How to Write Tests in AEM

Use Case: Writing tests for AEM application.

Current Issue: As your project and code base grows, it is really important to make sure that test coverage for code is there to maintain consistency and sanity of your code. Writing test cases for AEM is little bit different than writing conventional Java test cases, This makes it difficult for beginner to write test cases for AEM application.

Idea of this post to give different options available for writing unit test for AEM services.

Prerequisite:

• Familiar with Java Junit test framework http://junit.org
• Familiar with Java Mockito test framework http://site.mockito.org/
• Optional: PowerMockito test framework http://powermock.github.io/

Good to know:

• Sling test framework (Mock and IT) https://sling.apache.org/documentation/development.html
• AEM Mock http://wcm.io/testing/aem-mock/  and http://wcm.io/testing/aem-mock/apidocs/
• WCMUse classes Mocking http://aempodcast.com/2015/testing/unit-testing-wcmuse-classes-using-mockito/#.WEmiUMMrJKc

I would explain how you can have better test coverage for your application by giving different use cases,

Dependencies: It is recommended to have following dependencies in to your pom before start writing for tests for your application

	<dependency>
	<groupId>junit</groupId>
	<artifactId>junit</artifactId>
	<version>4.8.2</version>
	<scope>test</scope>
	</dependency>
	<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-simple</artifactId>
	<version>1.5.11</version>
	<scope>test</scope>
	</dependency>
	<dependency>
	<groupId>junit-addons</groupId>
	<artifactId>junit-addons</artifactId>
	<version>1.4</version>
	<scope>test</scope>
	</dependency>
	<!-- Custom WCM Mock for AEM6 -->
	<dependency>
	<groupId>io.wcm</groupId>
	<artifactId>io.wcm.testing.aem-mock</artifactId>
	<version>1.3.0</version>
	</dependency>
	<!-- Sling Mocks -->
	<dependency>
	<groupId>org.apache.sling</groupId>
	<artifactId>org.apache.sling.testing.resourceresolver-mock</artifactId>
	<version>1.1.4</version>
	</dependency>
	<dependency>
	<groupId>org.apache.sling</groupId>
	<artifactId>org.apache.sling.testing.osgi-mock</artifactId>
	<version>1.2.0</version>
	</dependency>
	<dependency>
	<groupId>org.apache.sling</groupId>
	<artifactId>org.apache.sling.testing.sling-mock</artifactId>
	<version>1.2.0</version>
	</dependency>
	<dependency>
	<groupId>org.apache.sling</groupId>
	<artifactId>org.apache.sling.testing.jcr-mock</artifactId>
	<version>1.1.4</version>
	</dependency>
	<dependency>
	<groupId>org.mockito</groupId>
	<artifactId>mockito-core</artifactId>
	<version>1.10.19</version>
	<scope>test</scope>
	</dependency>
	<dependency>
	<groupId>org.mockito</groupId>
	<artifactId>mockito-all</artifactId>
	<version>1.10.19</version>
	<scope>test</scope>
	</dependency>
	<dependency>
	<groupId>org.powermock</groupId>
	<artifactId>powermock-module-junit4</artifactId>
	<version>1.6.2</version>
	<scope>test</scope>
	</dependency>
	<dependency>
	<groupId>org.powermock</groupId>
	<artifactId>powermock-api-mockito</artifactId>
	<version>1.6.2</version>
	<scope>test</scope>
	</dependency>
	<dependency>
	<groupId>com.adobe.aem</groupId>
	<artifactId>uber-jar</artifactId>
	<version>6.1.2</version>
	<classifier>apis</classifier>
	<scope>provided</scope>
	</dependency>

view raw aemtestpom.xml hosted with ❤ by GitHub

Case 1: Writing test cases for Generic Helper class.

