Move more common logic into SearchPathUtils

Author: marcphilipp

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

@@ -11,6 +11,9 @@
 package org.junit.platform.commons.util;
 
 import static java.util.stream.Collectors.joining;
+import static org.junit.platform.commons.util.SearchPathUtils.PACKAGE_SEPARATOR_CHAR;
+import static org.junit.platform.commons.util.SearchPathUtils.PACKAGE_SEPARATOR_STRING;
+import static org.junit.platform.commons.util.SearchPathUtils.determineSimpleClassName;
 import static org.junit.platform.commons.util.StringUtils.isNotBlank;
 
 import java.io.IOException;
@@ -31,7 +34,6 @@
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 
-import org.junit.platform.commons.JUnitException;
 import org.junit.platform.commons.PreconditionViolationException;
 import org.junit.platform.commons.function.Try;
 import org.junit.platform.commons.io.Resource;
@@ -57,8 +59,6 @@ class DefaultClasspathScanner implements ClasspathScanner {
 	private static final char CLASSPATH_RESOURCE_PATH_SEPARATOR = '/';
 	private static final String CLASSPATH_RESOURCE_PATH_SEPARATOR_STRING = String.valueOf(
 		CLASSPATH_RESOURCE_PATH_SEPARATOR);
-	private static final char PACKAGE_SEPARATOR_CHAR = '.';
-	private static final String PACKAGE_SEPARATOR_STRING = String.valueOf(PACKAGE_SEPARATOR_CHAR);
 
 	/**
 	 * Malformed class name InternalError like reported in #401.
@@ -132,7 +132,7 @@ private List<Class<?>> findClassesForUris(List<URI> baseUris, String basePackage
 	private List<Class<?>> findClassesForUri(URI baseUri, String basePackageName, ClassFilter classFilter) {
 		List<Class<?>> classes = new ArrayList<>();
 		// @formatter:off
-		walkFilesForUri(baseUri, ClasspathFilters.classFiles(),
+		walkFilesForUri(baseUri, SearchPathUtils::isClassOrSourceFile,
 				(baseDir, file) ->
 						processClassFileSafely(baseDir, basePackageName, classFilter, file, classes::add));
 		// @formatter:on
@@ -156,7 +156,7 @@ private List<Resource> findResourcesForUris(List<URI> baseUris, String basePacka
 	private List<Resource> findResourcesForUri(URI baseUri, String basePackageName, ResourceFilter resourceFilter) {
 		List<Resource> resources = new ArrayList<>();
 		// @formatter:off
-		walkFilesForUri(baseUri, ClasspathFilters.resourceFiles(),
+		walkFilesForUri(baseUri, SearchPathUtils::isResourceFile,
 				(baseDir, file) ->
 						processResourceFileSafely(baseDir, basePackageName, resourceFilter, file, resources::add));
 		// @formatter:on
@@ -253,19 +253,6 @@ private String determineFullyQualifiedResourceName(Path baseDir, String basePack
 		// @formatter:on
 	}
 
-	private String determineSimpleClassName(Path file) {
-		String fileName = file.getFileName().toString();
-		return determineSimpleClassName(fileName);
-	}
-
-	static String determineSimpleClassName(String fileName) {
-		int lastDot = fileName.lastIndexOf('.');
-		if (lastDot < 0) {
-			throw new JUnitException("Expected file name with file extension, but got: " + fileName);
-		}
-		return fileName.substring(0, lastDot);
-	}
-
 	private String determineSimpleResourceName(Path resourceFile) {
 		return resourceFile.getFileName().toString();
 	}

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

@@ -24,6 +24,7 @@
 import java.lang.module.ResolvedModule;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -253,11 +254,10 @@ List<Class<?>> scan(ModuleReference reference) {
 			try (ModuleReader reader = reference.open()) {
 				try (Stream<String> names = reader.list()) {
 					// @formatter:off
-					return names.filter(ClasspathFilters::isClassOrSourceFileName)
-							.map(DefaultClasspathScanner::determineSimpleClassName)
-							.map(name -> name.replace('/', '.'))
-							.filter(name -> !"module-info".equals(name))
-							.filter(name -> !name.endsWith("package-info"))
+					return names.filter(name -> !name.endsWith("/")) // remove directories
+							.map(Path::of)
+							.filter(SearchPathUtils::isClassOrSourceFile)
+							.map(SearchPathUtils::determineFullyQualifiedClassName)
 							.filter(classFilter::match)
 							.<Class<?>> map(this::loadClassUnchecked)
 							.filter(classFilter::match)

