Allow publishing files to an existing directory

Prior to this commit, both `TestReporter` and `ExtensionContext` threw
an exception when `publishDirectory` was called with an existing
directory. Now, they only attempt to create the directory if it doesn't
already exist.

Author: marcphilipp

documentation/src/docs/asciidoc/release-notes/release-notes-5.13.0.adoc

@@ -188,6 +188,8 @@ to start reporting discovery issues.
   failures.
 * Add support for Kotlin `Sequence` to `@MethodSource`, `@FieldSource`, and
   `@TestFactory`.
+* Allow publishing files to an existing directory via `TestReporter` and
+  `ExtensionContext`, for example, when re-running a test class.
 
 
 [[release-notes-5.13.0-junit-vintage]]

junit-jupiter-api/src/main/java/org/junit/jupiter/api/extension/ExtensionContext.java

@@ -419,7 +419,7 @@ default void publishReportEntry(String value) {
 	 * and attach it to the current test or container.
 	 *
 	 * <p>The directory will be resolved and created in the report output directory
-	 * prior to invoking the supplied action.
+	 * prior to invoking the supplied action, if it doesn't already exist.
 	 *
 	 * @param name the name of the directory to be attached; never {@code null}
 	 * or blank and must not contain any path separators

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/AbstractExtensionContext.java

@@ -161,7 +161,9 @@ public void publishDirectory(String name, ThrowingConsumer<Path> action) {
 		Preconditions.notNull(action, "action must not be null");
 
 		ThrowingConsumer<Path> enhancedAction = path -> {
-			Files.createDirectory(path);
+			if (!Files.isDirectory(path)) {
+				Files.createDirectory(path);
+			}
 			action.accept(path);
 		};
 		publishFileEntry(name, enhancedAction, file -> {

jupiter-tests/src/test/java/org/junit/jupiter/engine/descriptor/ExtensionContextTests.java

@@ -382,6 +382,19 @@ void failsWhenAttemptingToPublishRegularFilesAsDirectories(@TempDir Path tempDir
 			"Published path must be a directory: " + tempDir.resolve("OuterClass").resolve("test"));
 	}
 
+	@Test
+	void allowsPublishingToTheSameDirectoryTwice(@TempDir Path tempDir) {
+		var extensionContext = createExtensionContextForFilePublishing(tempDir);
+
+		extensionContext.publishDirectory("test",
+			dir -> Files.writeString(dir.resolve("nested1.txt"), "Nested content 1"));
+		extensionContext.publishDirectory("test",
+			dir -> Files.writeString(dir.resolve("nested2.txt"), "Nested content 2"));
+
+		assertThat(tempDir.resolve("OuterClass/test/nested1.txt")).hasContent("Nested content 1");
+		assertThat(tempDir.resolve("OuterClass/test/nested2.txt")).hasContent("Nested content 2");
+	}
+
 	private ExtensionContext createExtensionContextForFilePublishing(Path tempDir) {
 		return createExtensionContextForFilePublishing(tempDir, mock(EngineExecutionListener.class),
 			outerClassDescriptor(null));