This is simplest use case where your generic helper class (For example StringUtils, DateUtils) is not using any AEM libraries. For this you can simply use Junit to write your unit test. https://www.tutorialspoint.com/junit

Here is very simple example:

	package com.wemblog.foundation.utility;
	import static org.junit.Assert.assertEquals;
	import static org.junit.Assert.assertFalse;
	import static org.junit.Assert.assertTrue;
	import java.util.ArrayList;
	import java.util.List;
	import org.junit.Test;
	public class CommonStringUtilTest {
	@Test
	public void testIsEmpty() {
	assertTrue(CommonStringUtil.isEmpty(""));
	assertFalse(CommonStringUtil.isEmpty(" "));
	assertFalse(CommonStringUtil.isEmpty("test"));
	assertFalse(CommonStringUtil.isEmpty(" test "));
	assertTrue(CommonStringUtil.isEmpty(null));
	}
	@Test
	public void testIsEmptyWithTrim() {
	assertTrue(CommonStringUtil.isEmpty("", false));
	assertTrue(CommonStringUtil.isEmpty(" ", true));
	assertFalse(CommonStringUtil.isEmpty(" ", false));
	assertFalse(CommonStringUtil.isEmpty("test", true));
	assertFalse(CommonStringUtil.isEmpty(" test ", true));
	assertTrue(CommonStringUtil.isEmpty(null, true));
	assertTrue(CommonStringUtil.isEmpty(null, false));
	}
	@Test
	public void testConvertArrayToString() {
	String[] test = { "test1", "test2" };
	assertEquals(CommonStringUtil.convertArrayToString(new String[1]), "");
	assertEquals(CommonStringUtil.convertArrayToString(null), "");
	assertEquals(CommonStringUtil.convertArrayToString(test), "test1,test2");
	test[1] = "test3 test4";
	assertEquals(CommonStringUtil.convertArrayToString(test), "test1,test3 test4");
	ArrayList<String> test1 = new ArrayList<String>();
	test1.add("test1 test2");
	test1.add("test3");
	assertEquals(CommonStringUtil.convertArrayToString(test1.toArray(new String[test1.size()])),
	"test1 test2,test3");
	}
	@Test
	public void testConvertArrayListToString() {
	List<String> test = new ArrayList<String>();
	assertEquals(CommonStringUtil.convertArrayListToString(null), "");
	assertEquals(CommonStringUtil.convertArrayListToString(test), "");
	test.add("test1");
	test.add("test2");
	assertEquals(CommonStringUtil.convertArrayListToString(test), "test1,test2");
	test.add("test3 test4");
	assertEquals(CommonStringUtil.convertArrayListToString(test), "test1,test2,test3 test4");
	}
	}

view raw CommonStringUtilTest.java hosted with ❤ by GitHub

Case 2: Writing test cases for AEM Helper class

This is second use case where you want to test AEM helper methods. For this you can use combination of Junit and Mockito. Use Mockito to Mock AEM services and methods and Junit for assertion.

