QuarkusComponentTest: convenient handling of nested classes

- add static nested classes declared on test class to the set of
  components under test by default
- exclude static nested classes declated on a QuarkusComponentTest from
  discovery during `@QuarkusTest`

extensions/arc/deployment/src/main/java/io/quarkus/arc/deployment/ArcProcessor.java

@@ -3,6 +3,7 @@
 import static io.quarkus.deployment.annotations.ExecutionTime.RUNTIME_INIT;
 import static io.quarkus.deployment.annotations.ExecutionTime.STATIC_INIT;
 
+import java.lang.reflect.Modifier;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -24,6 +25,7 @@
 
 import org.jboss.jandex.AnnotationTarget;
 import org.jboss.jandex.ClassInfo;
+import org.jboss.jandex.ClassInfo.NestingType;
 import org.jboss.jandex.DotName;
 import org.jboss.jandex.FieldInfo;
 import org.jboss.jandex.IndexView;
@@ -383,6 +385,9 @@ public Integer compute(AnnotationTarget target, Collection<StereotypeInfo> stere
                 builder.addExcludeType(predicate);
             }
         }
+        if (launchModeBuildItem.getLaunchMode() == LaunchMode.TEST) {
+            builder.addExcludeType(createQuarkusComponentTestExcludePredicate(index));
+        }
 
         for (SuppressConditionGeneratorBuildItem generator : suppressConditionGenerators) {
             builder.addSuppressConditionGenerator(generator.getGenerator());
@@ -731,6 +736,39 @@ void registerContextPropagation(ArcConfig config, BuildProducer<ThreadContextPro
         }
     }
 
+    Predicate<ClassInfo> createQuarkusComponentTestExcludePredicate(IndexView index) {
+        // Exlude static nested classed declared on a QuarkusComponentTest:
+        // 1. Test class annotated with @QuarkusComponentTest
+        // 2. Test class with a static field of a type QuarkusComponentTestExtension
+        DotName quarkusComponentTest = DotName.createSimple("io.quarkus.test.component.QuarkusComponentTest");
+        DotName quarkusComponentTestExtension = DotName.createSimple("io.quarkus.test.component.QuarkusComponentTestExtension");
+        return new Predicate<ClassInfo>() {
+
+            @Override
+            public boolean test(ClassInfo clazz) {
+                if (clazz.nestingType() == NestingType.INNER
+                        && Modifier.isStatic(clazz.flags())) {
+                    DotName enclosingClassName = clazz.enclosingClass();
+                    ClassInfo enclosingClass = index.getClassByName(enclosingClassName);
+                    if (enclosingClass != null) {
+                        if (enclosingClass.hasDeclaredAnnotation(quarkusComponentTest)) {
+                            return true;
+                        } else {
+                            for (FieldInfo field : enclosingClass.fields()) {
+                                if (!field.isSynthetic()
+                                        && Modifier.isStatic(field.flags())
+                                        && field.type().name().equals(quarkusComponentTestExtension)) {
+                                    return true;
+                                }
+                            }
+                        }
+                    }
+                }
+                return false;
+            }
+        };
+    }
+
     private abstract static class AbstractCompositeApplicationClassesPredicate<T> implements Predicate<T> {
 
         private final IndexView applicationClassesIndex;

integration-tests/main/pom.xml

@@ -154,6 +154,11 @@
             <artifactId>quarkus-junit5</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit5-component</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>io.quarkus</groupId>
             <artifactId>quarkus-test-h2</artifactId>

integration-tests/main/src/test/java/io/quarkus/it/main/MyComponentTest.java

@@ -0,0 +1,39 @@
+package io.quarkus.it.main;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import jakarta.enterprise.inject.Produces;
+import jakarta.inject.Inject;
+import jakarta.inject.Singleton;
+
+import org.eclipse.microprofile.config.inject.ConfigProperty;
+import org.junit.jupiter.api.Test;
+
+import io.quarkus.test.component.QuarkusComponentTest;
+
+@QuarkusComponentTest
+public class MyComponentTest {
+
+    @Inject
+    @ConfigProperty // name and default value are nonbinding
+    String myProperty;
+
+    @Test
+    public void testProperty() {
+        assertEquals("foo", myProperty);
+    }
+
+    @Singleton
+    static class PropertyProducer {
+
+        // This producer would normally break all @QuarkusTest in the test suite
+        // However, since it's a static nested class declared on a @QuarkusComponentTest it's excluded from the bean discovery
+        @Produces
+        @ConfigProperty
+        String myString() {
+            return "foo";
+        }
+
+    }
+
+}

test-framework/junit5-component/src/main/java/io/quarkus/test/component/QuarkusComponentTest.java

