Sample code which I tried to mock Appium IOS Driver, It gives Null >Pointer exception
Initializing Driver and AndroidDriver object
Driver driver;
AndroidDriver<AndroidElement> androidDriver;
#SuppressWarnings({ "unchecked" })
#Test
public void getLogAndroid_happyPath() throws Exception{
>Setting logs to mock return type
List<LogEntry> setLogs = new ArrayList<LogEntry>();
setLogs.add(new LogEntry(Level.ALL, 0, "logs"));
driver = new Driver();
Mocking Android Driver with Nice Mock which can result in void
enter code here>return types as well
androidDriver = EasyMock.createNiceMock(AndroidDriver.class);
driver.setAndroidDriver(androidDriver);
EasyMock object call
EasyMock.expect(androidDriver.manage().logs().get(EasyMock.anyString()).getAll()).andReturn(setLogs);
EasyMock.replay(androidDriver);
try {
>Asserting mocked return type
assertTrue(driver.getLog("getLog",5000).contains(setLogs));
} catch (Exception e) {
e.printStackTrace();
}
>Verify EasyMock Object
EasyMock.verify(androidDriver);
EasyMock.reset(androidDriver);
}
You can't do EasyMock.expect(androidDriver.manage().logs().get(EasyMock.anyString()).getAll()).
Even if androidDrive is a mock, it won't cause androidDriver.manage() to return a mock. It will return null. So you probably have a NPE right now.
So you need something like (I'm using a more modern syntax as well):
androidDriver = niceMock(AndroidDriver.class);
what_is_returned_by_manage = mock(WhatIsReturnedByManage.class);
what_is_returned_by_logs = mock(WhatIsReturnedByLogs.class);
what_is_returned_by_get = mock(WhatIsReturnedByGet.class);
expect(androidDriver.manage()).andReturn(what_is_returned_by_manage);
expect(what_is_returned_by_manage.logs()).andReturn(what_is_returned_by_logs);
expect(what_is_returned_by_logs.get(anyString())).andReturn(what_is_returned_by_get);
expect(what_is_returned_by_get.getAll()).andReturn(setLogs);
But actually I would never ever code that. I would add a getAllLogs on what_is_returned_by_manage or something like that.
Related
I want to create an instance of class A which inherits class StatelessService in my unit test. But I can't. I've tried everything: mocking dependencies, implementing my own contexts and etc.
When I try to create an instance, StatelessService throws NullReferenceException somewhere inside.
Can it be done at all?
class A : StatelessService
{
public A(StatelessServiceContext context) : base(context /* Here will be thrown NullReferenceException */)
{
// It will never even get there.
}
}
class UnitTest
{
public void TestMethod()
{
var activationContext = MOCK<ICodePackageActivationContext>();
var context = new StatelessServiceContext(..., activationContext, ...);
var a = new A(context); // Here will be thrown an exception.
}
}
It can be done. But instead of re inventing the wheel, have a look at service fabric mocks https://github.com/loekd/ServiceFabric.Mocks
It contains useful helpers for exactly your type of scenario.
I am assigned to add unit test code coverage to a 15 years old legacy project which is not using IoC and 0 unit test. I am not allowed to refactor the code since it works perfect fine on production, management does not want other teams get involved for refactoring such as QA testing, etc.
