How can i make use of mockito to resolve a null pointer exception in my test junit method which are concerned with license of a plugin?

[Neeraj Bodhe]

I mock ThirdPartyPluginLicenseStorageManager and PluginLicense.class using mockito in a junit test.

But while calling the internal methods of them it throws null pointer exception.

How can i overcome them as i dont see a way of setting the values in the mock confluence license objects

Few lines in my macro stub

@Mock
private ThirdPartyPluginLicenseStorageManager licenseManager;

@Before
public void setUp() throws Exception {
   super.setUp();
   exampleMacro = new Macro(licenseManager);
   PluginLicense pluginLicense = Mockito.mock(PluginLicense.class);
}

@Test
public void test() throws Exception {

   when(pluginLicense.getError().isDefined()).thenReturn(Boolean.FALSE); // Null pointer Exception
   when(licenseManager.getLicense().isDefined()).thenReturn(Boolean.TRUE); // Null pointer Exception

}

Few lines in my macro code which are throwing null pointer exception

private final ThirdPartyPluginLicenseStorageManager licenseManager;

public Macro(ThirdPartyPluginLicenseStorageManager licenseManager){
        this.licenseManager = licenseManager;
}

PluginLicense pluginLicense = licenseManager.getLicense().get();
if(licenseManager.getLicense().isDefined()) {
	if(pluginLicense.getError().isDefined()) {
	
	}
}

[Panos]

In the mock code you showed, in the setup method you mock a pluginLicense object. In test method you use another object.

Move this

PluginLicense pluginLicense = Mockito.mock(PluginLicense.class);

in the global declaration just below your licenseManager and delete any other pluginLicense that you have declared somewhere else.

[Neeraj Bodhe]

Did that @Mock private PluginLicense pluginLicense; Same null pointer exception error.

[Panos]

PluginLicense pluginLicense = licenseManager.getLicense().get(); is this mocked?

[Neeraj Bodhe]

i am new to mockito Can you just give me an example of how to mock this statement as there is no setter method like licenseManager.setLicense() to it. How to mock this?

[Panos]

Generally the idea is like... when(mockedObject.method()).thenReturn(something) right? In your occassion, licenseManager.getLicense() returns an Option<PluginLicense> so the mock should be:

when(licenseManager.getLicense()).thenReturn(Option.option(pluginLicense));

This is untested though 

In mockito you dont do setters. Lets say you have an interface method that with parameter string X returns object T and another method that with object T, returns string X.

the you would

Mockito.when(myInterface.myMethod(anyString())).thenReturn(T); //Notice the anyString() in this case i dont care what the param is.

the second case would be

Mockito.when(myInterface.myOtherMethod(T)).thenReturn(X);

To mock correctly i suggest you a) read documentation ofc and b) have the documentation of the method signatures on hand.

[Geoff Williams]

This was helpful but I had to use PowerMock instead of Mockito because the `isDefined` method is final :(

I ended up making my own Mock version of PluginLicenseManager with a method like this:

@Override
public Option<PluginLicense> getLicense() {
Option<PluginLicense> option = PowerMockito.mock(Option.class);

PluginLicense pluginLicense = PowerMockito.mock(PluginLicense.class);
Option<PluginLicense> optionError = PowerMockito.mock(Option.class);
PowerMockito.doReturn(error).when(optionError).isDefined();
PowerMockito.doReturn(optionError).when(pluginLicense).getError();

PowerMockito.doReturn(licensed).when(option).isDefined();
PowerMockito.doReturn(pluginLicense).when(option).get();

return option;
}

error and license being simple booleans defined as part of the class.

Also had to make sure my test runner was annotated:

@RunWith(PowerMockRunner.class)
@PrepareForTest(Option.class)

Still get some strange warnings from the depths of PowerMock but it works...

WARNING: Illegal reflective access by org.powermock.reflect.internal.WhiteboxImpl (file:/home/geoff/.m2/repository/org/powermock/powermock-reflect/2.0.2/powermock-reflect-2.0.2.jar) to method java.lang.Object.clone()
WARNING: Please consider reporting this to the maintainers of org.powermock.reflect.internal.WhiteboxImpl
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

 HTH