Add ls-files CLI command

Implement the basic functionality and support the option --help (-h).

Change-Id: Ibcdf0c958d0f93b7415d4e591b1455ccba5d95f7
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
diff --git a/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/LsFilesTest.java b/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/LsFilesTest.java
new file mode 100644
index 0000000..d290206
--- /dev/null
+++ b/org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/LsFilesTest.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2017, Matthias Sohn <matthias.sohn@sap.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.pgm;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.junit.JGitTestUtil;
+import org.eclipse.jgit.lib.CLIRepositoryTestCase;
+import org.eclipse.jgit.util.FileUtils;
+import org.junit.Before;
+import org.junit.Test;
+
+public class LsFilesTest extends CLIRepositoryTestCase {
+
+	@Before
+	@Override
+	public void setUp() throws Exception {
+		super.setUp();
+		try (Git git = new Git(db)) {
+			JGitTestUtil.writeTrashFile(db, "hello", "hello");
+			JGitTestUtil.writeTrashFile(db, "dir", "world", "world");
+			git.add().addFilepattern("dir").call();
+			git.commit().setMessage("Initial commit").call();
+
+			JGitTestUtil.writeTrashFile(db, "hello2", "hello");
+			git.add().addFilepattern("hello2").call();
+			FileUtils.createSymLink(new File(db.getWorkTree(), "link"),
+					"target");
+			FileUtils.mkdir(new File(db.getWorkTree(), "target"));
+			writeTrashFile("target/file", "someData");
+			git.add().addFilepattern("target").addFilepattern("link").call();
+			git.commit().setMessage("hello2").call();
+
+			JGitTestUtil.writeTrashFile(db, "staged", "x");
+			JGitTestUtil.deleteTrashFile(db, "hello2");
+			git.add().addFilepattern("staged").call();
+			JGitTestUtil.writeTrashFile(db, "untracked", "untracked");
+		}
+	}
+
+	@Test
+	public void testHelp() throws Exception {
+		String[] result = execute("git ls-files -h");
+		assertTrue(result[1].startsWith("jgit ls-files"));
+	}
+
+	@Test
+	public void testLsFiles() throws Exception {
+		assertArrayEquals(new String[] { "dir/world", "hello2", "link",
+				"staged", "target/file", "" }, execute("git ls-files"));
+	}
+}
diff --git a/org.eclipse.jgit.pgm/META-INF/services/org.eclipse.jgit.pgm.TextBuiltin b/org.eclipse.jgit.pgm/META-INF/services/org.eclipse.jgit.pgm.TextBuiltin
index 9025473..39fbe2e 100644
--- a/org.eclipse.jgit.pgm/META-INF/services/org.eclipse.jgit.pgm.TextBuiltin
+++ b/org.eclipse.jgit.pgm/META-INF/services/org.eclipse.jgit.pgm.TextBuiltin
@@ -18,6 +18,7 @@
 org.eclipse.jgit.pgm.IndexPack
 org.eclipse.jgit.pgm.Init
 org.eclipse.jgit.pgm.Log
+org.eclipse.jgit.pgm.LsFiles
 org.eclipse.jgit.pgm.LsRemote
 org.eclipse.jgit.pgm.LsTree
 org.eclipse.jgit.pgm.Merge
diff --git a/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties b/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
index e937093..8ff9c6b 100644
--- a/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
+++ b/org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties
@@ -245,6 +245,7 @@
 usage_LFSRunStore=Store (fs | s3), store lfs objects in file system or Amazon S3
 usage_LFSStoreUrl=URL of the LFS store
 usage_LongFormat=Always output the long format
+usage_LsFiles=Show information about files in the index and the working tree
 usage_LsRemote=List references in a remote repository
 usage_lsRemoteHeads=Show only refs starting with refs/heads
 usage_lsRemoteTags=Show only refs starting with refs/tags
diff --git a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/LsFiles.java b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/LsFiles.java
new file mode 100644
index 0000000..dc13000
--- /dev/null
+++ b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/LsFiles.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2017, Matthias Sohn <matthias.sohn@sap.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.pgm;
+
+import static java.util.function.Predicate.isEqual;
+import static org.eclipse.jgit.lib.FileMode.EXECUTABLE_FILE;
+import static org.eclipse.jgit.lib.FileMode.GITLINK;
+import static org.eclipse.jgit.lib.FileMode.REGULAR_FILE;
+import static org.eclipse.jgit.lib.FileMode.SYMLINK;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.eclipse.jgit.dircache.DirCacheIterator;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.FileMode;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.treewalk.CanonicalTreeParser;
+import org.eclipse.jgit.treewalk.TreeWalk;
+import org.eclipse.jgit.treewalk.filter.PathFilterGroup;
+import org.eclipse.jgit.util.QuotedString;
+import org.kohsuke.args4j.Option;
+import org.kohsuke.args4j.spi.StopOptionHandler;
+
+@Command(common = true, usage = "usage_LsFiles")
+class LsFiles extends TextBuiltin {
+
+	@Option(name = "--", metaVar = "metaVar_paths", handler = StopOptionHandler.class)
+	private List<String> paths = new ArrayList<>();
+
+	@Override
+	protected void run() throws Exception {
+		try (RevWalk rw = new RevWalk(db);
+				TreeWalk tw = new TreeWalk(db)) {
+			final ObjectId head = db.resolve(Constants.HEAD);
+			if (head == null) {
+				return;
+			}
+			RevCommit c = rw.parseCommit(head);
+			CanonicalTreeParser p = new CanonicalTreeParser();
+			p.reset(rw.getObjectReader(), c.getTree());
+			tw.reset(); // drop the first empty tree, which we do not need here
+			if (paths.size() > 0) {
+				tw.setFilter(PathFilterGroup.createFromStrings(paths));
+			}
+			tw.addTree(p);
+			tw.addTree(new DirCacheIterator(db.readDirCache()));
+			tw.setRecursive(true);
+			while (tw.next()) {
+				if (filterFileMode(tw, EXECUTABLE_FILE, GITLINK, REGULAR_FILE,
+						SYMLINK)) {
+					outw.println(
+							QuotedString.GIT_PATH.quote(tw.getPathString()));
+				}
+			}
+		}
+	}
+
+	private boolean filterFileMode(TreeWalk tw, FileMode... modes) {
+		return Arrays.stream(modes).anyMatch(isEqual(tw.getFileMode(0))
+				.or(isEqual(tw.getFileMode(1))));
+	}
+}