--- a/src/org/tmatesoft/hg/internal/NewlineFilter.java	Wed Nov 30 04:39:50 2011 +0100
+++ b/src/org/tmatesoft/hg/internal/NewlineFilter.java	Wed Nov 30 05:11:07 2011 +0100
@@ -21,8 +21,6 @@
 import static org.tmatesoft.hg.internal.KeywordFilter.copySlice;
 
 import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
@@ -44,6 +42,15 @@
 	private final boolean allowInconsistent;
 	private final boolean winToNix;
 
+	// next two factory methods for testsing purposes
+	public static NewlineFilter createWin2Nix(boolean allowMixed) {
+		return new NewlineFilter(!allowMixed, 0);
+	}
+	
+	public static NewlineFilter createNix2Win(boolean allowMixed) {
+		return new NewlineFilter(!allowMixed, 1);
+	}
+
 	private NewlineFilter(boolean failIfInconsistent, int transform) {
 		winToNix = transform == 0;
 		allowInconsistent = !failIfInconsistent;
@@ -250,25 +257,4 @@
 			return null;
 		}
 	}
-
-	public static void main(String[] args) throws Exception {
-		FileInputStream fis = new FileInputStream(new File("/temp/design.lf.txt"));
-		FileOutputStream fos = new FileOutputStream(new File("/temp/design.newline.out"));
-		ByteBuffer b = ByteBuffer.allocate(12);
-		NewlineFilter nlFilter = new NewlineFilter(true, 1);
-		while (fis.getChannel().read(b) != -1) {
-			b.flip(); // get ready to be read
-			ByteBuffer f = nlFilter.filter(b);
-			fos.getChannel().write(f); // XXX in fact, f may not be fully consumed
-			if (b.hasRemaining()) {
-				b.compact();
-			} else {
-				b.clear();
-			}
-		}
-		fis.close();
-		fos.flush();
-		fos.close();
-	}
-
 }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/org/tmatesoft/hg/test/TestNewlineFilter.java	Wed Nov 30 05:11:07 2011 +0100
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2011 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@hg4j.com
+ */
+package org.tmatesoft.hg.test;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.nio.ByteBuffer;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.tmatesoft.hg.internal.NewlineFilter;
+
+/**
+ *
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class TestNewlineFilter {
+
+	public static void main(String[] args) throws Exception {
+		FileInputStream fis = new FileInputStream(new File("/temp/design.lf.txt"));
+		FileOutputStream fos = new FileOutputStream(new File("/temp/design.newline.out"));
+		ByteBuffer b = ByteBuffer.allocate(12);
+		NewlineFilter nlFilter = NewlineFilter.createNix2Win(true);
+		while (fis.getChannel().read(b) != -1) {
+			b.flip(); // get ready to be read
+			ByteBuffer f = nlFilter.filter(b);
+			fos.getChannel().write(f); // XXX in fact, f may not be fully consumed
+			if (b.hasRemaining()) {
+				b.compact();
+			} else {
+				b.clear();
+			}
+		}
+		fis.close();
+		fos.flush();
+		fos.close();
+	}
+
+	// pure
+	private final String crlf_1 = "\r\nA\r\nBC\r\n\r\nDEF\r\n";
+	private final String lf_1 = "\nA\nBC\n\nDEF\n";
+	// mixed
+	private final String crlf_2 = "\r\nA\r\nBC\n\nDEF\r\n";
+	private final String lf_2 = "\nA\nBC\r\n\r\nDEF\n";
+	
+	@Test
+	public void testPure_CRLF_2_LF() {
+		final byte[] input = crlf_1.getBytes();
+		byte[] result = apply(NewlineFilter.createWin2Nix(false), input);
+		Assert.assertArrayEquals(lf_1.getBytes(), result);
+	}
+
+	@Test
+	public void testPure_LF_2_CRLF() {
+		final byte[] input = lf_1.getBytes();
+		byte[] result = apply(NewlineFilter.createNix2Win(false), input);
+		Assert.assertArrayEquals(crlf_1.getBytes(), result);
+	}
+
+	@Test
+	public void testRelaxedMixed_CRLF_2_LF() {
+		// mixed \n and \r\n to uniform \n
+		byte[] result = apply(NewlineFilter.createWin2Nix(true), crlf_2.getBytes());
+		Assert.assertArrayEquals(lf_1.getBytes(), result);
+	}
+
+	@Test
+	public void testRelaxedMixed_LF_2_CRLF() {
+		// mixed \n and \r\n to uniform \r\n
+		byte[] result = apply(NewlineFilter.createNix2Win(true), lf_2.getBytes());
+		Assert.assertArrayEquals(crlf_1.getBytes(), result);
+	}
+
+	@Test
+	public void testStrictMixed_CRLF_2_LF() {
+		try {
+			byte[] result = apply(NewlineFilter.createWin2Nix(false), crlf_2.getBytes());
+			Assert.fail("Shall fail when eol.only-consistent is true:" + new String(result));
+		} catch (RuntimeException ex) {
+			// fine
+		}
+	}
+
+	@Test
+	public void testStrictMixed_LF_2_CRLF() {
+		try {
+			byte[] result = apply(NewlineFilter.createNix2Win(false), lf_2.getBytes());
+			Assert.fail("Shall fail when eol.only-consistent is true:" + new String(result));
+		} catch (RuntimeException ex) {
+			// fine
+		}
+	}
+
+
+	@Test
+	public void testNoConversionNeeded_LF_2_LF() {
+		final byte[] input = lf_1.getBytes();
+		Assert.assertTrue("sanity", indexOf(input, '\r') == -1);
+		byte[] result = apply(NewlineFilter.createWin2Nix(false), input);
+		Assert.assertArrayEquals(input, result);
+	}
+
+	@Test
+	public void testNoConversionNeeded_CRLF_2_CRLF() {
+		final byte[] input = crlf_1.getBytes();
+		byte[] result = apply(NewlineFilter.createNix2Win(false), input);
+		Assert.assertArrayEquals(input, result);
+	}
+
+	private static byte[] apply(NewlineFilter nlFilter, byte[] input) {
+		ByteBuffer result = nlFilter.filter(ByteBuffer.wrap(input));
+		byte[] res = new byte[result.remaining()];
+		result.get(res);
+		return res;
+	}
+
+	private static int indexOf(byte[] arr, int val) {
+		for (int i = 0; i < arr.length; i++) {
+			if (arr[i] == val) {
+				return i;
+			}
+		}
+		return -1;
+	}
+}