Add test for reflog part of ResetCommand

The reflog message fix was done in
I4f1c3cd6b2cf543be213f061afb94223062dde51

Change-Id: I44817ccf4bf226ed3e4ce6fb2d923e88788221dd
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

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

@@ -42,6 +42,7 @@
  */
 package org.eclipse.jgit.api;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
@@ -116,6 +117,7 @@ public class ResetCommandTest extends RepositoryTestCase {
 			NoHeadException, NoMessageException, ConcurrentRefUpdateException,
 			WrongRepositoryStateException {
 		setupRepository();
+		ObjectId prevHead = db.resolve(Constants.HEAD);
 		git.reset().setMode(ResetType.HARD).setRef(initialCommit.getName())
 				.call();
 		// check if HEAD points to initial commit now
@@ -128,6 +130,7 @@ public class ResetCommandTest extends RepositoryTestCase {
 		String fileInIndexPath = indexFile.getAbsolutePath();
 		assertFalse(inHead(fileInIndexPath));
 		assertFalse(inIndex(indexFile.getName()));
+		assertReflog(prevHead, head);
 	}
 
 	@Test
@@ -136,6 +139,7 @@ public class ResetCommandTest extends RepositoryTestCase {
 			NoHeadException, NoMessageException, ConcurrentRefUpdateException,
 			WrongRepositoryStateException {
 		setupRepository();
+		ObjectId prevHead = db.resolve(Constants.HEAD);
 		git.reset().setMode(ResetType.SOFT).setRef(initialCommit.getName())
 				.call();
 		// check if HEAD points to initial commit now
@@ -148,6 +152,7 @@ public class ResetCommandTest extends RepositoryTestCase {
 		String fileInIndexPath = indexFile.getAbsolutePath();
 		assertFalse(inHead(fileInIndexPath));
 		assertTrue(inIndex(indexFile.getName()));
+		assertReflog(prevHead, head);
 	}
 
 	@Test
@@ -156,6 +161,7 @@ public class ResetCommandTest extends RepositoryTestCase {
 			NoHeadException, NoMessageException, ConcurrentRefUpdateException,
 			WrongRepositoryStateException {
 		setupRepository();
+		ObjectId prevHead = db.resolve(Constants.HEAD);
 		git.reset().setMode(ResetType.MIXED).setRef(initialCommit.getName())
 				.call();
 		// check if HEAD points to initial commit now
@@ -168,6 +174,33 @@ public class ResetCommandTest extends RepositoryTestCase {
 		String fileInIndexPath = indexFile.getAbsolutePath();
 		assertFalse(inHead(fileInIndexPath));
 		assertFalse(inIndex(indexFile.getName()));
+
+		assertReflog(prevHead, head);
+	}
+
+	private void assertReflog(ObjectId prevHead, ObjectId head)
+			throws IOException {
+		// Check the reflog for HEAD
+		String actualHeadMessage = db.getReflogReader(Constants.HEAD)
+				.getLastEntry().getComment();
+		String expectedHeadMessage = head.getName() + ": updating HEAD";
+		assertEquals(expectedHeadMessage, actualHeadMessage);
+		assertEquals(head.getName(), db.getReflogReader(Constants.HEAD)
+				.getLastEntry().getNewId().getName());
+		assertEquals(prevHead.getName(), db
+				.getReflogReader(Constants.HEAD).getLastEntry().getOldId()
+				.getName());
+
+		// The reflog for master contains the same as the one for HEAD
+		String actualMasterMessage = db.getReflogReader("refs/heads/master")
+				.getLastEntry().getComment();
+		String expectedMasterMessage = head.getName() + ": updating HEAD"; // yes!
+		assertEquals(expectedMasterMessage, actualMasterMessage);
+		assertEquals(head.getName(), db.getReflogReader(Constants.HEAD)
+				.getLastEntry().getNewId().getName());
+		assertEquals(prevHead.getName(),
+				db.getReflogReader("refs/heads/master").getLastEntry()
+						.getOldId().getName());
 	}
 
 	/**