Here is simple example

	package com.wemblog.util;
	import static org.junit.Assert.assertEquals;
	import static org.junit.Assert.assertFalse;
	import static org.junit.Assert.assertNotNull;
	import static org.junit.Assert.assertNull;
	import static org.junit.Assert.assertTrue;
	import static org.mockito.Mockito.mock;
	import static org.mockito.Mockito.when;
	import javax.servlet.http.Cookie;
	import javax.servlet.jsp.PageContext;
	import org.apache.sling.api.SlingHttpServletRequest;
	import org.apache.sling.api.resource.NonExistingResource;
	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.Mock;
	import org.mockito.runners.MockitoJUnitRunner;
	import com.day.cq.commons.Externalizer;
	@RunWith(MockitoJUnitRunner.class)
	public class LiCommonRequestUtilsTest {
	@Mock
	SlingHttpServletRequest _httpServletRequest;
	@Mock
	ResourceResolver _resourceResolver;
	@Mock
	Resource _resource;
	@Mock
	Cookie _bCookie;
	@Mock
	Externalizer _externalizer;
	@Before
	public void setUp() {
	when(_httpServletRequest.getServerName()).thenReturn("www.test.com");
	when(_httpServletRequest.getRequestURI()).thenReturn("/something/andsomething");
	}
	/**
	* 1. When there is Host header 2. No Host Header 3. Host Header Null 4. Host Header Empty
	*
	*/
	@Test
	public void getServerNameTest() {
	assertNull(LiCommonRequestUtils.getServerName(null));
	assertEquals(LiCommonRequestUtils.getServerName(_httpServletRequest), "www.test.com");
	when(_httpServletRequest.getHeader("Host")).thenReturn("www.test2.com");
	assertEquals(LiCommonRequestUtils.getServerName(_httpServletRequest), "www.test2.com");
	when(_httpServletRequest.getHeader("Host")).thenReturn("");
	assertEquals(LiCommonRequestUtils.getServerName(_httpServletRequest), "www.test.com");
	when(_httpServletRequest.getHeader("Host")).thenReturn(null);
	assertEquals(LiCommonRequestUtils.getServerName(_httpServletRequest), "www.test.com");
	}
	/**
	* 1. Null test 2. With http header only 3. With http header and netscalar header 4. With https header 5. With https
	* and null netscalar header
	*/
	@Test
	public void isHttpOrHttpsRequestTest() {
	// For null input
	assertFalse(LiCommonRequestUtils.isHTTPRequest(null));
	assertFalse(LiCommonRequestUtils.isHTTPSRequest(null));
	.thenReturn(LiCommonRequestUtils.HTTPS_PROTOCOL);
	assertFalse(LiCommonRequestUtils.isHTTPRequest(_httpServletRequest));
	assertTrue(LiCommonRequestUtils.isHTTPSRequest(_httpServletRequest));
	when(_httpServletRequest.getProtocol()).thenReturn("HTTP/1.1");
	assertTrue(LiCommonRequestUtils.isHTTPRequest(_httpServletRequest));
	assertFalse(LiCommonRequestUtils.isHTTPSRequest(_httpServletRequest));
	// If it is https request
	when(_httpServletRequest.getProtocol()).thenReturn("HTTPS/1.1");
	assertFalse(LiCommonRequestUtils.isHTTPRequest(_httpServletRequest));
	assertTrue(LiCommonRequestUtils.isHTTPSRequest(_httpServletRequest));
	}
	@Test
	public void getCompleteResourcePathTest() {
	// Null check
	assertNull(LiCommonRequestUtils.getCompleteResourcePath(null));
	// Exact Path check
	when(_httpServletRequest.getRequestURI()).thenReturn("/content/test/test");
	when(_resource.getPath()).thenReturn("/content/test/test");
	when(_resourceResolver.resolve("/content/test/test")).thenReturn(_resource);
	when(_httpServletRequest.getResourceResolver()).thenReturn(_resourceResolver);
	assertEquals(LiCommonRequestUtils.getCompleteResourcePath(_httpServletRequest), "/content/test/test");
	// Vanity Path check
	when(_httpServletRequest.getRequestURI()).thenReturn("/vanity/test/test");
	when(_resourceResolver.resolve("/vanity/test/test")).thenReturn(_resource);
	assertEquals(LiCommonRequestUtils.getCompleteResourcePath(_httpServletRequest), "/content/test/test");
	// Non existance Resource check
	when(_resourceResolver.resolve("/vanity/test/test")).thenReturn(new NonExistingResource(_resourceResolver, null));
	assertNull(LiCommonRequestUtils.getCompleteResourcePath(_httpServletRequest));
	}
	/**
	* 1. True 2. True 3. False 4. False 5. False 6. False 7. False
	*/
	@Test
	public void isValidIPAddressTest() {
	// true for valid IPV4
	assertTrue(LiCommonRequestUtils.isValidIPAddress("199.101.162.221"));
	// true for valid IPV6
	assertTrue(LiCommonRequestUtils.isValidIPAddress("2620:109:c00d:100::c765:a381"));
	// false if IP is null
	assertFalse(LiCommonRequestUtils.isValidIPAddress(null));
	// false if ip is blank
	assertFalse(LiCommonRequestUtils.isValidIPAddress(""));
	// false if its a random string
	assertFalse(LiCommonRequestUtils.isValidIPAddress("1.3.1.1.1.1.1.1.1"));
	// false if its a random string
	assertFalse(LiCommonRequestUtils.isValidIPAddress("abc.f.ve.c"));
	// false if its a random string
	assertFalse(LiCommonRequestUtils.isValidIPAddress("test"));
	}
	/**
	* 1. True 2. True 3. False 4. False 5. False 6. False 7. False 8. False
	*/
	@Test
	public void isIPV6AddressTest() {
	// true for valid compressed IPV6
	assertTrue(LiCommonRequestUtils.isIPV6Address("2620:109:c00d:100::c765:a381"));
	// true for valid standard IPV6
	assertTrue(LiCommonRequestUtils.isIPV6Address("3ffe:1900:4545:3:200:f8ff:fe21:67cf"));
	// false if IP is null
	assertFalse(LiCommonRequestUtils.isIPV6Address(null));
	// false if ip is blank
	assertFalse(LiCommonRequestUtils.isIPV6Address(""));
	// false if its a random string
	assertFalse(LiCommonRequestUtils.isIPV6Address("1.3.1.1.1.1.1.1.1"));
	// false if its a random string
	assertFalse(LiCommonRequestUtils.isIPV6Address("abc.f.ve.c"));
	// false if its a random string
	assertFalse(LiCommonRequestUtils.isIPV6Address("test"));
	// true for valid IPV4
	assertFalse(LiCommonRequestUtils.isIPV6Address("199.101.162.221"));
	}
	}

