Add classpath scanning support for non-public test methods

Fixes #16.

src/main/java/org/junit/support/testng/engine/IsTestNGTestClass.java

@@ -10,9 +10,13 @@
 
 package org.junit.support.testng.engine;
 
-import java.util.Arrays;
+import java.lang.reflect.Method;
+import java.util.List;
 import java.util.function.Predicate;
 
+import org.junit.platform.commons.support.HierarchyTraversalMode;
+import org.junit.platform.commons.support.ReflectionSupport;
+
 class IsTestNGTestClass implements Predicate<Class<?>> {
 
 	@Override
@@ -22,6 +26,8 @@ public boolean test(Class<?> candidateClass) {
 	}
 
 	private boolean hasMethodWithTestAnnotation(Class<?> candidateClass) {
-		return Arrays.stream(candidateClass.getMethods()).anyMatch(TestAnnotationUtils::isAnnotatedDirectly);
+		List<Method> testMethods = ReflectionSupport.findMethods(candidateClass,
+			TestAnnotationUtils::isAnnotatedDirectly, HierarchyTraversalMode.BOTTOM_UP);
+		return !testMethods.isEmpty();
 	}
 }

src/test/java/org/junit/support/testng/engine/DiscoveryIntegrationTests.java

@@ -326,6 +326,52 @@ void ignoresAnonymousClasses() {
 		assertThat(rootDescriptor.getChildren()).isEmpty();
 	}
 
+	@Test
+	void discoversAllTestMethodsForDefaultVisibilityWithDeclaredMethodTestCase() {
+		var request = request() //
+				.selectors(selectPackage("example.basics")) //
+				.filters(includeClassNamePatterns(".+\\.DefaultVisibilityWithDeclaredMethodTestCase")) //
+				.build();
+
+		var rootDescriptor = testEngine.discover(request, engineId);
+
+		assertThat(rootDescriptor.getUniqueId()).isEqualTo(engineId);
+		assertThat(rootDescriptor.getChildren()).hasSize(1);
+
+		TestDescriptor classDescriptor = getOnlyElement(rootDescriptor.getChildren());
+		assertThat(classDescriptor.getDisplayName()).isEqualTo("DefaultVisibilityWithDeclaredMethodTestCase");
+		assertThat(classDescriptor.getLegacyReportingName()).isEqualTo(
+			"example.basics.DefaultVisibilityWithDeclaredMethodTestCase");
+		assertThat(classDescriptor.getType()).isEqualTo(CONTAINER);
+		assertThat(classDescriptor.getSource()).containsInstanceOf(ClassSource.class);
+		assertThat(classDescriptor.getChildren()) //
+				.extracting(TestDescriptor::getDisplayName) //
+				.containsExactlyInAnyOrder("baseMethod", "declaredMethod");
+	}
+
+	@Test
+	void discoversAllTestMethodsForDefaultVisibilityWithoutDeclaredMethodTestCase() {
+		var request = request() //
+				.selectors(selectPackage("example.basics")) //
+				.filters(includeClassNamePatterns(".+\\.DefaultVisibilityWithoutDeclaredMethodTestCase")) //
+				.build();
+
+		var rootDescriptor = testEngine.discover(request, engineId);
+
+		assertThat(rootDescriptor.getUniqueId()).isEqualTo(engineId);
+		assertThat(rootDescriptor.getChildren()).hasSize(1);
+
+		TestDescriptor classDescriptor = getOnlyElement(rootDescriptor.getChildren());
+		assertThat(classDescriptor.getDisplayName()).isEqualTo("DefaultVisibilityWithoutDeclaredMethodTestCase");
+		assertThat(classDescriptor.getLegacyReportingName()).isEqualTo(
+			"example.basics.DefaultVisibilityWithoutDeclaredMethodTestCase");
+		assertThat(classDescriptor.getType()).isEqualTo(CONTAINER);
+		assertThat(classDescriptor.getSource()).containsInstanceOf(ClassSource.class);
+		assertThat(classDescriptor.getChildren()) //
+				.extracting(TestDescriptor::getDisplayName) //
+				.containsExactlyInAnyOrder("baseMethod");
+	}
+
 	interface InterfaceTestCase {
 	}
 

src/testFixtures/java/example/basics/DefaultVisibilityBaseTestCase.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * https://www.eclipse.org/legal/epl-v20.html
+ */
+
+package example.basics;
+
+import org.testng.annotations.Test;
+
+abstract class DefaultVisibilityBaseTestCase {
+
+	@Test
+	void baseMethod() {
+	}
+
+}

src/testFixtures/java/example/basics/DefaultVisibilityWithDeclaredMethodTestCase.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * https://www.eclipse.org/legal/epl-v20.html
+ */
+
+package example.basics;
+
+import org.testng.annotations.Test;
+
+class DefaultVisibilityWithDeclaredMethodTestCase extends DefaultVisibilityBaseTestCase {
+
+	@Test
+	void declaredMethod() {
+	}
+
+}

src/testFixtures/java/example/basics/DefaultVisibilityWithoutDeclaredMethodTestCase.java

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * https://www.eclipse.org/legal/epl-v20.html
+ */
+
+package example.basics;
+
+class DefaultVisibilityWithoutDeclaredMethodTestCase extends DefaultVisibilityBaseTestCase {
+}