@@ -43,4 +43,11 @@
      * @see QuarkusComponentTestExtension#useDefaultConfigProperties()
      */
     boolean useDefaultConfigProperties() default false;
+
+    /**
+     * If set to {@code true} then all static nested classes are considered additional components under test.
+     *
+     * @see #value()
+     */
+    boolean addNestedClassesAsComponents() default true;
 }

test-framework/junit5-component/src/main/java/io/quarkus/test/component/QuarkusComponentTestExtension.java

@@ -7,6 +7,7 @@
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
 import java.lang.reflect.Parameter;
 import java.lang.reflect.ParameterizedType;
 import java.nio.file.Files;
@@ -65,6 +66,7 @@
 import io.quarkus.arc.ArcContainer;
 import io.quarkus.arc.ComponentsProvider;
 import io.quarkus.arc.InstanceHandle;
+import io.quarkus.arc.Unremovable;
 import io.quarkus.arc.processor.Annotations;
 import io.quarkus.arc.processor.AnnotationsTransformer;
 import io.quarkus.arc.processor.BeanArchives;
@@ -151,6 +153,7 @@ public class QuarkusComponentTestExtension
     private final List<Class<?>> additionalComponentClasses;
     private final List<MockBeanConfiguratorImpl<?>> mockConfigurators;
     private final AtomicBoolean useDefaultConfigProperties = new AtomicBoolean();
+    private final AtomicBoolean addNestedClassesAsComponents = new AtomicBoolean(true);
 
     // Used for declarative registration
     public QuarkusComponentTestExtension() {
@@ -209,6 +212,19 @@ public QuarkusComponentTestExtension useDefaultConfigProperties() {
         return this;
     }
 
+    /**
+     * Ignore the static nested classes declared on the test class.
+     * <p>
+     * By default, all static nested classes declared on the test class are added to the set of additional components under
+     * test.
+     *
+     * @return the extension
+     */
+    public QuarkusComponentTestExtension ignoreNestedClasses() {
+        this.addNestedClassesAsComponents.set(false);
+        return this;
+    }
+
     @Override
     public void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception {
         long start = System.nanoTime();
@@ -247,6 +263,7 @@ public void beforeAll(ExtensionContext context) throws Exception {
             if (testAnnotation.useDefaultConfigProperties()) {
                 this.useDefaultConfigProperties.set(true);
             }
+            this.addNestedClassesAsComponents.set(testAnnotation.addNestedClassesAsComponents());
         }
         // All fields annotated with @Inject represent component classes
         Class<?> current = testClass;
@@ -258,6 +275,14 @@ public void beforeAll(ExtensionContext context) throws Exception {
             }
             current = current.getSuperclass();
         }
+        // All static nested classes declared on the test class are components
+        if (this.addNestedClassesAsComponents.get()) {
+            for (Class<?> declaredClass : testClass.getDeclaredClasses()) {
+                if (Modifier.isStatic(declaredClass.getModifiers())) {
+                    componentClasses.add(declaredClass);
+                }
+            }
+        }
 
         TestConfigProperty[] testConfigProperties = testClass.getAnnotationsByType(TestConfigProperty.class);
         for (TestConfigProperty testConfigProperty : testConfigProperties) {
@@ -468,7 +493,13 @@ private ClassLoader initArcContainer(ExtensionContext context, Collection<Class<
             BeanProcessor.Builder builder = BeanProcessor.builder()
                     .setName(testClass.getName().replace('.', '_'))
                     .addRemovalExclusion(b -> {
-                        // Do not remove beans injected in the test class
+                        // Do not remove beans:
+                        // 1. Injected in the test class
+                        // 2. Annotated with @Unremovable
+                        if (b.getTarget().isPresent()
+                                && b.getTarget().get().hasDeclaredAnnotation(Unremovable.class)) {
+                            return true;
+                        }
                         for (Field injectionPoint : testClassInjectionPoints) {
                             if (beanResolver.get().matches(b, Types.jandexType(injectionPoint.getGenericType()),
                                     getQualifiers(injectionPoint, qualifiers))) {

test-framework/junit5-component/src/test/java/io/quarkus/test/component/MockNotSharedForClassHierarchyTest.java

