Added API to TextBuiltin for piped usage.

Added a public method to TextBuiltin which makes it possible for
clients to initialize all of its state, including output and error
streams.  This gives clients the ability to customize the way in
which a command is run.

Change-Id: If718236964d2c5cf869e120c74f1a12965f4812e
Signed-off-by: Ned Twigg <ned.twigg@diffplug.com>

org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/TextBuiltinTest.java

@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2017, Ned Twigg <ned.twigg@diffplug.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.eclipse.jgit.junit.JGitTestUtil.check;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.lib.CLIRepositoryTestCase;
+import org.eclipse.jgit.pgm.opt.CmdLineParser;
+import org.eclipse.jgit.pgm.opt.SubcommandHandler;
+import org.junit.Test;
+import org.kohsuke.args4j.Argument;
+
+public class TextBuiltinTest extends CLIRepositoryTestCase {
+	public static class GitCliJGitWrapperParser {
+		@Argument(index = 0, metaVar = "metaVar_command", required = true, handler = SubcommandHandler.class)
+		TextBuiltin subcommand;
+
+		@Argument(index = 1, metaVar = "metaVar_arg")
+		List<String> arguments = new ArrayList<>();
+	}
+
+	private String[] runAndCaptureUsingInitRaw(String... args)
+			throws Exception {
+		CLIGitCommand.Result result = new CLIGitCommand.Result();
+
+		GitCliJGitWrapperParser bean = new GitCliJGitWrapperParser();
+		final CmdLineParser clp = new CmdLineParser(bean);
+		clp.parseArgument(args);
+
+		final TextBuiltin cmd = bean.subcommand;
+		cmd.initRaw(db, null, null, result.out, result.err);
+		cmd.execute(bean.arguments.toArray(new String[bean.arguments.size()]));
+		if (cmd.getOutputWriter() != null) {
+			cmd.getOutputWriter().flush();
+		}
+		if (cmd.getErrorWriter() != null) {
+			cmd.getErrorWriter().flush();
+		}
+		return result.outLines().toArray(new String[0]);
+	}
+
+	@Test
+	public void testCleanDeleteDirs() throws Exception {
+		try (Git git = new Git(db)) {
+			git.commit().setMessage("initial commit").call();
+
+			writeTrashFile("dir/file", "someData");
+			writeTrashFile("a", "someData");
+			writeTrashFile("b", "someData");
+
+			// all these files should be there
+			assertTrue(check(db, "a"));
+			assertTrue(check(db, "b"));
+			assertTrue(check(db, "dir/file"));
+
+			assertArrayOfLinesEquals(new String[] { "Removing a", "Removing b",
+					"Removing dir/" },
+					runAndCaptureUsingInitRaw("clean", "-d", "-f"));
+			assertFalse(check(db, "a"));
+			assertFalse(check(db, "b"));
+			assertFalse(check(db, "dir/file"));
+		}
+	}
+}

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/TextBuiltin.java

@@ -138,6 +138,31 @@ public abstract class TextBuiltin {
 		return true;
 	}
 
+	/**
+	 * Initializes the command to work with a repository, including setting the
+	 * output and error streams.
+	 *
+	 * @param repository
+	 *            the opened repository that the command should work on.
+	 * @param gitDir
+	 *            value of the {@code --git-dir} command line option, if
+	 *            {@code repository} is null.
+	 * @param input
+	 *            input stream from which input will be read
+	 * @param output
+	 *            output stream to which output will be written
+	 * @param error
+	 *            error stream to which errors will be written
+	 * @since 4.9
+	 */
+	public void initRaw(final Repository repository, final String gitDir,
+			InputStream input, OutputStream output, OutputStream error) {
+		this.ins = input;
+		this.outs = output;
+		this.errs = error;
+		init(repository, gitDir);
+	}
+
 	/**
 	 * Initialize the command to work with a repository.
 	 *
@@ -284,6 +309,14 @@ public abstract class TextBuiltin {
 		return errw;
 	}
 
+	/**
+	 * @return output writer, typically this is standard output.
+	 * @since 4.9
+	 */
+	public ThrowingPrintWriter getOutputWriter() {
+		return outw;
+	}
+
 	/**
 	 * @return the resource bundle that will be passed to args4j for purpose of
 	 *         string localization