History log in sub directory - libgit2sharp

Question

I'm trying to figure out how to get the commit log for a sub directory. According to this thread, it should work fine in libgit2sharp.
For testing I'm using a small repo, https://github.com/ornatwork/nugetpackages.git that has 8 total entries for the whole repository.
I cloned it locally in root c:/nugetpackages, from that folder I can do.
git log -- devbox
on the command line and I will get two commit entries for the /devbox sub directory as expected.
Sample Xunit test code to do the same using libgit2sharp
[Fact]
public void testSub()
{
// Extract the git commit history
using (var repo = new Repository(#"C:\nugetpackages"))
{
Trace.WriteLine("repo count=" + repo.Commits.Count());
// absolute path
IEnumerable<LogEntry> history = repo.Commits.QueryBy(#"C:\nugetpackages\devbox");
Trace.WriteLine("subdir count=" + history.Count());
}
}
I'm expecting count of 8 and 2, but this is what I get.
repo count=8
subdir count=0
What am I missing ?

Answer 1

Use a relative path from the repository's base diretory:
using (var repo = new Repository(#"/Users/sushi/code/sushi/Xamarin.Forms.Renderer.Tests"))
{
D.WriteLine("repo count=" + repo.Commits.Count());
IEnumerable<LogEntry> history = repo.Commits.QueryBy(#"AlarmSO");
D.WriteLine("subdir count=" + history.Count());
}
ref: FileHistoryFixture.cs
Update:
Follow up, is there a way to combine subdir with a filter, for example. CommitFilter filter = new CommitFilter(); filter.FirstParentOnly = true;
Not sure if this is what you are looking for... if not please in a new question, thanks.
using (var repo = new Repository(#"/Users/sushi/code/sushi/RealmJson"))
{
var subDir = "media";
var commits = repo.Commits.QueryBy(new CommitFilter { FirstParentOnly = true }).Where(
(Commit c) => c.Tree.Any(
(TreeEntry te) => te.Path.StartsWith(subDir, StringComparison.Ordinal)));
foreach (var commit in commits)
{
D.WriteLine($"{commit.Sha} : {commit.MessageShort}");
}
}