PluginPublic

adobe/aem-cloud-service

All AEM as a Cloud Service skills: component development, Workflow model design, development, triggering, launchers, debugging, and triaging, Dispatcher config authoring, advisory, incident response, performance tuning, and security hardening, Rapid Development Environment (RDE) deployment, log inspection, snapshots, and troubleshooting via `aio aem rde`, Jackrabbit Oak query/index tuning (property, Lucene index definitions), and extracting/inventorying JCR queries (XPath, SQL2, QueryBuilder) across a codebase.

Quality

85%

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Securityby

Low

Low-risk findings worth noting

Testing Patterns for AEM Components

Patterns for creating unit tests using wcm.io AEM Mocks with JUnit 5.

Critical Rules
Test Class Structure
Test Naming Convention
Required Test Scenarios
Creating Test Resources
Assertions
Code Coverage Goals
- Coverage Strategy
Common Mistakes to Avoid
Quick Checklist

Critical Rules

Rule 1: NEVER Mock Resource.adaptTo()

Resource.adaptTo() is a final method and cannot be mocked.

// WRONG - Will fail
Resource resource = mock(Resource.class);
when(resource.adaptTo(MyModel.class)).thenReturn(mockModel); // FAILS!

// CORRECT - Use AemContext
Resource resource = context.create().resource("/content/test", "title", "Test");
MyModel model = resource.adaptTo(MyModel.class);

Rule 2: Register All Sling Models

@BeforeEach
void setUp() {
    context.addModelsForClasses(ParentModel.class, ChildItemModel.class);
}

Rule 3: Use Real Resources, Not Mocks

// CORRECT
Resource parent = context.create().resource("/content/test", "title", "My Title");
context.create().resource("/content/test/items/item0", "itemTitle", "Item 1");
ParentModel model = parent.adaptTo(ParentModel.class);

// WRONG - Too complex, error-prone
Resource parent = mock(Resource.class);
when(parent.getValueMap()).thenReturn(...);

Test Class Structure

package [package].models;

import static org.junit.jupiter.api.Assertions.*;

import org.apache.sling.api.resource.Resource;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;

import com.day.cq.wcm.api.Page;
import io.wcm.testing.mock.aem.junit5.AemContext;
import io.wcm.testing.mock.aem.junit5.AemContextExtension;

// NOTE: Projects MAY have a custom `AppAemContext` helper class that pre-registers
// common services or content. Using `new AemContext()` directly works universally
// with just the wcm.io AEM Mocks dependency.

@ExtendWith(AemContextExtension.class)
class ComponentNameModelTest {

    private final AemContext context = new AemContext();

    private Page page;
    private Resource componentResource;

    @BeforeEach
    void setUp() {
        context.addModelsForClasses(ComponentNameModel.class);
        page = context.create().page("/content/[project]/test-page");
    }

    @Test
    void testWithCompleteData() {
        // Arrange
        componentResource = context.create().resource(page, "component",
            "sling:resourceType", "[project]/components/component-name",
            "title", "Test Title",
            "description", "Test Description");

        // Act
        ComponentNameModel model = componentResource.adaptTo(ComponentNameModel.class);

        // Assert
        assertNotNull(model);
        assertEquals("Test Title", model.getTitle());
        assertEquals("Test Description", model.getDescription());
        assertTrue(model.hasContent());
    }

    @Test
    void testWhenEmpty() {
        componentResource = context.create().resource(page, "component",
            "sling:resourceType", "[project]/components/component-name");

        ComponentNameModel model = componentResource.adaptTo(ComponentNameModel.class);

        assertNotNull(model);
        assertNull(model.getTitle());
        assertFalse(model.hasContent());
    }
}

Test Naming Convention

void testMethodName_Scenario() { }

// Examples:
void testGetTitle_WithValidTitle() { }
void testGetTitle_WhenTitleIsNull() { }
void testHasContent_WithCompleteData() { }
void testHasContent_WhenEmpty() { }
void testGetItems_WithMultipleItems() { }
void testGetItems_WhenNoItems() { }

Required Test Scenarios

For Every Component Model

@Test
void testWithCompleteData() {
    // All properties populated
    // Assert all getters return expected values
    // Assert hasContent() returns true
}

@Test
void testWhenEmpty() {
    // No properties
    // Assert getters return null/empty
    // Assert hasContent() returns false
}