Service class has a performService method has following code
public void performService(requestMessage, responseMessage) {
UserAccount userAccount = requestMessage.getUserAccount();
GroupAccount groupAccount = requestMessage.getGroupAccount();
Type type = requestMessage.getType();
StaticServiceCall.enroll(userAccount, groupAccount, type);
response.setStatus(Status.SUCCESS);
}
This StaticServiceCall.enroll method is calling remote service. My unit test is
#RunWith(PowerMockRunner.class)
#PrepareForTest(StaticServiceCall.class)
public class EnrollmentServiceTest {
#Test
public void testPerformService() {
mockStatic(StaticServiceCall.class);
doNothing().when(StaticServiceCall.enroll(any(UserAccount.class), any(GroupAccount.class), any(Type.class)));
service.performService(requestMessage, responseMessage);
assertEquals("Enrollment should be success, but not", Status.SUCCESS, response.getStatus);
}
Eclipse complains with The method when(T) in the type Stubber is not applicable for the arguments (void)
Eclipse stops complain if test code change to
mockStatic(StaticServiceCall.class);
doNothing().when(StaticServiceCall.class);
StaticServiceCall.enroll(any(UserAccount.class), any(GroupAccount.class), any(Type.class));
service.performService(requestMessage, responseMessage);
assertEquals("Enrollment should be success, but not", Status.SUCCESS, response.getStatus);
Test case failed with UnfinishedStubbingException. I am using powermock 1.6.6
There is a misconception on your end. You think that you need to say that doNothing() should do nothing.
That is not necessary! As these lines
#PrepareForTest(StaticServiceCall.class) ... and
mockStatic(StaticServiceCall.class);
are sufficient already.
You want to prevent the "real" content of that static method to run when the method is invoked during your test. And that is what mockStatic() is doing.
In other words: as soon as you use mockStatic() the complete implementation of the real class is wiped. You only need to use when/then/doReturn/doThrow in case you want to happen something else than nothing.
Meaning: just remove that whole doNothing() line!
#GhostCat - Thank you for your answer, it solved problem, my misconception is coming from this test case
#Test
public void testEnrollmentServiceSuccess() {
RequestMessage requestMessage = new RequestMessage();
requestMessage.setName("ENROLL");
ResponseMessage responseMessage = new ResponseMessage();
EnrollmentService mockService = mock(EnrollmentService.class);
mockService.performService(any(RequestMessage.class), any(ResponseMessage.class));
mockStatic(ClientManager.class);
when(ClientManager.isAuthenticated()).thenReturn(true);
ServiceImpl service = new ServiceImpl();
service.performService(requestMessage, responseMessage);
verify(mockService).performService(any(RequestMessage.class), any(ResponseMessage.class));
}
Here is the code snippet of ServiceImpl class based name of the request message calling different service class
public void performService(RequestMessage request, ResponseMessage response) {
try {
if (request == null) {
throw new InvalidRequestFormatException("null message");
}
if (!ClientManager.isAuthenticated()) {
throw new ServiceFailureException("not authenticated");
}
// main switch for known services
if ("ENROLL".equals(request.getName())) {
service = new EnrollmentService();
service.performService(request, response);
} else if ("VALIDATE".equals(request.getName())) {
...
Although the test passed,real implementation in EnrollmentService got called and exceptions thrown due to barebone RequestMessage object, then I googled out doNothing, thanks again for your clarification
I've been working with JMockit and its admittedly steep learning curve. I'm pretty new with mocking in general so please excuse the ignorance.
I'm trying to mock out the Logger interface so that I can verify the catch statement is working correctly. Call this an exercise in understanding how JMockit works. The implementing class for the Logger interface is Log4jLoggerAdapter so I thought if I passed an instance of that into my Expectations() block, JMockit would use dynamic partial mocking and "see" my logger statement. Instead, I get the following error:
mockit.internal.MissingInvocation: Missing invocation of: org.slf4j.impl.Log4jLoggerAdapter#error(String msg, Throwable t)
The Class Being Tested
public class MyLoggedClass {
private static final Logger LOGGER = LoggerFactory.getLogger(MyLoggedClass.class);
... // Other variables
#Override
public void connect() {
String info = getServiceInfo();
try {
connector = MyConnectionFactory.connect(info);
} catch (Exception e) {
LOGGER.error("Exception connecting to your service with: " + info, e);
}
}
... // Other methods
}
My #Test
public class MyLoggedClassTest {
#Tested
MyLoggedClass myLoggedClass;
#Test
public void myLoggingTest(#Mocked final Log4jLoggerAdapter logger){
new Expectations(MyConnectionFactory.class, logger){{
MyConnectionFactory.connect(anyString);
result = new Exception();
logger.error(anyString, (Throwable)any);
}};
myLoggedClass.connect();
}
I'd detail the other approaches I've tried but this page would turn into a book. This is my best approach. Any ideas?