@@ -15,7 +15,8 @@
 public class MockNotSharedForClassHierarchyTest {
 
     @RegisterExtension
-    static final QuarkusComponentTestExtension extension = new QuarkusComponentTestExtension(Component.class);
+    static final QuarkusComponentTestExtension extension = new QuarkusComponentTestExtension(Component.class)
+            .ignoreNestedClasses();
 
     @Inject
     Component component;

test-framework/junit5-component/src/test/java/io/quarkus/test/component/MockSharedForClassHierarchyTest.java

@@ -16,7 +16,7 @@ public class MockSharedForClassHierarchyTest {
     static final QuarkusComponentTestExtension extension = new QuarkusComponentTestExtension(Component.class).mock(Foo.class)
             .createMockitoMock(foo -> {
                 Mockito.when(foo.ping()).thenReturn(11);
-            });
+            }).ignoreNestedClasses();
 
     @Inject
     Component component;

test-framework/junit5-component/src/test/java/io/quarkus/test/component/declarative/IgnoreNestedClassesTest.java

@@ -0,0 +1,36 @@
+package io.quarkus.test.component.declarative;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import jakarta.inject.Singleton;
+
+import org.junit.jupiter.api.Test;
+
+import io.quarkus.arc.Arc;
+import io.quarkus.arc.Unremovable;
+import io.quarkus.test.component.QuarkusComponentTest;
+import io.quarkus.test.component.declarative.IgnoreNestedClassesTest.Alpha;
+
+@QuarkusComponentTest(value = Alpha.class, addNestedClassesAsComponents = false)
+public class IgnoreNestedClassesTest {
+
+    @Test
+    public void testComponents() {
+        assertTrue(Arc.container().instance(Alpha.class).isAvailable());
+        assertFalse(Arc.container().instance(Bravo.class).isAvailable());
+    }
+
+    @Unremovable
+    @Singleton
+    static class Alpha {
+
+    }
+
+    @Unremovable
+    @Singleton
+    static class Bravo {
+
+    }
+
+}

test-framework/junit5-component/src/test/java/io/quarkus/test/component/declarative/InterceptorMockingTest.java

@@ -0,0 +1,74 @@
+package io.quarkus.test.component.declarative;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import jakarta.annotation.Priority;
+import jakarta.inject.Inject;
+import jakarta.inject.Singleton;
+import jakarta.interceptor.AroundInvoke;
+import jakarta.interceptor.Interceptor;
+import jakarta.interceptor.InterceptorBinding;
+import jakarta.interceptor.InvocationContext;
+
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+import io.quarkus.test.InjectMock;
+import io.quarkus.test.component.QuarkusComponentTest;
+import io.quarkus.test.component.beans.Charlie;
+
+@QuarkusComponentTest
+public class InterceptorMockingTest {
+
+    @Inject
+    TheComponent theComponent;
+
+    @InjectMock
+    Charlie charlie;
+
+    @Test
+    public void testPing() {
+        Mockito.when(charlie.ping()).thenReturn("ok");
+        assertEquals("ok", theComponent.ping());
+    }
+
+    @Singleton
+    static class TheComponent {
+
+        @SimpleBinding
+        String ping() {
+            return "true";
+        }
+
+    }
+
+    @Target({ TYPE, METHOD })
+    @Retention(RUNTIME)
+    @InterceptorBinding
+    public @interface SimpleBinding {
+
+    }
+
+    // This interceptor is automatically added as a tested component
+    @Priority(1)
+    @SimpleBinding
+    @Interceptor
+    static class SimpleInterceptor {
+
+        @Inject
+        Charlie charlie;
+
+        @AroundInvoke
+        Object aroundInvoke(InvocationContext context) throws Exception {
+            return Boolean.parseBoolean(context.proceed().toString()) ? charlie.ping() : "false";
+        }
+
+    }
+
+}