Java - Unit testing a void method using Matchers - unit-testing

I am trying to test a void method such as following:
#Override
public void onApplicationEvent(ApplicationEvent myEvent) {
if (myEvent instanceof ApplicationEnvironmentPreparedEvent) {
ConfigurableEnvironment myEnv= ((ApplicationEnvironmentPreparedEvent) myEvent).getEnvironment();
setSystemVariables(myEnv);
}
}
I am using Matchers and here is the unit test (which obviously is not testing anything)
#Test
public void testOnApplicationEvent() {
loggingListener.onApplicationEvent(any(ApplicationEnvironmentPreparedEvent.class));
}
Two issues:
1. The error I get from the build is "Invalid use of Matchers" and test doesn't pass in my Jenkins build (but passes in idea IDE)
2. How to test these methods to keep the test coverage percentage up to a desired level

1 - This issue because any is used incorrectly. Refer the Mockito guide for details. Below my example does not use any and the problem will be gone.
2 - To cover 2 branches of if I would recommend below test cases.
#Test
public void onApplicationEventShouldSetEnvironmentWhenApplicationEnvironmentPreparedEvent() {
ConfigurableEnvironment actualEnvironment = null;
// Given a listener with overridden setSystemVariables() to store passed env.
LoggingListener loggingListener = new LoggingListener() {
#Override
void setSystemVariables(ConfigurableEnvironment var){
actualEnvironment = var;
}
};
// Given some dummy environment which is delivered by an event.
ConfigurableEnvironment expectedEnvironment = new ConfigurableEnvironment();
// Given a mocked event with above dummy environment.
ApplicationEvent mockedEvent = Mockito(ApplicationEnvironmentPreparedEvent.class);
Mockito.when(mockedEvent.getEnvironment()).returns(expectedEnvironment);
// When call a method under test
loggingListener.onApplicationEvent(mockedEvent);
// Then make sure the given environment was passed and set correctly
assertSame(expectedEnvironment, actualEnvironment);
}
#Test
public void onApplicationEventShouldSkipNotApplicationEnvironmentPreparedEvent() {
// Given a listener with overridden setSystemVariables() to fail the test if called.
LoggingListener loggingListener = new LoggingListener() {
#Override
void setSystemVariables(ConfigurableEnvironment var){
fail("This method should not be called");
}
};
// Given a mocked other (not ApplicationEnvironmentPreparedEvent) event.
ApplicationEvent mockedEvent = Mockito(UnknownEvent.class);
// When call a method under test
loggingListener.onApplicationEvent(mockedEvent);
// Then make sure an environment was not asked at all.
Mockito.verify(mockedEvent.getEnvironment(), never);
}
Note, this is not compilable code, because I don't know your full production code, so treat this as an idea to apply it on your real code with corresponding modifications.

Related

Is possible to finish unit testing when a method is called?

Here is my test method where It should be success if showLoading() and loadDataSuccess(response) was called:
#RunWith(PowerMockRunner.class)
public class PresenterTest {
#Mock
private ProfileContract.View view;
#Mock
private ProfileContract.Handler handler;
#Test
public void onLoadDataClicked() {
presenter.loadData();
verify(mView, times(1)).showLoading();
verify(mHandler, times(1)).loadDataSuccess();
}
}
UPDATE 1
Here is my presenter:
class ProfilePresenter(private val mView: ProfileContract.View) : ProfileContract.Handler {
override fun loadData() {
mView.showLoading()
mUserService.user()
.compose(RxUtil.mapper())
.subscribe({ response ->
loadDataSuccess()
}, { error ->
//stuff
})
}
}
Thanks!
If you use return statment, your test finish with success status.
I think there is a basic problem with your test setup:
You do not use verify to check if one function calles another function within the same class. Verify is used to verify that the tested class calls function on other (mocked) classes. If I am not mistaken, your setup should actually give you an error message saying that you can not use verify on instantiated classes.
What you should do -if you want to check if onCompleteClicked() produces the correct results- is to check if the data that gets changed inside the onStuffComplete() function is set correctly. You can use an assert for that.
As an example, lets say onStuffCompleted() sets completeCounter to 1
#Test
public void onCompleteClicked() {
presenter.onStuffCompleteClicked();
assertEquals(completCounter , 1);
}
And to answer your original question: verify (and assert) will pass if the requirements were met (and by this the whole test will pass) and fail if not. You do not need to add any additional stuff (but once again: verify will only work with mocked classes).