view raw LiCommonRequestUtilsTest.java hosted with ❤ by GitHub

Case 3: Writing test cases for AEM services

Now it gets little bit tricky where you need to mock certain behavior of bundle and implicit object. That's why Sling has created Mock version of sling objects and wcm.io has created mock version of AEM objects. You can just use aem mock http://wcm.io/testing/aem-mock/ to achieve most of your use cases. (AEM mock extend Sling mock).

here are some of the common use cases you will come across while testing your service.

1) How can I mock content my service is running against ?

For this it is recommended to use contentLoader API http://wcm.io/testing/aem-mock/usage.html to either load existing json based resource (You can simply get it by creating resource in CRXDE and then using something like RESOURCEPATH.infinity.json to get json for that resource) or just create mock resource using ContentBuilder context.create().resource() or ResourceBuilder context.build().resource() http://wcm.io/testing/aem-mock/apidocs/

Note that if you are mocking Page object then you have to use aem mock using aemcontext.pageManager().create()

2) How Can I initialize properties in the bundle ?

You can use register and activate OSGI service with properties http://wcm.io/testing/aem-mock/usage.html#Registering_OSGi_service for that. Here is some example

	//Method 1, By using Inject Mock
	@RunWith(PowerMockRunner.class)
	@PrepareForTest(MyServiceImpl.class)
	public class MyServiceImplTest {
	@InjectMocks
	MyServiceImpl _myService;
	@Before
	public void setUp() throws Exception {
	_config = new HashMap<Object, Object>();
	_config.put("test1", "test1");
	_config.put("test2", "test3");
	}
	@Test
	public void someTest() {
	myService.activate(_config);
	assertEquals("test", something.yourMethod());
	}
	}
	//Method 2 using AEM context
	public class MyServiceImplTest {
	MyServiceImpl _myService;
	@Rule
	public final AemContext aemContext = new AemContext();
	@Before
	public void setUp() throws Exception {
	_config = new HashMap<Object, Object>();
	_config.put("test1", "test1");
	_config.put("test2", "test3");
	_myService = aemContext.registerInjectActivateService(new MyServiceImpl(), _config);
	}
	@Test
	public void someTest() {
	assertEquals("test", _myService.yourMethod());
	}
	}

view raw MyServiceImplTest.java hosted with ❤ by GitHub

3) How Can I inject other service for my service ?

