AEM Helper

  Below are the common cause for NullPointerException and Null value in Junit test for Sling model: Problem with the adaptables Let say your sling model is adaptables to sling Resource and in your test class you are trying to get the instance of your respective Object by adapting request of aemContext. In this case you will end up with NullPointerException.  For example: Sling Model : @Model ( adaptables = { Resource .class}, adapters = { SolutionHeroComponent .class}, resourceType = { SolutionHeroComponentImpl .RESOURCE_TYPE}, defaultInjectionStrategy = DefaultInjectionStrategy .OPTIONAL ) @Exporter ( name = "jackson" , selector = "solutionhero" , extensions = "json" ) public class SolutionHeroComponentImpl implements SolutionHeroComponent { protected static final String RESOURCE_TYPE = "myproject/components/solutionhero" ; @Inject @Named (SOLUTION_HERO_TITLE) ...

 I was implementing Unit testing for a already running AEM project. After adding all the dependencies and after creation of basic structure for Sling model test class my test gets executed as expected. @ ExtendWith ({ AemContextExtension . class , MockitoExtension . class }) class DummyComponentImplTest { @ BeforeEach void setUp () { } @ Test public void testGetHeading () { } } But soon as I add below line at line #25 in the above running test case private final AemContext aemContext = new AemContext (); and try to run the test in terminal getting below error in the terminal's maven console. Running com . myproject . aem . models . impl . DummyComponentImplTest [ERROR] Tests run : 1 , Failures : 0 , Errors : 1 , Skipped : 0 , Time elapsed : 2.258 s <<< FAILURE! - in com . myproject . aem . models . impl . DummyComponentImplTest [ERROR] testGetHeading Time elapsed : 0.007 s <<< ERROR! java . lang . NoSuchFieldError...