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

In a unit test, do you verify and assert?

I am using Moq in my unit test project. Most unit test examples I've seen online end with someMock.VerifyAll(); I wonder if it is OK to assert after VerifyAll(). So for example,
//Arrange
var student = new Student{Id = 0, Name="John Doe", IsRegistered = false};
var studentRepository = new Mock<IStudentRepository>();
var studentService= new StudentService(studentRepository.Object);
//Act
studentService.Register(student); //<-- student.IsRegistered = true now.
//Verify and assert
studentRepository.VerifyAll();
Assert.IsTrue(student.IsRegistered);
Any thought? Thank you.
No you should not use both together in most cases(there are always exceptions). The reason for that is you should be testing only one thing in your test for maintainability, readability and few other reasons. So it should be either Verify(VerifyAll) or Assert in your test and you name your tests accordingly.
Look at Roy Osherove's article about it:
http://osherove.com/blog/2005/4/3/a-unit-test-should-test-only-one-thing.html
VerifyAll is used to make sure certain methods are called and how many times. You use mocks for that.
Assert is used for verifying the result returned from the method you are testing. You use Stubs for that.
Martin fowler has a great article explaining the difference between mocks and stubs. If you understand it you will know the difference better.
http://martinfowler.com/articles/mocksArentStubs.html
UPDATE: example of mock vs stub using Moq as requested in the comment below. I have used Verify but you can use VerifyAll as well.
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Moq;
...
[TestClass]
public class UnitTest1
{
/// <summary>
/// Test using Mock to Verify that GetNameWithPrefix method calls
/// Repository GetName method once when Id is greater than Zero
/// </summary>
[TestMethod]
public void GetNameWithPrefix_IdIsTwelve_GetNameCalledOnce()
{
// Arrange
var mockEntityRepository = new Mock<IEntityRepository>();
mockEntityRepository.Setup(m => m.GetName(It.IsAny<int>()));
var entity = new EntityClass(mockEntityRepository.Object);
// Act
var name = entity.GetNameWithPrefix(12);
// Assert
mockEntityRepository.Verify(
m => m.GetName(It.IsAny<int>()), Times.Once);
}
/// <summary>
/// Test using Mock to Verify that GetNameWithPrefix method
/// doesn't calls Repository GetName method when Id is Zero
/// </summary>
[TestMethod]
public void GetNameWithPrefix_IdIsZero_GetNameNeverCalled()
{
// Arrange
var mockEntityRepository = new Mock<IEntityRepository>();
mockEntityRepository.Setup(m => m.GetName(It.IsAny<int>()));
var entity = new EntityClass(mockEntityRepository.Object);
// Act
var name = entity.GetNameWithPrefix(0);
// Assert
mockEntityRepository.Verify(
m => m.GetName(It.IsAny<int>()), Times.Never);
}
/// <summary>
/// Test using Stub to Verify that GetNameWithPrefix method
/// returns Name with a Prefix
/// </summary>
[TestMethod]
public void GetNameWithPrefix_IdIsTwelve_ReturnsNameWithPrefix()
{
// Arrange
var stubEntityRepository = new Mock<IEntityRepository>();
stubEntityRepository.Setup(m => m.GetName(It.IsAny<int>()))
.Returns("Stub");
const string EXPECTED_NAME_WITH_PREFIX = "Mr. Stub";
var entity = new EntityClass(stubEntityRepository.Object);
// Act
var name = entity.GetNameWithPrefix(12);
// Assert
Assert.AreEqual(EXPECTED_NAME_WITH_PREFIX, name);
}
}
public class EntityClass
{
private IEntityRepository _entityRepository;
public EntityClass(IEntityRepository entityRepository)
{
this._entityRepository = entityRepository;
}
public string Name { get; set; }
public string GetNameWithPrefix(int id)
{
string name = string.Empty;
if (id > 0)
{
name = this._entityRepository.GetName(id);
}
return "Mr. " + name;
}
}
public interface IEntityRepository
{
string GetName(int id);
}
public class EntityRepository:IEntityRepository
{
public string GetName(int id)
{
// Code to connect to DB and get name based on Id
return "NameFromDb";
}
}
Yes you should call the assert.
VerifyAll() will assert that all SetUp() calls were actually called.
VerifyAll() will not confirm that your student object is registered. Because there are no SetUp() calls in your test case, I think VerifyAll() isn't verifying anything.
I would absolutely expect to see Verify and Assert used side-by-side within a unit test. Asserts are used to validate that properties of your system under test have been set correctly, whereas Verify is used to ensure that any dependencies that your system under test takes in have been called correctly. When using Moq I tend to err on the side of explicitly verifying a setup rather than using the VerifyAll catch-all. That way you can make the intent of the test much clearer.
I'm assuming in the code above that your call to the student repository returns a boolean to state that the student is registered? And you then set that value on the student object? In that case, there is a valuable setup that needs to be added, in which you are effectively saying that when the student repository method is called, it will return true. Then you Assert that student.IsRegistered is true to ensure that you have set the property correctly from the repository return value and you Verify that the repository method is called with the inputs that you are expecting.
There's nothing intrinsically wrong with both asserting and verifying in a mocking test, though assertions that depend on the actual methods being called are likely to fail, because the mock methods do not have the same effects as the real methods.
In your example it is probably fine, as only the repository is mocked, and the change of the student state is presumably done in the service.
Whether both verify and assert should be done in the same test is to a degree a matter of taste. Really the verify is checking that the proper calls to the repository are made, and the assert is checking that the proper change to the entity is made. As these are separate concerns, I'd put them in separate tests, but that may just be me.