You can either Mock service or use register service API for that http://wcm.io/testing/aem-mock/usage.html#Registering_OSGi_service

Note that when you inject a service to your service using Reference then you have to register this your injected service, otherwise your test will fail.

4) How Can I test sling model ?

You can use aemContext for that. http://wcm.io/testing/aem-mock/usage.html#Sling_Models


Case 4: Writing test cases for AEM servlets and filters

This is very similar to how you would do test cases for Service. For request and response you either have to mock request / response object using Mockito or Use Spy  or use sling request and response mock. Since a lot of methods in filter and servlet do not return any result, Make Mockito verify your friend.  Here is one example using simple mockito to test servlet

	package com.wemblog.test;
	import com.adobe.granite.xss.XSSAPI;
	import com.google.gson.JsonArray;
	import java.io.ByteArrayOutputStream;
	import java.io.IOException;
	import java.io.PrintWriter;
	import static org.junit.Assert.*;
	import static org.mockito.Mockito.any;
	import static org.mockito.Mockito.mock;
	import static org.mockito.Mockito.when;
	import static org.mockito.Mockito.doThrow;
	import static org.mockito.Mockito.doAnswer;
	import io.wcm.testing.mock.aem.junit.AemContext;
	import org.apache.sling.testing.mock.sling.ResourceResolverType;
	import com.google.gson.JsonObject;
	import com.google.gson.JsonParser;
	import org.apache.sling.api.SlingHttpServletRequest;
	import org.apache.sling.api.SlingHttpServletResponse;
	import org.junit.Before;
	import org.junit.Test;
	import org.junit.Rule;
	import org.junit.runner.RunWith;
	import org.mockito.InjectMocks;
	import org.mockito.Mock;
	import org.mockito.invocation.InvocationOnMock;
	import org.mockito.stubbing.Answer;
	import org.mockito.runners.MockitoJUnitRunner;
	@RunWith(MockitoJUnitRunner.class)
	public class AEMServletTest {
	private String answerFromDoGet = "";
	private int statusForDoGet = 0;
	private JsonParser parser = new JsonParser();
	@Rule
	public final AemContext _context = new AemContext(ResourceResolverType.RESOURCERESOLVER_MOCK);
	@Mock
	private AEMTreatmentService _aemTreatServe = mock(AEMTreatmentService.class);
	SlingHttpServletRequest _httpServletRequest = mock(SlingHttpServletRequest.class);
	SlingHttpServletResponse _httpServletResponse = mock(SlingHttpServletResponse.class);
	XSSAPI _xssapi = mock(XSSAPI.class);
	PrintWriter _respOut = mock(PrintWriter.class);
	@InjectMocks
	AEMTreatmentServlet _aemServlet;
	@Before
	public void setUp() {
	_context.registerService(AEMTreatmentService.class, _aemTreatServe);
	try {
	when(_httpServletResponse.getWriter()).thenReturn(_respOut);
	doAnswer(new Answer<Object>() {
	public Object answer(InvocationOnMock invocation) throws IOException {
	Object[] args = invocation.getArguments();
	answerFromDoGet = (String) args[0];
	return null;
	}
	}).when(_respOut).write(any(String.class));
	} catch (Exception e) {
	}
	}
	@Test
	public void testDoGet() {
	try {
	when(_httpServletRequest.getParameter(AEMTreatmentService.TREATMENT_PARAM)).thenReturn("foo");
	_aemServlet.doGet(_httpServletRequest, _httpServletResponse);
	JsonObject result = parser.parse(answerFromDoGet).getAsJsonObject();
	assertEquals("correctly set status", SlingHttpServletResponse.SC_OK,
	result.get(AEMTreatmentService.STATUS_KEY).getAsInt());
	} catch (Exception e) {
	assertTrue("error running testDoGet: " + e.getMessage(), false);
	}
	}
	/**
	* Test that the servlet returns the correct error state when the user fails
	* to provide a testKey parameter.
	*/
	@Test
	public void testDoGetNoTestKey() {
	try {
	when(_httpServletRequest.getParameter(AEMTreatmentService.TEST_PARAM)).thenReturn("");
	_aemServlet.doGet(_httpServletRequest, _httpServletResponse);
	JsonObject result = parser.parse(answerFromDoGet).getAsJsonObject();
	assertEquals("correctly set status", SlingHttpServletResponse.SC_BAD_REQUEST,
	result.get(AEMTreatmentService.STATUS_KEY).getAsInt());
	} catch (Exception e) {
	assertTrue("error running testDoGet: " + e.getMessage(), false);
	}
	}
	@Test
	public void testDoGetQAMode() {
	try {
	when(_httpServletRequest.getParameter(AEMTreatmentService.QA_MODE_PARAM)).thenReturn("true");
	_aemServlet.doGet(_httpServletRequest, _httpServletResponse);
	JsonObject result = parser.parse(answerFromDoGet).getAsJsonObject();
	assertEquals("correctly set QA override", true, result.get(AEMTreatmentService.QA_MODE_KEY).getAsBoolean());
	} catch (Exception e) {
	assertTrue("error running testDoGet: " + e.getMessage(), false);
	}
	}
	}