* Update * (yes, that was quick)
I changed #Mocked to #Cascading and removed the logger field from my Expectations signature and it worked. I don't understand why. Can someone please provide an explanation? Fumbling about until you stumble on something that works but you don't understand is not a recipe for success. See below:
#Test
public void myLoggingTest(#Cascading final Log4jLoggerAdapter logger){
new Expectations(MyConnectionFactory.class){{
MyConnectionFactory.connect(anyString);
result = new Exception();
logger.error(anyString, (Throwable)any);
}};
myLoggedClass.connect();
}
No need for partial mocking in this case, just mock MyConnectionFactory in the usual way. The only tricky part is how to mock the class that implements the Logger interface, considering that it's instantiated from a static class initializer. As it happens, there is a feature in the mocking API for that (using JMockit 1.14):
public class MyLoggedClassTest
{
#Tested MyLoggedClass myLoggedClass;
#Test
public void myLoggingTest(
#Mocked MyConnectionFactory conFac,
#Capturing final Logger logger)
{
new Expectations() {{
MyConnectionFactory.connect(anyString);
result = new Exception();
}};
myLoggedClass.connect();
new Verifications() {{
logger.error(anyString, (Throwable)any);
}};
}
}
With a #Capturing mocked type, any implementation class will get mocked, so the test doesn't need to know about Log4jLoggerAdapter.
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 have a class that I want to write unit tests for. I'm using StructureMap (2.6.3) in the project and I have some problems with that.
For testing I use Nunit (2.6.0.12054) and RhinoMocks (3.6).
Normally i inject my dependencies in the constructor of my classes and then it's easy to substitute the dependencies with mocks in my unit tests. But there are a few cases where I can't do that, where I have no control over when the class under test is created. In these cases I use ObjectFactory.GetInstance() to get the dependencies.
public class MyClass
{
public int MyMethod(string parameter)
{
var myDependency = ObjectFactory.GetInstance<IMyDependency>();
try
{
return myDependency.CalculateValue(parameter);
}
catch (Exception ex)
{
//Suppress exception.
return 0;
}
}
}
For this class and method I want to write two tests. First I want to to test that the dependency is called and the value it calculates is returned by the class under test. Second, the dependency might throw an exception and I want to test that this exception is suppressed by the class under test and that it return zero in that case.
[TestFixture]
public class MyClassTests()
{
[Test]
public void MyMethod_DependencyReturnsValue_ReturnsValueFromDependency
{
//Arrange.
const int valueFromDependencyStub = 333;
var myDependencyStub = MockRepository.GenerateStub<IMyDependency>();
myDependencyStub.Stub(x => x.CalculateValue()).Return(valueFromDependencyStub);
ObjectFactory.Inject<IMyDependency>(myDependencyStub);
var target = new MyClass();
//Act.
var result = target.MyMethod("test");
//Assert.
Assert.AreEqual(valueFromDependencyStub, result);
}
[Test]
public void MyMethod_DependencyThrowsException_ReturnsZero
{
//Arrange.
var myDependencyStub = MockRepository.GenerateStub<IMyDependency>();
myDependencyStub.Stub(x => x.CalculateValue()).Throw(new Exception());
ObjectFactory.Inject<IMyDependency>(myDependencyStub);
var target = new MyClass();
//Act.
var result = target.MyMethod("test");
//Assert.
Assert.AreEqual(0, result);
}
}
Both these tests work if I run them individually, but if I run the both it does not work. I my real case the second test, where the stubbed dependency throws an exception, runs first. When the other test runs the stubbed dependency still throws an exception.
The problem, as I understand it, is that I'm using the global ObjectFactory and inject my stub into that. That would probably work if I could clear the ObjectFactory after each test, but I found no way to do that. ObjectFactory.EjectAllInstancesOf() sounded like something that would work, but it doesn't.
How do I solve this? Either by changing my test or by actually rewriting the class under test.