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

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2015-2025 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 org.junit.platform.commons.util;
+
+import static java.util.stream.Collectors.joining;
+
+import java.nio.file.Path;
+import java.util.stream.IntStream;
+
+import org.junit.platform.commons.JUnitException;
+
+/**
+ * @since 1.11
+ */
+class SearchPathUtils {
+
+	static final char PACKAGE_SEPARATOR_CHAR = '.';
+	static final String PACKAGE_SEPARATOR_STRING = String.valueOf(PACKAGE_SEPARATOR_CHAR);
+	private static final char FILE_NAME_EXTENSION_SEPARATOR_CHAR = '.';
+
+	private static final String CLASS_FILE_SUFFIX = ".class";
+	private static final String SOURCE_FILE_SUFFIX = ".java";
+
+	private static final String PACKAGE_INFO_FILE_NAME = "package-info";
+	private static final String MODULE_INFO_FILE_NAME = "module-info";
+
+	// System property defined since Java 12: https://bugs.java/bugdatabase/JDK-8210877
+	private static final boolean SOURCE_MODE = System.getProperty("jdk.launcher.sourcefile") != null;
+
+	static boolean isResourceFile(Path file) {
+		return !isClassFile(file);
+	}
+
+	static boolean isClassOrSourceFile(Path file) {
+		var fileName = file.getFileName().toString();
+		return isClassOrSourceFile(fileName) && !isModuleInfoOrPackageInfo(fileName);
+	}
+
+	private static boolean isModuleInfoOrPackageInfo(String fileName) {
+		var fileNameWithoutExtension = removeExtension(fileName);
+		return PACKAGE_INFO_FILE_NAME.equals(fileNameWithoutExtension) //
+				|| MODULE_INFO_FILE_NAME.equals(fileNameWithoutExtension);
+	}
+
+	static String determineFullyQualifiedClassName(Path path) {
+		var simpleClassName = determineSimpleClassName(path);
+		var parent = path.getParent();
+		return parent == null ? simpleClassName : joinPathNamesWithPackageSeparator(parent.resolve(simpleClassName));
+	}
+
+	private static String joinPathNamesWithPackageSeparator(Path path) {
+		return IntStream.range(0, path.getNameCount()) //
+				.mapToObj(i -> path.getName(i).toString()) //
+				.collect(joining(PACKAGE_SEPARATOR_STRING));
+	}
+
+	static String determineSimpleClassName(Path file) {
+		return removeExtension(file.getFileName().toString());
+	}
+
+	private static String removeExtension(String fileName) {
+		int lastDot = fileName.lastIndexOf(FILE_NAME_EXTENSION_SEPARATOR_CHAR);
+		if (lastDot < 0) {
+			throw new JUnitException("Expected file name with file extension, but got: " + fileName);
+		}
+		return fileName.substring(0, lastDot);
+	}
+
+	private static boolean isClassOrSourceFile(String name) {
+		return name.endsWith(CLASS_FILE_SUFFIX) || (SOURCE_MODE && name.endsWith(SOURCE_FILE_SUFFIX));
+	}
+
+	private static boolean isClassFile(Path file) {
+		return file.getFileName().toString().endsWith(CLASS_FILE_SUFFIX);
+	}
+
+	private SearchPathUtils() {
+	}
+}

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

@@ -103,7 +103,7 @@ void junitRunClass(@FilePrefix("junit-run-class") OutputFiles outputFiles) throw
 
 	@Test
 	@EnabledOnJre(JRE.JAVA_25)
-	void junitRunModule(@FilePrefix("junit-run-Module") OutputFiles outputFiles) throws Exception {
+	void junitRunModule(@FilePrefix("junit-run-module") OutputFiles outputFiles) throws Exception {
 		var result = ProcessStarters.java() //
 				.workingDir(workspace) //
 				.putEnvironment("NO_COLOR", "1") // --disable-ansi-colors