Unit testing or Junit for Sling models using Mockito in AEM

Unit testing or Junit for Sling models using Mockito in AEM

• First generate AEM sample project with the help of below archetype which will download the sample AEM project compatible in AEM 6.5

mvn -B archetype:generate -D archetypeGroupId=com.adobe.granite.archetypes -D archetypeArtifactId=aem-project-archetype -D archetypeVersion=23 -D aemVersion=cloud -D appTitle="Training" -D appId="training" -D groupId="com.training"-D frontendModule=general -D includeExamples=n

           This will generate a project with below structure

Now add the dependency for Mockito

• Add below entry in main pom.xml

           
    

• Add below entry to core/pom.xml .       
  
  

     

• Create new Sling model class with name 'HelloIndiaModel' which will have Sling Objects such as Resource and ResourceResolver, init method and public method getMessage which will return a message based on few conditions.

import com.day.cq.wcm.api.Page;

import com.day.cq.wcm.api.PageManager;

import org.apache.sling.api.resource.Resource;

import org.apache.sling.api.resource.ResourceResolver;

import org.apache.sling.models.annotations.Model;

import org.apache.sling.models.annotations.injectorspecific.SlingObject;

import javax.annotation.PostConstruct;

import java.util.Optional;

@Model(adaptables = Resource.class)

public class HelloIndiaModel {

    @SlingObject

    private Resource currentResource;

    @SlingObject

    private ResourceResolver resourceResolver;

    private String message;

    @PostConstruct

    protected void init() {

        PageManager pageManager = resourceResolver.adaptTo(PageManager.class);

        String currentPagePath = Optional.ofNullable(pageManager)

                .map(pm -> pm.getContainingPage(currentResource))

                .map(Page::getPath).orElse("");

        message = "Hello " + getRegion(currentPagePath);

    }

    private String getRegion(String currentPagePath){

        if(currentPagePath.contains("geometrixx")){

            return "Geometrixx";

        }else if(currentPagePath.contains("India")){

            return "Indians";

        }

        else {

            return "World";

        }

    }

    public String getMessage() {

        return message;

    }

}

• Now go to test folder , create test class for HelloIndiaModel, this class should have an annotation @RunWith(MockitoJUnitRunner.class) which keeps tests clean and improves debugging experience.

• Try to understand the logic of init method from HelloIndiaModel, first line is using resourceresolver to adapt to PageManager. Since both of these objects are AEM/Sling Objects so we need to mock these Objects in our HelloIndiaModelTest class

• Line 3 is trying to get the Page from page manager object, Page Object is also belongs to AEM hence we need to mock this object as well

    @Mock

    private Resource currentResource;

    @Mock

    private ResourceResolver resourceResolver;

    @Mock

    private Page currentPage;

    @Mock

    private PageManager pageManager;

• We have used the @Mock since we need these objects to support testing of class to be tested.
• Now we need to call the Object of the class which we wish to write test, which can be done by . using the @InjectMocks

    @InjectMocks

    private HelloIndiaModel helloIndiaModel; 

• Now we need to handle the logic which is written using sling objects in sling model. For example :- what should mockito do when it reaches to the line resourceResolver.adaptTo(PageManager.class); We can specify this with the help of @Before method. 

Methods annotated with the @Before annotation are executed before each test. This is useful when we want to execute some common code before running a test.

@Before
public void setUp() {

    when(resourceResolver.adaptTo(PageManager.class)).thenReturn(pageManager);
    when(pageManager.getContainingPage(currentResource)).thenReturn(currentPage);
    when(currentPage.getPath()).thenReturn("/content/geometrixx");

    helloIndiaModel.init();

}

• Write first test for the method getMessage

   @Test

   public void shouldMatch(){

         assertNotNull(helloIndiaModel.getMessage());

         assertEquals("Hello Geometrixx",helloIndiaModel.getMessage());

   }

Please find below the complete Test class

import com.day.cq.wcm.api.Page;
import com.day.cq.wcm.api.PageManager;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.resource.ResourceResolver;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.MockitoJUnitRunner;

import static junit.framework.Assert.assertNotNull;
import static junitx.framework.Assert.assertEquals;
import static junitx.framework.Assert.assertNotEquals;
import static org.mockito.Mockito.when;

@RunWith(MockitoJUnitRunner.class)
public class HelloIndiaModelTest {

    @Mock
    private Resource currentResource;

    @Mock
    private ResourceResolver resourceResolver;

    @Mock
    private Page currentPage;

    @Mock
    private PageManager pageManager;

    @InjectMocks
    private HelloIndiaModel helloIndiaModel;

    //initialize
    @Before
    public void setUp() {

        when(resourceResolver.adaptTo(PageManager.class)).thenReturn(pageManager);
        when(pageManager.getContainingPage(currentResource)).thenReturn(currentPage);
        when(currentPage.getPath()).thenReturn("/content/geometrixx");

        helloIndiaModel.init();

    }

    @Test
    public void shouldNotMatch(){
        assertNotNull(helloIndiaModel.getMessage());
        assertNotEquals("Hiiiii",helloIndiaModel.getMessage());
    }

    @Test
    public void shouldMatch(){
        assertNotNull(helloIndiaModel.getMessage());
        assertEquals("Hello Geometrixx",helloIndiaModel.getMessage());
    }