Set readonly attribute to false if DosFileAttributeView is supported

documentation/src/docs/asciidoc/release-notes/release-notes-5.10.0-RC1.adoc

@@ -64,6 +64,8 @@ JUnit repository on GitHub.
   the documentation for extension registration via `@ExtendWith` on fields.
 * The scope of applicability for `TestWatcher` implementations is now more extensively
   documented in the User Guide and Javadoc.
+* `@TempDir` now successfully cleans up files and directories on Windows that are set to
+  read-only.
 
 
 [[release-notes-5.10.0-RC1-junit-vintage]]

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/extension/TempDirectory.java

@@ -33,6 +33,7 @@
 import java.nio.file.Paths;
 import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
+import java.nio.file.attribute.DosFileAttributeView;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
@@ -390,6 +391,15 @@ private static void tryToResetPermissions(Path path) {
 			if (Files.isDirectory(path)) {
 				file.setExecutable(true);
 			}
+			DosFileAttributeView dos = Files.getFileAttributeView(path, DosFileAttributeView.class);
+			if (dos != null) {
+				try {
+					dos.setReadOnly(false);
+				}
+				catch (IOException ignore) {
+					// nothing we can do
+				}
+			}
 		}
 
 		private IOException createIOExceptionWithAttachedFailures(SortedMap<Path, IOException> failures) {

junit-jupiter-engine/src/test/java/org/junit/jupiter/engine/extension/TempDirectoryPerContextTests.java

@@ -30,6 +30,7 @@
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.attribute.DosFileAttributeView;
 import java.util.Deque;
 import java.util.LinkedList;
 import java.util.function.Supplier;
@@ -47,8 +48,6 @@
 import org.junit.jupiter.api.TestInfo;
 import org.junit.jupiter.api.TestInstance;
 import org.junit.jupiter.api.TestMethodOrder;
-import org.junit.jupiter.api.condition.DisabledOnOs;
-import org.junit.jupiter.api.condition.OS;
 import org.junit.jupiter.api.extension.ExtensionConfigurationException;
 import org.junit.jupiter.api.extension.ExtensionContext;
 import org.junit.jupiter.api.extension.ParameterResolutionException;
@@ -126,15 +125,13 @@ void nonMintPermissionsDoNotCauseFailure() {
 	}
 
 	@Test
-	@DisabledOnOs(OS.WINDOWS)
 	@DisplayName("is capable of removing a read-only file in a read-only dir")
 	void readOnlyFileInReadOnlyDirDoesNotCauseFailure() {
 		executeTestsForClass(ReadOnlyFileInReadOnlyDirDoesNotCauseFailureTestCase.class).testEvents()//
 				.assertStatistics(stats -> stats.started(1).succeeded(1));
 	}
 
 	@Test
-	@DisabledOnOs(OS.WINDOWS)
 	@DisplayName("is capable of removing a read-only file in a dir in a read-only dir")
 	void readOnlyFileInNestedReadOnlyDirDoesNotCauseFailure() {
 		executeTestsForClass(ReadOnlyFileInDirInReadOnlyDirDoesNotCauseFailureTestCase.class).testEvents()//
@@ -942,8 +939,8 @@ static class ReadOnlyFileInReadOnlyDirDoesNotCauseFailureTestCase {
 		void createReadOnlyFileInReadOnlyDir(@TempDir File tempDir) throws IOException {
 			File file = tempDir.toPath().resolve("file").toFile();
 			assumeTrue(file.createNewFile());
-			assumeTrue(tempDir.setReadOnly());
-			assumeTrue(file.setReadOnly());
+			assumeTrue(makeReadOnly(tempDir));
+			assumeTrue(makeReadOnly(file));
 		}
 
 	}
@@ -956,13 +953,22 @@ void createReadOnlyFileInReadOnlyDir(@TempDir File tempDir) throws IOException {
 			File file = tempDir.toPath().resolve("dir").resolve("file").toFile();
 			assumeTrue(file.getParentFile().mkdirs());
 			assumeTrue(file.createNewFile());
-			assumeTrue(tempDir.setReadOnly());
-			assumeTrue(file.getParentFile().setReadOnly());
-			assumeTrue(file.setReadOnly());
+			assumeTrue(makeReadOnly(tempDir));
+			assumeTrue(makeReadOnly(file.getParentFile()));
+			assumeTrue(makeReadOnly(file));
 		}
 
 	}
 
+	private static boolean makeReadOnly(File file) throws IOException {
+		var dos = Files.getFileAttributeView(file.toPath(), DosFileAttributeView.class);
+		if (dos != null) {
+			dos.setReadOnly(true);
+			return true;
+		}
+		return file.setReadOnly();
+	}
+
 	// https://github.com/junit-team/junit5/issues/2609
 	@SuppressWarnings("ResultOfMethodCallIgnored")
 	static class NonMintPermissionContentInTempDirectoryDoesNotCauseFailureTestCase {