RxJava, How can I write test code for disposable.clear()? - unit-testing

I am developing an Android app.
My app is based on the MVP pattern.
So when the Activity's lifecycle is terminated, the presenter's unsubscribe() function is called.
The unsubscribe() function just clear 'disposable'.
It's very simple code like below:
override fun unsubscribe() {
disposable.clear()
}
The unsubscribe() function is very simple, so I have not tested it before.
But today, I just want to increase the code coverage.
So I tried to write test code for this function.
My first try is:
#Test
fun unsubscribeTest() {
mPresenter.unsubscribe()
verify(mockDisposable).clear()
}
But I didn't know the clear() function is the function of CompositeDisposable class, not Disposable interface.
So I cannot use it as a mock.

I solved this using disposable.size().
I changed the disposable to settable/injectable.
So the result is:
#Test
fun unsubscribeTest() {
val d = CompositeDisposable()
mPresenter.disposable = d
assertEquals(0, mPresenter.disposable.size())
d.add(Observable.just("").subscribe())
assertEquals(1, mPresenter.disposable.size())
mPresenter.unsubscribe()
assertEquals(0, mPresenter.disposable.size())
}

Related

How to mock kotlin object for unit testing

I have a sample method(which I need to write test case) as given below,
fun setName(val auxName:String) {
val configUrl = getConfig(auxName)
}
I want to mock the getConfig method and return a specific string value.
getConfig is a method in a Kotlin Object as below,
object Configuration{
fun getConfig(auxName:String){
....
}
}
Below is the test that I tried
#Test
fun setTest()
{
val testname="test"
val testObject=Mockito.mock(Configuration::class.java)
doReturn("configTest").`when`(testObject).getConfig(Mockito.anyString())
setName(testname)
}
I am not getting any error but the method getConfig is not mocked. The actual implementation is executed. I tried using Powermockito also. Please help me with this
the problem is probably with singleton object, you can try this answer: https://stackoverflow.com/a/37978020/3703819

Mock a scheduleWithFixedDelay method using EasyMock

How can I mock the start() function in the following code using easyMock?
class A {
public runOnce(Integer a) {
// do something
}
public void start() {
executor.scheduleWithFixedDelay(() -> runOnce(12), 0, 1000, TimeUnit.MILLISECONDS);
}
}
I tried in the following way which is not working:
ScheduledExecutorService executorService = createMock(ScheduledExecutorService.class);
executorService.scheduleWithFixedDelay(anyObject(), eq(0), eq(1000), eq(TimeUnit.MILLISECONDS));
expectLastCall().andReturn(null);
A a = createMockBuilder(A.class).addMockedMethod(A.class.getDeclaredMethod("runOnce", Integer.class)).createMock();
a.runOnce(12);
expectLastCall();
replay(executorService);
a.start();
verify(executorService);
Can someone suggest how can I fix it?
I see two problems here. First, you are not injecting the mocked executorService into your A instance. I will assume you can use a constructor to do that.
A a = createMockBuilder(A.class)
.addMockedMethod(A.class.getDeclaredMethod("runOnce", Integer.class))
.withConstructor(executorService)
.createMock();
Then, matchers need to take the correct types in parameter. So here scheduleWithFixedDelay expects long. So the expect should be
expect(executorService.scheduleWithFixedDelay(anyObject(), eq(0L), eq(1000L), eq(TimeUnit.MILLISECONDS)))
.andReturn(null);
Doing this makes everything run smoothly.

doNothing method does not work with void static method

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

Should I add features in a class just to make it testable?

I am still trying to get the hang of unit testing, I have a simple question. Today I wanted to write a test for a very simple function. This function was doing just this:
void OnSomething()
{
increment++;
if (increment == 20)
SaveIt();
}
I said, this function could be testable. I could write a test that calls it 20 times and then verifies that SaveIt has been called.
Then my doubt arose. How can I test that SaveIt has been called? My first answer was to add a boolean, but then I thought: is it correct to add class features just to make it testable?
Please advise. Thank you.
I would suggest having SaveIt return a success or failure result, this just makes it easier to test overall. You could do something as simple as having it return a bool, or you could create a generic result class that contains the ability to set messages as well, if you ever need to report whether it passed or failed.
A simple example example
public class Result
{
public bool IsSuccess;
public List<string> Messages;
}
In the unit test you're trying to test only the OnSomething behavior though -- what happens inside "SaveIt" should not be tested. So ideally you'd want SaveIt() to occur in another class so you can mock its response.
I use Moq for this purpose. Moq is free, you can get it here: http://code.google.com/p/moq/
my method would then become
Result OnSomething()
{
Result result=null;
increment++;
if(increment == 20)
{
result = saver.SaveIt();
}
return result;
}
Your class constructor would take an object that implements ISaver interface (defining SaveIt() method) (ideally injected by a DI framework but you could generate it manually if you had to).
Now in your unit test you would create a mock version of ISaver and tell it what to return when it gets called:
Mock<ISaver> mock = new Mock<ISaver>();
mock.Setup(x=> x.SaveIt()).Returns(new Result{IsSuccess=true});
You'd instantiate your class passing mock.Object in the constructor ISaver parameter.
ex.
MyClass myClass = new MyClass(mock.Object);
//(assuming it didn't have other parameters)
Then, you could Assert whether result is null or not -- if it never got called, it would be null because the setup you did above would never trigger.
(in nunit)
Result result = myClass.OnSomething();
Assert.IsNotNull(result);
If you really didn't want OnSomething() to return a result, or it couldn't because it's an event, then I would have OnSomething() call a method to do the work for you:
void OnSomething()
{
Result result = DoTheWork();
}
Result DoTheWork()
{
Result result=null;
increment++;
if(increment == 20)
{
result = saver.SaveIt();
}
return result;
}
And then run your unit test on DoTheWork() instead of OnSomething().
Definitely not! Production code should not depend on tests at all, but the tests should verify the correct behaviour of the actual code. This can be achieved by several methods, such as IOC, and using mocks. You can take a look at some existing frameworks which simplify your life a lot:
http://code.google.com/p/mockito/
http://code.google.com/p/jmockit/
http://www.easymock.org/

