Harmonize application of method and field filters in search algorithms

This commit consistently applies method predicates in search algorithms
analogous to the application of field predicates.

See junit-team#3498
See junit-team#3532
Closes junit-team#3534

junit-platform-commons/src/main/java/org/junit/platform/commons/util/ReflectionUtils.java

@@ -1407,11 +1407,11 @@ private static Optional<Method> findMethod(Class<?> clazz, Predicate<Method> pre
 
 		for (Class<?> current = clazz; isSearchable(current); current = current.getSuperclass()) {
 			// Search for match in current type
-			List<Method> methods = current.isInterface() ? getMethods(current) : getDeclaredMethods(current, BOTTOM_UP);
-			for (Method method : methods) {
-				if (predicate.test(method)) {
-					return Optional.of(method);
-				}
+			List<Method> methods = current.isInterface() ? getMethods(current, predicate)
+					: getDeclaredMethods(current, predicate, BOTTOM_UP);
+			if (!methods.isEmpty()) {
+				// Since the predicate has already been applied, return the first match.
+				return Optional.of(methods.get(0));
 			}
 
 			// Search for match in interfaces implemented by current type
@@ -1506,8 +1506,8 @@ private static List<Method> findAllMethodsInHierarchy(Class<?> clazz, Predicate<
 		Preconditions.notNull(traversalMode, "HierarchyTraversalMode must not be null");
 
 		// @formatter:off
-		List<Method> localMethods = getDeclaredMethods(clazz, traversalMode).stream()
-				.filter(predicate.and(method -> !method.isSynthetic()))
+		List<Method> localMethods = getDeclaredMethods(clazz, predicate, traversalMode).stream()
+				.filter(method -> !method.isSynthetic())
 				.collect(toList());
 		List<Method> superclassMethods = getSuperclassMethods(clazz, predicate, traversalMode).stream()
 				.filter(method -> !isMethodShadowedByLocalMethods(method, localMethods))
@@ -1550,24 +1550,27 @@ private static List<Field> getDeclaredFields(Class<?> clazz, Predicate<Field> pr
 
 	/**
 	 * Custom alternative to {@link Class#getMethods()} that sorts the methods
-	 * and converts them to a mutable list.
+	 * which match the supplied predicate and converts them to a mutable list.
+	 * @param predicate the method filter; never {@code null}
 	 */
-	private static List<Method> getMethods(Class<?> clazz) {
-		return toSortedMutableList(clazz.getMethods());
+	private static List<Method> getMethods(Class<?> clazz, Predicate<Method> predicate) {
+		return toSortedMutableList(clazz.getMethods(), predicate);
 	}
 
 	/**
 	 * Custom alternative to {@link Class#getDeclaredMethods()} that sorts the
-	 * methods and converts them to a mutable list.
+	 * methods which match the supplied predicate and converts them to a mutable list.
 	 *
 	 * <p>In addition, the list returned by this method includes interface
 	 * default methods which are either prepended or appended to the list of
 	 * declared methods depending on the supplied traversal mode.
 	 */
-	private static List<Method> getDeclaredMethods(Class<?> clazz, HierarchyTraversalMode traversalMode) {
+	private static List<Method> getDeclaredMethods(Class<?> clazz, Predicate<Method> predicate,
+			HierarchyTraversalMode traversalMode) {
+
 		// Note: getDefaultMethods() already sorts the methods,
-		List<Method> defaultMethods = getDefaultMethods(clazz);
-		List<Method> declaredMethods = toSortedMutableList(clazz.getDeclaredMethods());
+		List<Method> defaultMethods = getDefaultMethods(clazz, predicate);
+		List<Method> declaredMethods = toSortedMutableList(clazz.getDeclaredMethods(), predicate);
 
 		// Take the traversal mode into account in order to retain the inherited
 		// nature of interface default methods.
@@ -1584,23 +1587,23 @@ private static List<Method> getDeclaredMethods(Class<?> clazz, HierarchyTraversa
 	/**
 	 * Get a sorted, mutable list of all default methods present in interfaces
 	 * implemented by the supplied class which are also <em>visible</em> within
-	 * the supplied class.
+	 * the supplied class and match the supplied predicate.
 	 *
 	 * @see <a href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-6.html#d5e9652">Method Visibility</a>
 	 * in the Java Language Specification
 	 */
-	private static List<Method> getDefaultMethods(Class<?> clazz) {
+	private static List<Method> getDefaultMethods(Class<?> clazz, Predicate<Method> predicate) {
 		// @formatter:off
 		// Visible default methods are interface default methods that have not
 		// been overridden.
 		List<Method> visibleDefaultMethods = Arrays.stream(clazz.getMethods())
-				.filter(Method::isDefault)
+				.filter(predicate.and(Method::isDefault))
 				.collect(toCollection(ArrayList::new));
 		if (visibleDefaultMethods.isEmpty()) {
 			return visibleDefaultMethods;
 		}
 		return Arrays.stream(clazz.getInterfaces())
-				.map(ReflectionUtils::getMethods)
+				.map(ifc -> getMethods(ifc, predicate))
 				.flatMap(List::stream)
 				.filter(visibleDefaultMethods::contains)
 				.collect(toCollection(ArrayList::new));
@@ -1617,9 +1620,10 @@ private static List<Field> toSortedMutableList(Field[] fields, Predicate<Field>
 		// @formatter:on
 	}
 
-	private static List<Method> toSortedMutableList(Method[] methods) {
+	private static List<Method> toSortedMutableList(Method[] methods, Predicate<Method> predicate) {
 		// @formatter:off
 		return Arrays.stream(methods)
+				.filter(predicate)
 				.sorted(ReflectionUtils::defaultMethodSorter)
 				// Use toCollection() instead of toList() to ensure list is mutable.
 				.collect(toCollection(ArrayList::new));
@@ -1658,8 +1662,8 @@ private static List<Method> getInterfaceMethods(Class<?> clazz, Predicate<Method
 		for (Class<?> ifc : clazz.getInterfaces()) {
 
 			// @formatter:off
-			List<Method> localInterfaceMethods = getMethods(ifc).stream()
-					.filter(predicate.and(method -> !isAbstract(method)))
+			List<Method> localInterfaceMethods = getMethods(ifc, predicate).stream()
+					.filter(method -> !isAbstract(method))
 					.collect(toList());
 
 			List<Method> superinterfaceMethods = getInterfaceMethods(ifc, predicate, traversalMode).stream()