Re: [JGIT] help needed to create a siimple commit

["Shawn O. Pearce" <spearce@spearce.org>]

Yann Simon <yann.simon.fr@gmail.com> wrote:
> I wrote the following unit test to learn how to make a commit
> with JGIT:
> 
> 	public void testASimpleCommit() throws IOException {
> 		
> 		GitIndex index = new GitIndex(db);
> 		index.filemode = Boolean.TRUE;
> 		
> 		File file;
> 		file = writeTrashFile("file1", "file1");
> 		
> 		index.add(trash, file);
> 		index.write();
> 		ObjectId objectId = index.writeTree();
> 		Tree tree = db.mapTree(objectId);
> 		tree.accept(new WriteTree(trash, db), TreeEntry.MODIFIED_ONLY);
> 		
> 		final Commit c1 = new Commit(db);
> 		c1.setAuthor(new PersonIdent(jauthor, 1154236443000L, -4 * 60));
> 		c1.setCommitter(new PersonIdent(jcommitter, 1154236443000L, -4 * 60));
> 		c1.setMessage("A Commit\n");
> 		c1.setTree(tree);
> 		assertEquals(tree.getTreeId(), c1.getTreeId());
> 		c1.commit();

You are missing the final step of updating the HEAD ref with the
commit.  Calling commit() on the Commit object only writes it to
the object database, this is similar to git-commit-tree.

Try adding on the end:

	RefUpdate ru = db.updateRef(Constants.HEAD);
	ru.setRefLogMessage("commit");
	ru.setNewObjectId(c1.getCommitId());
	assertSame(RefUpdate.Result.NEW, ru.update());

If your commit had parents, you might want to do instead:

	ru.setExpectedOldObjectId(oldHEAD);
	assertSame(RefUpdate.Result.FAST_FORWARD, ru.update());

where oldHEAD is the value of HEAD you read and used as the first
parent of the commit.  This ensures that the update method fails
if someone else has updated HEAD since you last read it.

The update method returns a number of different states, usually we
check its result with a switch statement as a number of states are
sometimes permissible in a context.  Sometimes though, you know it
has to be exactly one state, and everything else is a failure.

-- 
Shawn.