}

  public void testFileTraverser_emptyDirectory() throws Exception {
    assertThat(Files.fileTraverser().breadthFirst(rootDir)).containsExactly(rootDir);
  }

  public void testFileTraverser_nonExistingFile() throws Exception {
    File file = new File(rootDir, "file-that-doesnt-exist");

    assertThat(Files.fileTraverser().breadthFirst(file)).containsExactly(file);
  }

  public void testFileTraverser_file() throws Exception {

   * single element: that file.
   *
   * <p>Example: {@code Files.fileTraverser().depthFirstPreOrder(new File("/"))} may return files
   * with the following paths: {@code ["/", "/etc", "/etc/config.txt", "/etc/fonts", "/home",
   * "/home/alice", ...]}
   *
   * @since 23.5
   */
  public static Traverser<File> fileTraverser() {
    return Traverser.forTree(FILE_TREE);
  }

   * single element: that file.
   *
   * <p>Example: {@code Files.fileTraverser().depthFirstPreOrder(new File("/"))} may return files
   * with the following paths: {@code ["/", "/etc", "/etc/config.txt", "/etc/fonts", "/home",
   * "/home/alice", ...]}
   *
   * @since 23.5
   */
  public static Traverser<File> fileTraverser() {
    return Traverser.forTree(FILE_TREE);
  }

import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link Files}.
 *
 * <p>Some methods are tested in separate files:
 *
 * <ul>
 *   <li>{@link Files#fileTraverser()} is tested in {@link FilesFileTraverserTest}.
 *   <li>{@link Files#createTempDir()} is tested in {@link FilesCreateTempDirTest}.
 * </ul>
 *
 * @author Chris Nokleberg
 */

import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link Files}.
 *
 * <p>Some methods are tested in separate files:
 *
 * <ul>
 *   <li>{@link Files#fileTraverser()} is tested in {@link FilesFileTraverserTest}.
 *   <li>{@link Files#createTempDir()} is tested in {@link FilesCreateTempDirTest}.
 * </ul>
 *
 * @author Chris Nokleberg
 */