CleanCommand: add the ability to do a dry run

Change-Id: I7b81a7e34a771951e2e7b789b080b2bfb8656e5c
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CleanCommandTest.java

@@ -113,4 +113,23 @@ public class CleanCommandTest extends RepositoryTestCase {
 		assertTrue(!cleanedFiles.contains("File2.txt"));
 	}
 
+	@Test
+	public void testCleanWithDryRun() throws NoWorkTreeException, IOException {
+		// create status
+		StatusCommand command = git.status();
+		Status status = command.call();
+		Set<String> files = status.getUntracked();
+		assertTrue(files.size() > 0);
+
+		// run clean
+		Set<String> cleanedFiles = git.clean().setDryRun(true).call();
+
+		status = git.status().call();
+		files = status.getUntracked();
+
+		assertTrue(files.size() == 2);
+		assertTrue(cleanedFiles.contains("File2.txt"));
+		assertTrue(cleanedFiles.contains("File3.txt"));
+	}
+
 }

org.eclipse.jgit/src/org/eclipse/jgit/api/CleanCommand.java

@@ -64,6 +64,8 @@ public class CleanCommand extends GitCommand<Set<String>> {
 
 	private Set<String> paths = Collections.emptySet();
 
+	private boolean dryRun;
+
 	/**
 	 * @param repo
 	 */
@@ -86,7 +88,8 @@ public class CleanCommand extends GitCommand<Set<String>> {
 			Status status = command.call();
 			for (String file : status.getUntracked()) {
 				if (paths.isEmpty() || paths.contains(file)) {
-					FileUtils.delete(new File(repo.getWorkTree(), file));
+					if (!dryRun)
+						FileUtils.delete(new File(repo.getWorkTree(), file));
 					files.add(file);
 				}
 			}
@@ -108,4 +111,15 @@ public class CleanCommand extends GitCommand<Set<String>> {
 		return this;
 	}
 
+	/**
+	 * If dryRun is set, the paths in question will not actually be deleted.
+	 * 
+	 * @param dryRun
+	 *            whether to do a dry run or not
+	 * @return {@code this}
+	 */
+	public CleanCommand setDryRun(boolean dryRun) {
+		this.dryRun = dryRun;
+		return this;
+	}
 }