view raw AEMServletTest.java hosted with ❤ by GitHub

 How can I measure my test coverage ?

 You can use jococo test coverage plugin along with your build system to measure this coverage. You can have following plugin in to your parent pom

	<plugin>
	<groupId>org.jacoco</groupId>
	<artifactId>jacoco-maven-plugin</artifactId>
	<version>0.7.2.201409121644</version>
	<executions>
	<!-- Prepares the property pointing to the JaCoCo runtime agent
	which is passed as VM argument when Maven the Surefire plugin is executed. -->
	<execution>
	<id>pre-unit-test</id>
	<goals>
	<goal>prepare-agent</goal>
	</goals>
	<configuration>
	<!-- Sets the name of the property containing the settings for JaCoCo runtime agent. -->
	<propertyName>surefireArgLine</propertyName>
	</configuration>
	</execution>
	<!-- Ensures that the code coverage report for unit tests is created
	after unit tests have been run. -->
	<execution>
	<id>post-unit-test</id>
	<phase>test</phase>
	<goals>
	<goal>report</goal>
	</goals>
	<configuration>
	<!-- Sets the output directory for the code coverage report. -->
	<outputDirectory>${project.reporting.outputDirectory}/jacoco-ut</outputDirectory>
	</configuration>
	</execution>
	<execution>
	<id>unit-test-check</id>
	<goals>
	<goal>check</goal>
	</goals>
	<configuration>
	<rules>
	<rule>
	<element>BUNDLE</element>
	<limits>
	<limit>
	<counter>LINE</counter>
	<value>COVEREDRATIO</value>
	<minimum>0.90</minimum>
	</limit>
	<limit>
	<counter>BRANCH</counter>
	<value>COVEREDRATIO</value>
	<minimum>0.90</minimum>
	</limit>
	<limit>
	<counter>METHOD</counter>
	<value>COVEREDRATIO</value>
	<minimum>0.90</minimum>
	</limit>
	<limit>
	<counter>CLASS</counter>
	<value>COVEREDRATIO</value>
	<minimum>0.90</minimum>
	</limit>
	</limits>
	</rule>
	</rules>
	</configuration>
	</execution>
	</executions>
	</plugin>

view raw jacocoaempom.xml hosted with ❤ by GitHub

How Can I write Integration test in AEM ?

Very good example here https://github.com/sneakybeaky/AEM-Integration-Test-Example

It is based of sling test base https://sling.apache.org/documentation/development/sling-testing-tools.html

I know this information is not enough to have you set up for writing tests in AEM. Feel free to let me know if you have more question and I will add more stuff here.