Binding IDatabaseInitializer<> in my test to test my data context initialzer (EntityFramework 4.1 aka EF4 Code First)

I'm trying inject my database initializer so that I can use test data initializer in my unit test and the real one in production.
Here is my ninject module.
class IocBindings : NinjectModule
{
public override void Load()
{
Bind<DbContext>()
.To<ActualEntityFrameworkDataContext>();
Bind(typeof(IDatabaseInitializer<>))
.To(typeof(TestDataContextInitializer));
}
}
As you can see there is only one binding is defined; however when I run the test it fails do to the following exception:
Ninject.ActivationException : Error activating IDatabaseInitializer{TContext} More than one matching bindings are available.
I have a base testfixture in which I instantiate the kernel ans pass it into common service locator:
[TestFixture]
public class TestContext
{
private IKernel NinjectKernel { get; set; }
[SetUp]
public void setup()
{
NinjectKernel = new StandardKernel(new INinjectModule[] { new IocBindings() } );
ServiceLocator.SetLocatorProvider(() => new NinjectServiceLocator(NinjectKernel));
}
[TearDown]
public void TearDownAttribute()
{
NinjectKernel.Dispose();
}
}
I'm new to ninject so I'm not sure if I have set it up correctly.
any help in how to resolve this issue is very welcomed.
Cheers
I'm not sure what is the problem with my source code, but if I use the following line of code, I get no exception. Obviously, this is the only workaround!
Bind<DbContext>()
.To<ActualEntityFrameworkDataContext>()
.OnActivation(dbContext => (new TestDataContextInitializer()).InitializeDatabase(dbContext as ActualEntityFrameworkDataContext));

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