How to use Rhino Mock to mock a local function calling?

Here is my situation:
I want to test on the "HasSomething()" function, which is in the following class:
public class Something
{
private object _thing;
public virtual bool HasSomething()
{
if (HasSomething(_thing))
return true;
return false;
}
public virtual bool HasSomething(object thing)
{
....some algo here to check on the object...
return true;
}
}
So, i write my test to be like this:
public void HasSomethingTest1()
{
MockRepository mocks = new MockRepository();
Something target = mocks.DynamicMock(typeof(Something)) as Something;
Expect.Call(target.HasSomething(new Object())).IgnoreArguments().Return(true);
bool expected = true;
bool actual;
actual = target.HasSomething();
Assert.AreEqual(expected, actual);
}
Is my test written correctly?
Please help me as i can't even get the result as expected. the "HasSomething(object)" just can't be mock in that way. it did not return me 'true' as being set in expectation.
Thanks.
In response to OP's 'answer': Your main problem is that RhinoMocks does not mock members of classes - instead it creates mock classes and we can then set expectations and canned responses for its members (i.e. Properties and Functions). If you attempt to test a member function of a mock/stub class, you run the risk of testing the mocking framework rather than your implementation.
For the particular scenario of the logical path being dependent on the return value of a local (usually private) function, you really need an external dependency (another object) which would affect the return value that you require from that local function. For your code snippet above, I would write the test as follows:
[Test]
public void TestHasSomething()
{
// here I am assuming that _thing is being injected in via the constructor
// you could also do it via a property setter or a function
var sut = new Something(new object());
Assert.IsTrue(sut.HasSomething);
}
i.e. no mocking required.
This is one point of misunderstanding that I often had in the past with regards to mocking; we mock the behaviour of a dependency of the system under test (SUT). Something like: the SUT calls several methods of the dependency and the mocking process provides canned responses (rather than going to the database, etc) to guide the way the logic flows.
A simple example would be as follows (note that I have used RhinoMocks AAA syntax for this test. As an aside, I notice that the syntax that you are using in your code sample is using the Record-Replay paradigm, except that it isn't using Record and Replay! That would probably cause problems as well):
public class SUT
{
Dependency _depend
public SUT (Dependency depend)
{
_depend = depend;
}
...
public int MethodUnderTest()
{
if (_depend.IsReady)
return 1;
else
return -1;
}
}
...
[Test]
public void TestSUT_MethodUnderTest()
{
var dependency = MockRepository.GenerateMock<Dependency>();
dependency.Stub(d => d.IsReady).Return(true);
var sut = new SUT(dependency);
Assert.AreEqual(1, sut.MethodUnderTest());
}
And so the problem that you have is that you are attempting to test the behaviour of a mocked object. Which means that you aren't actually testing your class at all!
In a case like this, your test double should be a derived version of class Something. Then you override the method HasSomething(object) and ensure that HasSomething() calls your one.
If I understand correctly, you are actually interested in testing the method HasDynamicFlow (not depicted in your example above) without concerning yourself with the algorithm for HasSomething.
Preet is right in that you could simply subclass Something and override the behavior of HasSomething to short-circuit the algorithm, but that would require creating some additional test-dummy code which Rhino is efficient at eliminating.
Consider using a Partial Mock Stub instead of a Dynamic Mock. A stub is less strict and is ideal for working with Properties. Methods however require some extra effort.
[Test]
public void CanStubMethod()
{
Foo foo = MockRepository.GenerateStub<Foo>();
foo.Expect(f => f.HasDynamicFlow()).CallOriginalMethod(OriginalCallOptions.NoExpectation);
foo.Expect(f => f.HasSomething()).CallOriginalMethod(OriginalCallOptions.NoExpectation);
foo.Expect(f => f.HasSomething(null)).IgnoreArguments().Return(true);
Assert.IsTrue(foo.HasDynamicFlow());
}
EDIT: added code example and switched Partial Mock to Stub