@Test
void testWithPartialData() {
    // Some properties
    // Assert populated properties return values
    // Assert unpopulated return null
}

For Multifield Components

@Test
void testWithMultipleItems() {
    Resource parent = context.create().resource("/content/test", "listTitle", "List");
    context.create().resource("/content/test/items/item0", "itemTitle", "Item 1");
    context.create().resource("/content/test/items/item1", "itemTitle", "Item 2");

    ParentModel model = parent.adaptTo(ParentModel.class);

    assertNotNull(model);
    assertEquals(2, model.getItems().size());
    assertEquals("Item 1", model.getItems().get(0).getItemTitle());
}

@Test
void testWithSingleItem() {
    Resource parent = context.create().resource("/content/test");
    context.create().resource("/content/test/items/item0", "itemTitle", "Only Item");

    ParentModel model = parent.adaptTo(ParentModel.class);

    assertEquals(1, model.getItems().size());
}

@Test
void testWithNoItems() {
    Resource parent = context.create().resource("/content/test");

    ParentModel model = parent.adaptTo(ParentModel.class);

    assertNotNull(model.getItems());
    assertTrue(model.getItems().isEmpty());
}

For Components with Images

@Test
void testImageWithReference() {
    componentResource = context.create().resource(page, "component");
    context.create().resource(componentResource, "image",
        "fileReference", "/content/dam/[project]/image.jpg");

    ComponentModel model = componentResource.adaptTo(ComponentModel.class);

    assertEquals("/content/dam/[project]/image.jpg", model.getImageReference());
}

@Test
void testImageWithoutReference() {
    componentResource = context.create().resource(page, "component");

    ComponentModel model = componentResource.adaptTo(ComponentModel.class);

    assertNull(model.getImageReference());
}

Creating Test Resources

Simple Properties

Resource resource = context.create().resource(page, "component",
    "sling:resourceType", "[project]/components/example",
    "title", "Test Title",
    "description", "Test Description");

Nested Resources (Multifield)

Resource component = context.create().resource(page, "component",
    "sling:resourceType", "[project]/components/example",
    "listTitle", "My List");

context.create().resource(component, "items/item0",
    "title", "Item 1 Title",
    "description", "Item 1 Description");

context.create().resource(component, "items/item1",
    "title", "Item 2 Title");

Image Child Resource

context.create().resource(itemResource, "tileImage",
    "fileReference", "/content/dam/[project]/image.jpg",
    "fileName", "image.jpg");

Assertions

// Null checks
assertNotNull(model);
assertNull(model.getOptionalField());

// Equality
assertEquals("expected", model.getActualValue());
assertEquals(3, model.getItems().size());

// Boolean
assertTrue(model.hasContent());
assertFalse(model.isEmpty());

// Collections
assertNotNull(model.getItems());
assertTrue(model.getItems().isEmpty());

Code Coverage Goals

Minimum 80% line coverage
100% coverage for public methods
Cover all branches (if/else)

Coverage Strategy

Code Pattern	Tests Needed
Simple getter	2 (with value, null)
Conditional (if/else)	2+ (each branch)
Multifield init	4 (null, empty, single, multiple)
Ternary operator	2 (true, false)

Common Mistakes to Avoid

Wrong: Mocking adaptTo()

when(resource.adaptTo(MyModel.class)).thenReturn(mockModel); // FAILS!

Wrong: Not Registering Models

// Returns null without registration
MyModel model = resource.adaptTo(MyModel.class);

Fix: context.addModelsForClasses(MyModel.class)

Wrong: Incorrect Multifield Path

context.create().resource("/content/test/item0"); // Won't be found

Fix: Match dialog structure:

context.create().resource("/content/test/items/item0");

Quick Checklist

Before submitting tests:

All models registered in @BeforeEach
Using context.create().resource() (not mocks)
Multifield paths match dialog structure
Tests cover: complete, empty, partial data
Tests cover: multiple, single, zero items
hasContent() tested for true and false

.tessl-plugin

skills

aem-rde

aem-workflow

content-distribution

create-component

assets

references

aem-conventions.md

clientlib-patterns.md

core-components.md

dialog-patterns.md

examples.md

extending-core-components-example.md

extending-core-components.md

figma-design-rules.md

htl-patterns.md

java-standards.md

model-patterns.md

no-hallucination-rules.md

sling-servlet-standards.md

dispatcher

ensure-agents-md

migration