checked Robolectric's FakeHttpLayer and haven't found way to simulate throwing an IOException.
So use mocking to make it working for you. First introduce HttpClientFactory (if you use HttpClient, you can use same approach for HttpUrlConnection):
public class HttpClientFactory {
public HttpClient createClient() {
return new DefaultHttpClient();
}
}
And now in your networking layer use factory instead of constructors (let for simplicity assume that it is synchronous):
public class HttpTransportLayer {
private final HttpClientFactory clientFactory;
public HttpTransportLayer() {
this(new HttpClientFactory());
}
// For tests only
HttpTransportLayer(HttpClientFactory clientFactory) {
this.clientFactory = clientFactory;
}
public String requestData(String url) {
HttpClient client = factory.createClient();
...
}
}
So now you can in tests use Mockito:
HttpClient mockedClient = mock(HttpClient.class);
#Before
public void setUp() {
HttpClientFactory factory = mock(HttpClientFactory.class);
when(factory.createClient()).thenReturn(mockedClient);
target = new HttpTransportLayer(factory);
}
#Test
public void whenIOExceptionThenReturnNull() {
when(mockedClient.execute(any(HtptUriRequest.class))).thenThrow(new IOException());
String data = target.requestData("http://google.com");
assertThat(data).isNull();
}
That is dummy test and usually nobody will return null in case of error.
You could also task look to some dependency injection framework like Dagger to minimise injection code.
If you use any good framework for networking like Retrofit or Volley then it is even simpler - you don't need to mock anything and just invoke you error callback.
Hope it helps
I'm trying to test my Session Beans with JUnit, but I can't. I've tried a lot of method, but still get some exceptions.
Here is what I need:
I have a few Stateless Session Beans I need to test. Each has the same #PersistenceContext and uses an EntityManager
With my test cases I need to test their methods. For instance: if I add an user with username X and then I try to add another one with the same username, I want to catch an Exception.
Can someone provide a simple and short generic test example? I've already read many, but I always get an error (I get NullPointerException for the EntityManager when I call a method like: sessionBean.method() (which does, for instance, entityManager.find(...)), or I am not able to initialize the Context, or other PersistenceException).
You might be interested in one of the latest posts of Antonio Goncalves:
WYTIWYR : What You Test Is What You Run
It tells about testing EJB with EntityManager using:
Mockito,
Embedded EJB Container,
Arquillian.
I solved creating a Stateless Session Bean and injecting its Entity Manager to test classes. I post the code in case someone will need it:
#Stateless(name = "TestProxy")
#Remote({TestProxyRemote.class})
public class TestProxy implements TestProxyRemote {
#PersistenceContext(unitName = "mph")
private EntityManager em;
#Override
public void persist(Object o) {
em.persist(o);
}
#Override
public void clear() {
em.clear();
}
#Override
public void merge(Object o) {
em.merge(o);
}
#Override
#SuppressWarnings({ "rawtypes", "unchecked" })
public Object find(Class classe, String key) {
return em.find(classe, key);
}
#Override
#SuppressWarnings({ "rawtypes", "unchecked" })
public Object find(Class classe, long key) {
return em.find(classe, key);
}
#SuppressWarnings("rawtypes")
#Override
public List getEntityList(String query) {
Query q = em.createQuery(query);
return q.getResultList();
}
}
public class MyTest {
#BeforeClass
public static void setUpBeforeClass() throws NamingException {
Properties env = new Properties();
env.setProperty(Context.INITIAL_CONTEXT_FACTORY,"org.jnp.interfaces.NamingContextFactory");
env.setProperty(Context.PROVIDER_URL, "localhost:1099");
env.setProperty("java.naming.factory.url.pkgs","org.jboss.naming:org.jnp.interfaces");
jndiContext = new InitialContext(env);
try {
proxy = (TestProxyRemote) jndiContext.lookup("TestProxy/remote");
} catch (NamingException e) {
e.printStackTrace();
}
}
}
Then I can use proxy.find() to get the entities I need, o proxy.getEntityList() to execute a query to retrieve all the instance of an Entity. Or I can add other methods if I want.
Unitils provides a really cool support for JPA. Unitils can be used with JUnit or TestNG and in case you need a mocking framework, Unitils provides its own mocking module as well as support for EasyMock.
#JpaEntityManagerFactory(persistenceUnit = "testPersistenceUnit")
#DataSet(loadStrategy = RefreshLoadStrategy.class)
public class TimeTrackerTest extends UnitilsTestNG {
#TestedObject
private TimeTrackerBean cut = new TimeTrackerBean();
#InjectInto(target="cut",property="em")
#PersistenceContext
private EntityManager em;
#Test
#DataSet("TimeTrackerTest.testAddTimeSlot.xml")
public void yourTest() {
...
}
}
#JpaEntityManagerFactory - Used to specify your persistence unit. It automatically picks up the persistence.xml from your project classpath.
#DataSet - Just in case you need to load any test data you can use this.
#TestedObject - Marks your Class Under Test
#PersistenceContext - Automatically creates your EntityManager instance from the configurations made in the persistence.xml - PersistenceUnit.
#InjectInto - Injects the em instance into the target (cut)
For more information refer this.
Hope this helps.
I'm using Needle for this. It works well with Mockito and EasyMock if you want to mock other objects.
First I write a persistencte.xml for tests (src/test/resources/META-INF) like this:
<persistence-unit name="rapPersistenceTest" transaction-type="RESOURCE_LOCAL">
<properties>
<property name="javax.persistence.jdbc.driver" value="org.h2.Driver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:h2:~/test"/>
...
</properties>
</persistence-unit>
In my Junit-Testclass I write:
public class DaoNeedleTest {
//here Needle will create persistenceContext for your testclass
public static DatabaseRule databaseRule = new DatabaseRule("rapPersistenceTest");
//here you can get the entityManager to manipulate data directly
private final EntityManager entityManager = databaseRule.getEntityManager();
#Rule
public NeedleRule needleRule = new NeedleRule(databaseRule);
//here you can instantiate your daoService
#ObjectUnderTest
DAOService daoService;
#Test
public void test() {
//if your method needs a transaction here you can get it
entityManager.getTransaction().begin();
daoService.yourMethod();
entityManager.getTransaction().commit();
}
You also need a Needle-configuration File in src/test/resources, where you tell what kind of Mock-provider you are using. E.g. I'm using Mockito:
mock.provider=de.akquinet.jbosscc.needle.mock.MockitoProvider
That's it.